WIP: commands: split Command trait into req + res parts

Cargo.toml

@@ -13,6 +13,7 @@ rust-version = "1.85.0"
 [dependencies]
 chrono = { version = "0.4.42", features = ["serde"] }
 lalrpop-util = { version = "0.22.2", features = ["lexer"] }
+paste = "1.0.15"
 serde = { version = "1.0.228", features = ["derive"] }
 
 [dev-dependencies]

src/commands.rs

@@ -28,73 +28,342 @@ pub use reflection::*;
 pub use stickers::*;
 pub use stored_playlists::*;
 
-/// A trait modelling the request/response pair of a single MPD command.
-pub trait Command {
-    /// The request sent from the client to the server
-    type Request;
-
-    /// The response sent from the server to the client
-    type Response;
-
+/// A trait modelling a single MPD command request.
+pub trait CommandRequest<'a>
+where
+    Self: Sized,
+{
     /// The command name used within the protocol
     const COMMAND: &'static str;
 
+    /// Converts this specific request type to it's corresponding variant in the generic Request enum.
+    fn into_request_enum(self) -> Request;
+
+    /// Converts from the generic Request enum to this specific request type.
+    ///
+    /// If the enum variant does not match this type, returns None.
+    fn from_request_enum(request: Request) -> Option<Self>;
+
+    /// Serializes the request into a String.
+    fn serialize(&self) -> String;
+
+    /// Parses the request from its tokenized parts.
+    /// See also [`parse_raw`].
+    fn parse(parts: RequestTokenizer<'a>) -> Result<Self, RequestParserError>;
+
+    /// Parses the request from its raw string representation.
+    ///
+    /// This assumes the raw string starts with the command name, e.g.
+    /// `command_name arg1 "arg2 arg3"`
+    fn parse_raw(raw: &'a str) -> Result<Self, RequestParserError> {
+        let (line, rest) = raw
+            .split_once('\n')
+            .ok_or(RequestParserError::UnexpectedEOF)?;
+
+        debug_assert!(rest.is_empty());
+
+        let mut tokenized = RequestTokenizer::new(line);
+
+        let command_name_token_length = Self::COMMAND.split_ascii_whitespace().count();
+        let mut command_name = Vec::with_capacity(command_name_token_length);
+        for _ in 0..command_name_token_length {
+            let token = tokenized
+                .next()
+                .ok_or(RequestParserError::SyntaxError(0, line.to_string()))?;
+            command_name.push(token);
+        }
+        let command_name = command_name.join(" ");
+
+        if command_name != Self::COMMAND {
+            return Err(RequestParserError::SyntaxError(0, line.to_string()));
+        }
+
+        Self::parse(tokenized)
+    }
+}
+
+/// A trait modelling a single MPD command response.
+pub trait CommandResponse<'a>
+where
+    Self: Sized,
+{
+    /// Converts this specific response type to it's corresponding variant in the generic Response enum.
+    fn into_response_enum(self) -> crate::Response;
+
+    /// Converts from the generic Response enum to this specific response type.
+    ///
+    /// If the enum variant does not match this type, returns None.
+    fn from_response_enum(response: crate::Response) -> Option<Self>;
+
+    /// Serializes the response into a Vec<u8>.
+    // fn serialize(&self) -> Vec<u8>;
+
+    /// Parses the response from its tokenized parts.
+    /// See also [`parse_raw`].
+    fn parse(parts: ResponseAttributes<'a>) -> Result<Self, ResponseParserError<'a>>;
+
+    /// Parses the response from its raw byte representation.
+    fn parse_raw(raw: &'a [u8]) -> Result<Self, ResponseParserError<'a>> {
+        Self::parse(ResponseAttributes::new_from_bytes(raw))
+    }
+}
+
+/// A trait modelling the request/response pair of a single MPD command.
+pub trait Command<'req, 'res> {
+    /// The request sent from the client to the server
+    type Request: CommandRequest<'req>;
+    /// The response sent from the server to the client
+    type Response: CommandResponse<'res>;
+
+    /// The command name used within the protocol
+    const COMMAND: &'static str = Self::Request::COMMAND;
+
     /// Serialize the request into a string.
     /// This should optimally produce an input that can be parsed by [`parse_request`]
-    fn serialize_request(&self, request: Self::Request) -> String;
-
+    fn serialize_request(&self, request: Self::Request) -> String {
+        request.serialize().to_owned()
+    }
     /// Serialize the request into a bytestring.
     fn serialize_request_to_bytes(&self, request: Self::Request) -> Vec<u8> {
         self.serialize_request(request).into_bytes()
     }
 
-    // fn serialize_response(&self) -> String;
-    // fn serialize_response_to_bytes(&self) -> Vec<u8> {
-    //     self.serialize_response().into_bytes()
-    // }
-
-    /// Parse the request from its tokenized parts.
-    ///
-    /// Note that this assumes only the parts after the command name are passed in, e.g.
-    ///
-    /// ```ignore
-    /// arg1 "arg2 arg3"
-    /// ```
-    fn parse_request(parts: RequestTokenizer<'_>) -> Result<Self::Request, RequestParserError>;
-
-    /// Parse the raw request string into a request and the remaining unparsed string.
-    /// This assumes the raw string starts with the command name, e.g.
-    ///
-    /// ```ignore
-    /// command_name arg1 "arg2 arg3"
-    /// ```
-    fn parse_raw_request(raw: &str) -> Result<(Self::Request, &str), RequestParserError> {
-        let (line, rest) = raw
-            .split_once('\n')
-            .ok_or(RequestParserError::UnexpectedEOF)?;
-        let mut tokenized = RequestTokenizer::new(line);
-
-        let command_name = tokenized
-            .next()
-            .ok_or(RequestParserError::SyntaxError(0, line.to_string()))?
-            .trim();
-
-        debug_assert!(command_name == Self::COMMAND);
-
-        Self::parse_request(tokenized).map(|req| (req, rest))
+    /// Parse the request from its tokenized parts. See also [`parse_raw_request`].
+    fn parse_request(parts: RequestTokenizer<'req>) -> Result<Self::Request, RequestParserError> {
+        Self::Request::parse(parts)
     }
 
-    /// Parse the response from its tokenized parts.
-    /// See also [`parse_raw_response`].
-    fn parse_response(parts: ResponseAttributes<'_>) -> ResponseParserResult<'_, Self::Response>;
+    /// Parse the raw request string into a request.
+    /// This assumes the raw string starts with the command name, e.g. `command_name arg1 "arg2 arg3"`
+    fn parse_raw_request(raw: &'req str) -> Result<Self::Request, RequestParserError> {
+        Self::Request::parse_raw(raw)
+    }
 
+    /// Serialize the response into a string.
+    // fn serialize_response(&self, response: Self::Response) -> String {
+
+    /// Parse the response from its tokenized parts. See also [`parse_raw_response`].
+    fn parse_response(
+        parts: ResponseAttributes<'res>,
+    ) -> Result<Self::Response, ResponseParserError<'res>> {
+        Self::Response::parse(parts)
+    }
     /// Parse the raw response string into a response.
-    fn parse_raw_response(raw: &str) -> ResponseParserResult<'_, Self::Response> {
-        Self::parse_response(ResponseAttributes::new(raw))
+    fn parse_raw_response(raw: &'res [u8]) -> Result<Self::Response, ResponseParserError<'res>> {
+        Self::Response::parse_raw(raw)
     }
 }
 
-// pub type RequestParserResult<'a> = ;
+/// Request/response implementation helpers
+
+macro_rules! empty_command_request {
+    ($name:ident, $command_name:expr) => {
+        paste::paste! {
+            #[derive(Debug, Clone, PartialEq, serde::Serialize, serde::Deserialize)]
+            pub struct [<$name Request>];
+        }
+
+        impl crate::commands::CommandRequest<'_> for paste::paste! { [<$name Request>] } {
+            const COMMAND: &'static str = $command_name;
+
+            fn into_request_enum(self) -> crate::Request {
+                match Self::COMMAND {
+                    $command_name => crate::Request::$name,
+                    _ => unimplemented!(),
+                }
+            }
+
+            fn from_request_enum(request: crate::Request) -> Option<Self> {
+                match (Self::COMMAND, request) {
+                    ($command_name, crate::Request::$name) => {
+                        Some(paste::paste! { [<$name Request>] })
+                    }
+                    _ => None,
+                }
+            }
+
+            fn serialize(&self) -> String {
+                Self::COMMAND.to_string()
+            }
+
+            fn parse(
+                mut parts: crate::commands::RequestTokenizer<'_>,
+            ) -> Result<Self, crate::commands::RequestParserError> {
+                debug_assert!(parts.next().is_none());
+
+                Ok(paste::paste! { [<$name Request>] })
+            }
+        }
+    };
+}
+
+macro_rules! empty_command_response {
+    ($name:ident) => {
+        paste::paste! {
+            #[derive(Debug, Clone, PartialEq, serde::Serialize, serde::Deserialize)]
+            pub struct [<$name Response>];
+        }
+
+        impl crate::commands::CommandResponse<'_> for paste::paste! { [<$name Response>] } {
+            fn into_response_enum(self) -> crate::Response {
+                todo!()
+            }
+
+            fn from_response_enum(_response: crate::Response) -> Option<Self> {
+                todo!()
+            }
+
+            fn parse(
+                _parts: crate::commands::ResponseAttributes<'_>,
+            ) -> Result<Self, crate::commands::ResponseParserError<'_>> {
+                debug_assert!(_parts.is_empty());
+                Ok(paste::paste! { [<$name Response>] })
+            }
+        }
+    };
+}
+
+macro_rules! single_item_command_request {
+    ($name:ident, $command_name:expr, $item_type:ty) => {
+        paste::paste! {
+            #[derive(Debug, Clone, PartialEq, serde::Serialize, serde::Deserialize)]
+            pub struct [<$name Request>] ($item_type);
+        }
+
+        impl crate::commands::CommandRequest<'_> for paste::paste! { [<$name Request>] } {
+            const COMMAND: &'static str = $command_name;
+
+            fn into_request_enum(self) -> crate::Request {
+                match Self::COMMAND {
+                    $command_name => crate::Request::$name(self.0),
+                    _ => unimplemented!(),
+                }
+            }
+
+            fn from_request_enum(request: crate::Request) -> Option<Self> {
+                match (Self::COMMAND, request) {
+                    ($command_name, crate::Request::$name(item)) => {
+                        Some(paste::paste! { [<$name Request>] ( item ) })
+                    }
+                    _ => None,
+                }
+            }
+
+            fn serialize(&self) -> String {
+                format!("{} {}", Self::COMMAND, self.0)
+            }
+
+            fn parse(
+                mut parts: crate::commands::RequestTokenizer<'_>,
+            ) -> Result<Self, crate::commands::RequestParserError> {
+                let item_token = parts
+                    .next()
+                    .ok_or(crate::commands::RequestParserError::UnexpectedEOF)?;
+                let item = item_token.parse::<$item_type>().map_err(|_| {
+                    crate::commands::RequestParserError::SyntaxError(0, item_token.to_owned())
+                })?;
+
+                debug_assert!(parts.next().is_none());
+
+                Ok(paste::paste! { [<$name Request>] ( item ) })
+            }
+        }
+    };
+}
+
+macro_rules! single_item_command_response {
+    ($name:ident, $item_name:expr, $item_type:ty) => {
+        paste::paste! {
+            #[derive(Debug, Clone, PartialEq, serde::Serialize, serde::Deserialize)]
+            pub struct [<$name Response>] ( $item_type );
+        }
+
+        impl crate::commands::CommandResponse<'_> for paste::paste! { [<$name Response>] } {
+            fn into_response_enum(self) -> crate::Response {
+                todo!()
+            }
+
+            fn from_response_enum(_response: crate::Response) -> Option<Self> {
+                todo!()
+            }
+
+            fn parse(
+                parts: crate::commands::ResponseAttributes<'_>,
+            ) -> Result<Self, crate::commands::ResponseParserError<'_>> {
+                let map = parts.into_map()?;
+
+                debug_assert!(map.len() == 1, "Expected only one property in response");
+
+                let item_token = map.get($item_name).ok_or(
+                    crate::commands::ResponseParserError::MissingProperty($item_name),
+                )?;
+                let item_ = crate::response_tokenizer::expect_property_type!(
+                    Some(item_token),
+                    $item_name,
+                    Text
+                );
+                let item = item_.parse::<$item_type>().map_err(|_| {
+                    crate::commands::ResponseParserError::InvalidProperty($item_name, item_)
+                })?;
+
+                Ok(paste::paste! { [<$name Response>] ( item ) })
+            }
+        }
+    };
+}
+
+macro_rules! multi_item_command_response {
+    ($name:ident, $item_name:expr, $item_type:ty) => {
+        paste::paste! {
+            #[derive(Debug, Clone, PartialEq, serde::Serialize, serde::Deserialize)]
+            pub struct [<$name Response>] ( Vec<$item_type> );
+        }
+
+        impl crate::commands::CommandResponse<'_> for paste::paste! { [<$name Response>] } {
+            fn into_response_enum(self) -> crate::Response {
+                todo!()
+            }
+
+            fn from_response_enum(_response: crate::Response) -> Option<Self> {
+                todo!()
+            }
+
+            fn parse(
+                mut parts: crate::commands::ResponseAttributes<'_>,
+            ) -> Result<Self, crate::commands::ResponseParserError<'_>> {
+                let parts_: Vec<_> = parts.into_vec()?;
+
+                if let Some((k, _)) = parts_.iter().find(|(k, _)| *k != $item_name) {
+                    return Err(ResponseParserError::UnexpectedProperty(k));
+                }
+
+                let mut items = Vec::with_capacity(parts_.len());
+
+                while let Some(value) = parts_.into_iter().next() {
+                    let unwrapped_value = expect_property_type!(Some(value.1), $item_name, Text);
+                    let parsed_value = unwrapped_value.parse::<$item_type>().map_err(|_| {
+                        crate::commands::ResponseParserError::InvalidProperty(
+                            $item_name,
+                            unwrapped_value,
+                        )
+                    })?;
+
+                    items.push(parsed_value);
+                }
+
+                Ok(paste::paste! { [<$name Response>] ( items ) })
+            }
+        }
+    };
+}
+
+pub(crate) use empty_command_request;
+pub(crate) use empty_command_response;
+pub(crate) use multi_item_command_response;
+pub(crate) use single_item_command_request;
+pub(crate) use single_item_command_response;
+
+///
 
 #[derive(Debug, Clone, PartialEq)]
 pub enum RequestParserError {

src/commands/audio_output_devices.rs

@@ -4,8 +4,8 @@ pub mod outputs;
 pub mod outputset;
 pub mod toggleoutput;
 
-pub use disableoutput::DisableOutput;
-pub use enableoutput::EnableOutput;
-pub use outputs::Outputs;
-pub use outputset::OutputSet;
-pub use toggleoutput::ToggleOutput;
+pub use disableoutput::*;
+pub use enableoutput::*;
+pub use outputs::*;
+pub use outputset::*;
+pub use toggleoutput::*;

src/commands/audio_output_devices/disableoutput.rs

@@ -1,38 +1,15 @@
 use crate::{
-    commands::{Command, RequestParserError, ResponseParserError},
+    commands::{Command, empty_command_response, single_item_command_request},
     common::types::AudioOutputId,
-    request_tokenizer::RequestTokenizer,
-    response_tokenizer::ResponseAttributes,
 };
 
 pub struct DisableOutput;
 
-pub type DisableOutputRequest = AudioOutputId;
+single_item_command_request!(DisableOutput, "disableoutput", AudioOutputId);
 
-impl Command for DisableOutput {
+empty_command_response!(DisableOutput);
+
+impl Command<'_, '_> for DisableOutput {
     type Request = DisableOutputRequest;
-    type Response = ();
-    const COMMAND: &'static str = "disableoutput";
-
-    fn serialize_request(&self, request: Self::Request) -> String {
-        format!("{} {}", Self::COMMAND, request)
-    }
-
-    fn parse_request(mut parts: RequestTokenizer<'_>) -> Result<Self::Request, RequestParserError> {
-        let output_id = parts.next().ok_or(RequestParserError::UnexpectedEOF)?;
-        let output_id = output_id
-            .parse()
-            .map_err(|_| RequestParserError::SyntaxError(0, output_id.to_owned()))?;
-
-        debug_assert!(parts.next().is_none());
-
-        Ok(output_id)
-    }
-
-    fn parse_response(
-        parts: ResponseAttributes<'_>,
-    ) -> Result<Self::Response, ResponseParserError<'_>> {
-        debug_assert!(parts.is_empty());
-        Ok(())
-    }
+    type Response = DisableOutputResponse;
 }

src/commands/audio_output_devices/enableoutput.rs

@@ -1,5 +1,8 @@
 use crate::{
-    commands::{Command, RequestParserError, ResponseParserError},
+    commands::{
+        Command, CommandRequest, CommandResponse, RequestParserError, ResponseParserError,
+        empty_command_response, single_item_command_request,
+    },
     common::types::AudioOutputId,
     request_tokenizer::RequestTokenizer,
     response_tokenizer::ResponseAttributes,
@@ -7,32 +10,11 @@ use crate::{
 
 pub struct EnableOutput;
 
-pub type EnableOutputRequest = AudioOutputId;
+single_item_command_request!(EnableOutput, "enableoutput", AudioOutputId);
 
-impl Command for EnableOutput {
+empty_command_response!(EnableOutput);
+
+impl Command<'_, '_> for EnableOutput {
     type Request = EnableOutputRequest;
-    type Response = ();
-    const COMMAND: &'static str = "enableoutput";
-
-    fn serialize_request(&self, request: Self::Request) -> String {
-        format!("{} {}", Self::COMMAND, request)
-    }
-
-    fn parse_request(mut parts: RequestTokenizer<'_>) -> Result<Self::Request, RequestParserError> {
-        let output_id = parts.next().ok_or(RequestParserError::UnexpectedEOF)?;
-        let output_id = output_id
-            .parse()
-            .map_err(|_| RequestParserError::SyntaxError(0, output_id.to_owned()))?;
-
-        debug_assert!(parts.next().is_none());
-
-        Ok(output_id)
-    }
-
-    fn parse_response(
-        parts: ResponseAttributes<'_>,
-    ) -> Result<Self::Response, ResponseParserError<'_>> {
-        debug_assert!(parts.is_empty());
-        Ok(())
-    }
+    type Response = EnableOutputResponse;
 }

src/commands/audio_output_devices/outputs.rs

@@ -3,7 +3,10 @@ use std::collections::HashMap;
 use serde::{Deserialize, Serialize};
 
 use crate::{
-    commands::{Command, RequestParserError, ResponseParserError},
+    commands::{
+        Command, CommandRequest, CommandResponse, RequestParserError, ResponseParserError,
+        empty_command_request,
+    },
     common::types::AudioOutputId,
     request_tokenizer::RequestTokenizer,
     response_tokenizer::{ResponseAttributes, expect_property_type},
@@ -11,6 +14,8 @@ use crate::{
 
 pub struct Outputs;
 
+empty_command_request!(Outputs, "outputs");
+
 #[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
 pub struct Output {
     pub id: AudioOutputId,
@@ -22,23 +27,16 @@ pub struct Output {
 
 pub type OutputsResponse = Vec<Output>;
 
-impl Command for Outputs {
-    type Request = ();
-    type Response = OutputsResponse;
-    const COMMAND: &'static str = "outputs";
-
-    fn serialize_request(&self, _: Self::Request) -> String {
-        Self::COMMAND.to_string()
+impl CommandResponse<'_> for OutputsResponse {
+    fn into_response_enum(self) -> crate::Response {
+        todo!()
     }
 
-    fn parse_request(mut parts: RequestTokenizer<'_>) -> Result<Self::Request, RequestParserError> {
-        debug_assert!(parts.next().is_none());
-        Ok(())
+    fn from_response_enum(response: crate::Response) -> Option<Self> {
+        todo!()
     }
 
-    fn parse_response(
-        parts: ResponseAttributes<'_>,
-    ) -> Result<Self::Response, ResponseParserError<'_>> {
+    fn parse(parts: ResponseAttributes<'_>) -> Result<Self, ResponseParserError<'_>> {
         let mut outputs = Vec::new();
 
         let mut id: Option<AudioOutputId> = None;
@@ -118,6 +116,11 @@ impl Command for Outputs {
     }
 }
 
+impl Command<'_, '_> for Outputs {
+    type Request = OutputsRequest;
+    type Response = OutputsResponse;
+}
+
 #[cfg(test)]
 mod tests {
     use indoc::indoc;
@@ -138,7 +141,7 @@ mod tests {
             attribute: fifo_path=/tmp/empidee-visualizer.fifo
             OK
         "};
-        let result = Outputs::parse_raw_response(input);
+        let result = Outputs::parse_raw_response(input.as_bytes());
         assert_eq!(
             result,
             Ok(vec![

src/commands/audio_output_devices/outputset.rs

@@ -1,7 +1,10 @@
 use serde::{Deserialize, Serialize};
 
 use crate::{
-    commands::{Command, RequestParserError, ResponseParserError},
+    commands::{
+        Command, CommandRequest, CommandResponse, RequestParserError, ResponseParserError,
+        empty_command_response,
+    },
     common::types::AudioOutputId,
     request_tokenizer::RequestTokenizer,
     response_tokenizer::ResponseAttributes,
@@ -16,22 +19,37 @@ pub struct OutputSetRequest {
     pub attribute_value: String,
 }
 
-impl Command for OutputSet {
-    type Request = OutputSetRequest;
-    type Response = ();
+impl CommandRequest<'_> for OutputSetRequest {
     const COMMAND: &'static str = "outputset";
 
-    fn serialize_request(&self, request: Self::Request) -> String {
+    fn into_request_enum(self) -> crate::Request {
+        crate::Request::OutputSet(self.output_id, self.attribute_name, self.attribute_value)
+    }
+
+    fn from_request_enum(request: crate::Request) -> Option<Self> {
+        match request {
+            crate::Request::OutputSet(output_id, attribute_name, attribute_value) => {
+                Some(OutputSetRequest {
+                    output_id,
+                    attribute_name,
+                    attribute_value,
+                })
+            }
+            _ => None,
+        }
+    }
+
+    fn serialize(&self) -> String {
         format!(
             "{} {} {} {}",
             Self::COMMAND,
-            request.output_id,
-            request.attribute_name,
-            request.attribute_value
+            self.output_id,
+            self.attribute_name,
+            self.attribute_value
         )
     }
 
-    fn parse_request(mut parts: RequestTokenizer<'_>) -> Result<Self::Request, RequestParserError> {
+    fn parse(mut parts: RequestTokenizer<'_>) -> Result<Self, RequestParserError> {
         let output_id = parts.next().ok_or(RequestParserError::UnexpectedEOF)?;
         let output_id = output_id
             .parse()
@@ -47,11 +65,11 @@ impl Command for OutputSet {
             attribute_value: attribute_value.to_string(),
         })
     }
-
-    fn parse_response(
-        parts: ResponseAttributes<'_>,
-    ) -> Result<Self::Response, ResponseParserError<'_>> {
-        debug_assert!(parts.is_empty());
-        Ok(())
-    }
+}
+
+empty_command_response!(OutputSet);
+
+impl Command<'_, '_> for OutputSet {
+    type Request = OutputSetRequest;
+    type Response = OutputSetResponse;
 }

src/commands/audio_output_devices/toggleoutput.rs

@@ -1,5 +1,8 @@
 use crate::{
-    commands::{Command, RequestParserError, ResponseParserError},
+    commands::{
+        Command, CommandRequest, CommandResponse, RequestParserError, ResponseParserError,
+        empty_command_response, single_item_command_request,
+    },
     common::types::AudioOutputId,
     request_tokenizer::RequestTokenizer,
     response_tokenizer::ResponseAttributes,
@@ -7,32 +10,11 @@ use crate::{
 
 pub struct ToggleOutput;
 
-pub type ToggleOutputRequest = AudioOutputId;
+single_item_command_request!(ToggleOutput, "toggleoutput", AudioOutputId);
 
-impl Command for ToggleOutput {
+empty_command_response!(ToggleOutput);
+
+impl Command<'_, '_> for ToggleOutput {
     type Request = ToggleOutputRequest;
-    type Response = ();
-    const COMMAND: &'static str = "toggleoutput";
-
-    fn serialize_request(&self, request: Self::Request) -> String {
-        format!("{} {}", Self::COMMAND, request)
-    }
-
-    fn parse_request(mut parts: RequestTokenizer<'_>) -> Result<Self::Request, RequestParserError> {
-        let output_id = parts.next().ok_or(RequestParserError::UnexpectedEOF)?;
-        let output_id = output_id
-            .parse()
-            .map_err(|_| RequestParserError::SyntaxError(0, output_id.to_owned()))?;
-
-        debug_assert!(parts.next().is_none());
-
-        Ok(output_id)
-    }
-
-    fn parse_response(
-        parts: ResponseAttributes<'_>,
-    ) -> Result<Self::Response, ResponseParserError<'_>> {
-        debug_assert!(parts.is_empty());
-        Ok(())
-    }
+    type Response = ToggleOutputResponse;
 }

src/commands/client_to_client/channels.rs

@@ -1,7 +1,10 @@
 use serde::{Deserialize, Serialize};
 
 use crate::{
-    commands::{Command, RequestParserError, ResponseParserError},
+    commands::{
+        Command, CommandRequest, CommandResponse, RequestParserError, ResponseParserError,
+        empty_command_request,
+    },
     common::types::ChannelName,
     request_tokenizer::RequestTokenizer,
     response_tokenizer::{ResponseAttributes, expect_property_type},
@@ -9,29 +12,23 @@ use crate::{
 
 pub struct Channels;
 
+empty_command_request!(Channels, "channels");
+
 #[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
 pub struct ChannelsResponse {
     pub channels: Vec<ChannelName>,
 }
 
-impl Command for Channels {
-    type Request = ();
-    type Response = ChannelsResponse;
-    const COMMAND: &'static str = "channels";
-
-    fn serialize_request(&self, _: Self::Request) -> String {
-        Self::COMMAND.to_string()
+impl<'a> CommandResponse<'a> for ChannelsResponse {
+    fn into_response_enum(self) -> crate::Response {
+        todo!()
     }
 
-    fn parse_request(mut parts: RequestTokenizer<'_>) -> Result<Self::Request, RequestParserError> {
-        debug_assert!(parts.next().is_none());
-
-        Ok(())
+    fn from_response_enum(response: crate::Response) -> Option<Self> {
+        todo!()
     }
 
-    fn parse_response(
-        parts: ResponseAttributes<'_>,
-    ) -> Result<Self::Response, ResponseParserError<'_>> {
+    fn parse(parts: ResponseAttributes<'_>) -> Result<Self, ResponseParserError<'_>> {
         let parts: Vec<_> = parts.into_vec()?;
         let mut channel_names = Vec::with_capacity(parts.len());
         for (key, value) in parts {
@@ -49,6 +46,11 @@ impl Command for Channels {
     }
 }
 
+impl Command<'_, '_> for Channels {
+    type Request = ChannelsRequest;
+    type Response = ChannelsResponse;
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;
@@ -63,7 +65,7 @@ mod tests {
             channels: baz
             OK
         "};
-        let response = Channels::parse_raw_response(response).unwrap();
+        let response = Channels::parse_raw_response(response.as_bytes()).unwrap();
         assert_eq!(
             response,
             ChannelsResponse {

src/commands/client_to_client/readmessages.rs

@@ -1,7 +1,10 @@
 use serde::{Deserialize, Serialize};
 
 use crate::{
-    commands::{Command, RequestParserError, ResponseParserError},
+    commands::{
+        Command, CommandRequest, CommandResponse, RequestParserError, ResponseParserError,
+        empty_command_request,
+    },
     common::types::ChannelName,
     request_tokenizer::RequestTokenizer,
     response_tokenizer::{ResponseAttributes, expect_property_type},
@@ -9,7 +12,10 @@ use crate::{
 
 pub struct ReadMessages;
 
-pub type ReadMessagesResponse = Vec<ReadMessagesResponseEntry>;
+empty_command_request!(ReadMessages, "readmessages");
+
+#[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
+pub struct ReadMessagesResponse(Vec<ReadMessagesResponseEntry>);
 
 #[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
 pub struct ReadMessagesResponseEntry {
@@ -17,24 +23,16 @@ pub struct ReadMessagesResponseEntry {
     message: String,
 }
 
-impl Command for ReadMessages {
-    type Request = ();
-    type Response = ReadMessagesResponse;
-    const COMMAND: &'static str = "readmessages";
-
-    fn serialize_request(&self, _: Self::Request) -> String {
-        Self::COMMAND.to_string()
+impl CommandResponse<'_> for ReadMessagesResponse {
+    fn into_response_enum(self) -> crate::Response {
+        todo!()
     }
 
-    fn parse_request(mut parts: RequestTokenizer<'_>) -> Result<Self::Request, RequestParserError> {
-        debug_assert!(parts.next().is_none());
-
-        Ok(())
+    fn from_response_enum(response: crate::Response) -> Option<Self> {
+        todo!()
     }
 
-    fn parse_response(
-        parts: ResponseAttributes<'_>,
-    ) -> Result<Self::Response, ResponseParserError<'_>> {
+    fn parse(parts: ResponseAttributes<'_>) -> Result<Self, ResponseParserError<'_>> {
         let parts: Vec<_> = parts.into_vec()?;
         debug_assert!(parts.len() % 2 == 0);
 
@@ -57,10 +55,15 @@ impl Command for ReadMessages {
             messages.push(ReadMessagesResponseEntry { channel, message });
         }
 
-        Ok(messages)
+        Ok(ReadMessagesResponse(messages))
     }
 }
 
+impl Command<'_, '_> for ReadMessages {
+    type Request = ReadMessagesRequest;
+    type Response = ReadMessagesResponse;
+}
+
 #[cfg(test)]
 mod tests {
     use indoc::indoc;
@@ -76,10 +79,10 @@ mod tests {
             message: message2
             OK
         "};
-        let result = ReadMessages::parse_raw_response(input);
+        let result = ReadMessages::parse_raw_response(input.as_bytes());
         assert_eq!(
             result,
-            Ok(vec![
+            Ok(ReadMessagesResponse(vec![
                 ReadMessagesResponseEntry {
                     channel: "channel1".parse().unwrap(),
                     message: "message1".to_string(),
@@ -88,7 +91,7 @@ mod tests {
                     channel: "channel2".parse().unwrap(),
                     message: "message2".to_string(),
                 },
-            ])
+            ]))
         );
     }
 }

src/commands/client_to_client/sendmessage.rs

@@ -1,7 +1,9 @@
 use serde::{Deserialize, Serialize};
 
 use crate::{
-    commands::{Command, RequestParserError, ResponseParserError},
+    commands::{
+        Command, CommandRequest, CommandResponse, RequestParserError, empty_command_response,
+    },
     common::types::ChannelName,
     request_tokenizer::RequestTokenizer,
     response_tokenizer::ResponseAttributes,
@@ -15,16 +17,27 @@ pub struct SendMessageRequest {
     pub message: String,
 }
 
-impl Command for SendMessage {
-    type Request = SendMessageRequest;
-    type Response = ();
+impl CommandRequest<'_> for SendMessageRequest {
     const COMMAND: &'static str = "sendmessage";
 
-    fn serialize_request(&self, request: Self::Request) -> String {
-        format!("{} {} {}", Self::COMMAND, request.channel, request.message)
+    fn into_request_enum(self) -> crate::Request {
+        crate::Request::SendMessage(self.channel, self.message)
     }
 
-    fn parse_request(mut parts: RequestTokenizer<'_>) -> Result<Self::Request, RequestParserError> {
+    fn from_request_enum(request: crate::Request) -> Option<Self> {
+        match request {
+            crate::Request::SendMessage(channel, message) => {
+                Some(SendMessageRequest { channel, message })
+            }
+            _ => None,
+        }
+    }
+
+    fn serialize(&self) -> String {
+        format!("{} {} {}", Self::COMMAND, self.channel, self.message)
+    }
+
+    fn parse(mut parts: RequestTokenizer<'_>) -> Result<Self, RequestParserError> {
         let channel = parts.next().ok_or(RequestParserError::UnexpectedEOF)?;
         let channel = channel
             .parse()
@@ -37,11 +50,11 @@ impl Command for SendMessage {
 
         Ok(SendMessageRequest { channel, message })
     }
-
-    fn parse_response(
-        parts: ResponseAttributes<'_>,
-    ) -> Result<Self::Response, ResponseParserError<'_>> {
-        debug_assert!(parts.is_empty());
-        Ok(())
-    }
+}
+
+empty_command_response!(SendMessage);
+
+impl Command<'_, '_> for SendMessage {
+    type Request = SendMessageRequest;
+    type Response = SendMessageResponse;
 }

src/commands/client_to_client/subscribe.rs

@@ -1,5 +1,8 @@
 use crate::{
-    commands::{Command, RequestParserError, ResponseParserError},
+    commands::{
+        Command, CommandRequest, RequestParserError, ResponseParserError, empty_command_response,
+        single_item_command_request,
+    },
     common::types::ChannelName,
     request_tokenizer::RequestTokenizer,
     response_tokenizer::ResponseAttributes,
@@ -7,30 +10,11 @@ use crate::{
 
 pub struct Subscribe;
 
-impl Command for Subscribe {
-    type Request = ChannelName;
-    type Response = ();
-    const COMMAND: &'static str = "subscribe";
+single_item_command_request!(Subscribe, "subscribe", ChannelName);
 
-    fn serialize_request(&self, request: Self::Request) -> String {
-        format!("{} {}", Self::COMMAND, request)
-    }
+empty_command_response!(Subscribe);
 
-    fn parse_request(mut parts: RequestTokenizer<'_>) -> Result<Self::Request, RequestParserError> {
-        let channel_name = parts.next().ok_or(RequestParserError::UnexpectedEOF)?;
-        let channel_name = channel_name
-            .parse()
-            .map_err(|_| RequestParserError::SyntaxError(0, channel_name.to_owned()))?;
-
-        debug_assert!(parts.next().is_none());
-
-        Ok(channel_name)
-    }
-
-    fn parse_response(
-        parts: ResponseAttributes<'_>,
-    ) -> Result<Self::Response, ResponseParserError<'_>> {
-        debug_assert!(parts.is_empty());
-        Ok(())
-    }
+impl Command<'_, '_> for Subscribe {
+    type Request = SubscribeRequest;
+    type Response = SubscribeResponse;
 }

src/commands/client_to_client/unsubscribe.rs

@@ -1,36 +1,19 @@
 use crate::{
-    commands::{Command, RequestParserError, ResponseParserError},
+    commands::{
+        Command, CommandRequest, RequestParserError, ResponseParserError, empty_command_response,
+        single, single_item_command_request,
+    },
     common::types::ChannelName,
     request_tokenizer::RequestTokenizer,
-    response_tokenizer::ResponseAttributes,
 };
 
 pub struct Unsubscribe;
 
-impl Command for Unsubscribe {
-    type Request = ChannelName;
-    type Response = ();
-    const COMMAND: &'static str = "unsubscribe";
+single_item_command_request!(Unsubscribe, "unsubscribe", ChannelName);
 
-    fn serialize_request(&self, request: Self::Request) -> String {
-        format!("{} {}", Self::COMMAND, request)
-    }
+empty_command_response!(Unsubscribe);
 
-    fn parse_request(mut parts: RequestTokenizer<'_>) -> Result<Self::Request, RequestParserError> {
-        let channel_name = parts.next().ok_or(RequestParserError::UnexpectedEOF)?;
-        let channel_name = channel_name
-            .parse()
-            .map_err(|_| RequestParserError::SyntaxError(0, channel_name.to_owned()))?;
-
-        debug_assert!(parts.next().is_none());
-
-        Ok(channel_name)
-    }
-
-    fn parse_response(
-        parts: ResponseAttributes<'_>,
-    ) -> Result<Self::Response, ResponseParserError<'_>> {
-        debug_assert!(parts.is_empty());
-        Ok(())
-    }
+impl Command<'_, '_> for Unsubscribe {
+    type Request = UnsubscribeRequest;
+    type Response = UnsubscribeResponse;
 }

src/commands/connection_settings/binary_limit.rs

@@ -1,33 +1,19 @@
 use crate::{
-    commands::{Command, RequestParserError, ResponseParserError},
+    commands::{
+        Command, RequestParserError, ResponseParserError, empty_command_request,
+        empty_command_response, single_item_command_request,
+    },
     request_tokenizer::RequestTokenizer,
     response_tokenizer::ResponseAttributes,
 };
 
 pub struct BinaryLimit;
 
-impl Command for BinaryLimit {
-    type Request = u64;
-    type Response = ();
-    const COMMAND: &'static str = "binarylimit";
+single_item_command_request!(BinaryLimit, "binarylimit", u64);
 
-    fn serialize_request(&self, request: Self::Request) -> String {
-        format!("{} {}", Self::COMMAND, request)
-    }
+empty_command_response!(BinaryLimit);
 
-    fn parse_request(mut parts: RequestTokenizer<'_>) -> Result<Self::Request, RequestParserError> {
-        let limit = parts.next().ok_or(RequestParserError::UnexpectedEOF)?;
-        let limit = limit
-            .parse()
-            .map_err(|_| RequestParserError::SyntaxError(0, limit.to_string()))?;
-        debug_assert!(parts.next().is_none());
-        Ok(limit)
-    }
-
-    fn parse_response(
-        parts: ResponseAttributes<'_>,
-    ) -> Result<Self::Response, ResponseParserError<'_>> {
-        debug_assert!(parts.is_empty());
-        Ok(())
-    }
+impl Command<'_, '_> for BinaryLimit {
+    type Request = BinaryLimitRequest;
+    type Response = BinaryLimitResponse;
 }

src/commands/connection_settings/close.rs

@@ -1,29 +1,19 @@
 use crate::{
-    commands::{Command, RequestParserError, ResponseParserError},
+    commands::{
+        Command, RequestParserError, ResponseParserError, empty_command_request,
+        empty_command_response,
+    },
     request_tokenizer::RequestTokenizer,
     response_tokenizer::ResponseAttributes,
 };
 
 pub struct Close;
 
-impl Command for Close {
-    type Request = ();
-    type Response = ();
-    const COMMAND: &'static str = "close";
+empty_command_request!(Close, "close");
 
-    fn serialize_request(&self, _request: Self::Request) -> String {
-        Self::COMMAND.to_string()
-    }
+empty_command_response!(Close);
 
-    fn parse_request(mut parts: RequestTokenizer<'_>) -> Result<Self::Request, RequestParserError> {
-        debug_assert!(parts.next().is_none());
-        Ok(())
-    }
-
-    fn parse_response(
-        parts: ResponseAttributes<'_>,
-    ) -> Result<Self::Response, ResponseParserError<'_>> {
-        debug_assert!(parts.is_empty());
-        Ok(())
-    }
+impl Command<'_, '_> for Close {
+    type Request = CloseRequest;
+    type Response = CloseResponse;
 }

src/commands/connection_settings/kill.rs

@@ -1,29 +1,19 @@
 use crate::{
-    commands::{Command, RequestParserError, ResponseParserError},
+    commands::{
+        Command, RequestParserError, ResponseParserError, empty_command_request,
+        empty_command_response,
+    },
     request_tokenizer::RequestTokenizer,
     response_tokenizer::ResponseAttributes,
 };
 
 pub struct Kill;
 
-impl Command for Kill {
-    type Request = ();
-    type Response = ();
-    const COMMAND: &'static str = "kill";
+empty_command_request!(Kill, "kill");
 
-    fn serialize_request(&self, _request: Self::Request) -> String {
-        Self::COMMAND.to_string()
-    }
+empty_command_response!(Kill);
 
-    fn parse_request(mut parts: RequestTokenizer<'_>) -> Result<Self::Request, RequestParserError> {
-        debug_assert!(parts.next().is_none());
-        Ok(())
-    }
-
-    fn parse_response(
-        parts: ResponseAttributes<'_>,
-    ) -> Result<Self::Response, ResponseParserError<'_>> {
-        debug_assert!(parts.is_empty());
-        Ok(())
-    }
+impl Command<'_, '_> for Kill {
+    type Request = KillRequest;
+    type Response = KillResponse;
 }

src/commands/connection_settings/password.rs

@@ -1,33 +1,19 @@
 use crate::{
-    commands::{Command, RequestParserError, ResponseParserError},
+    commands::{
+        Command, RequestParserError, ResponseParserError, empty_command_request,
+        empty_command_response, single_item_command_request,
+    },
     request_tokenizer::RequestTokenizer,
     response_tokenizer::ResponseAttributes,
 };
 
 pub struct Password;
 
-impl Command for Password {
-    type Request = String;
-    type Response = ();
-    const COMMAND: &'static str = "password";
+single_item_command_request!(Password, "password", String);
 
-    fn serialize_request(&self, request: Self::Request) -> String {
-        format!("{} {}", Self::COMMAND, request)
-    }
+empty_command_response!(Password);
 
-    fn parse_request(mut parts: RequestTokenizer<'_>) -> Result<Self::Request, RequestParserError> {
-        let password = parts
-            .next()
-            .ok_or(RequestParserError::UnexpectedEOF)?
-            .to_string();
-        debug_assert!(parts.next().is_none());
-        Ok(password)
-    }
-
-    fn parse_response(
-        parts: ResponseAttributes<'_>,
-    ) -> Result<Self::Response, ResponseParserError<'_>> {
-        debug_assert!(parts.is_empty());
-        Ok(())
-    }
+impl Command<'_, '_> for Password {
+    type Request = PasswordRequest;
+    type Response = PasswordResponse;
 }

src/commands/connection_settings/ping.rs

@@ -1,29 +1,19 @@
 use crate::{
-    commands::{Command, RequestParserError, ResponseParserError},
+    commands::{
+        Command, RequestParserError, ResponseParserError, empty_command_request,
+        empty_command_response,
+    },
     request_tokenizer::RequestTokenizer,
     response_tokenizer::ResponseAttributes,
 };
 
 pub struct Ping;
 
-impl Command for Ping {
-    type Request = ();
-    type Response = ();
-    const COMMAND: &'static str = "ping";
+empty_command_request!(Ping, "ping");
 
-    fn serialize_request(&self, _request: Self::Request) -> String {
-        Self::COMMAND.to_string()
-    }
+empty_command_response!(Ping);
 
-    fn parse_request(mut parts: RequestTokenizer<'_>) -> Result<Self::Request, RequestParserError> {
-        debug_assert!(parts.next().is_none());
-        Ok(())
-    }
-
-    fn parse_response(
-        parts: ResponseAttributes<'_>,
-    ) -> Result<Self::Response, ResponseParserError<'_>> {
-        debug_assert!(parts.is_empty());
-        Ok(())
-    }
+impl Command<'_, '_> for Ping {
+    type Request = PingRequest;
+    type Response = PingResponse;
 }

src/commands/connection_settings/protocol.rs

@@ -1,40 +1,19 @@
 use crate::{
-    commands::{Command, RequestParserError, ResponseParserError},
+    commands::{
+        Command, CommandResponse, RequestParserError, ResponseParserError, empty_command_request,
+        multi_item_command_response,
+    },
     request_tokenizer::RequestTokenizer,
     response_tokenizer::{ResponseAttributes, expect_property_type},
 };
 
 pub struct Protocol;
 
-pub type ProtocolResponse = Vec<String>;
+empty_command_request!(Protocol, "protocol");
 
-impl Command for Protocol {
-    type Request = ();
+multi_item_command_response!(Protocol, "feature", String);
+
+impl Command<'_, '_> for Protocol {
+    type Request = ProtocolRequest;
     type Response = ProtocolResponse;
-    const COMMAND: &'static str = "protocol";
-
-    fn serialize_request(&self, _request: Self::Request) -> String {
-        Self::COMMAND.to_string()
-    }
-
-    fn parse_request(mut parts: RequestTokenizer<'_>) -> Result<Self::Request, RequestParserError> {
-        debug_assert!(parts.next().is_none());
-        Ok(())
-    }
-
-    fn parse_response(
-        parts: ResponseAttributes<'_>,
-    ) -> Result<Self::Response, ResponseParserError<'_>> {
-        let parts_: Vec<_> = parts.into_vec()?;
-        if let Some((k, _)) = parts_.iter().find(|(k, _)| *k != "feature") {
-            return Err(ResponseParserError::UnexpectedProperty(k));
-        }
-
-        let list = parts_
-            .into_iter()
-            .map(|(k, v)| Ok(expect_property_type!(Some(v), k, Text).to_string()))
-            .collect::<Result<Vec<_>, ResponseParserError>>()?;
-
-        Ok(list)
-    }
 }

src/commands/connection_settings/protocol_all.rs

@@ -1,29 +1,19 @@
 use crate::{
-    commands::{Command, RequestParserError, ResponseParserError},
+    commands::{
+        Command, RequestParserError, ResponseParserError, empty_command_request,
+        empty_command_response,
+    },
     request_tokenizer::RequestTokenizer,
     response_tokenizer::ResponseAttributes,
 };
 
 pub struct ProtocolAll;
 
-impl Command for ProtocolAll {
-    type Request = ();
-    type Response = ();
-    const COMMAND: &'static str = "protocol all";
+empty_command_request!(ProtocolAll, "protocol all");
 
-    fn serialize_request(&self, _request: Self::Request) -> String {
-        Self::COMMAND.to_string()
-    }
+empty_command_response!(ProtocolAll);
 
-    fn parse_request(mut parts: RequestTokenizer<'_>) -> Result<Self::Request, RequestParserError> {
-        debug_assert!(parts.next().is_none());
-        Ok(())
-    }
-
-    fn parse_response(
-        parts: ResponseAttributes<'_>,
-    ) -> Result<Self::Response, ResponseParserError<'_>> {
-        debug_assert!(parts.is_empty());
-        Ok(())
-    }
+impl Command<'_, '_> for ProtocolAll {
+    type Request = ProtocolAllRequest;
+    type Response = ProtocolAllResponse;
 }

src/commands/connection_settings/protocol_available.rs

@@ -1,40 +1,19 @@
 use crate::{
-    commands::{Command, RequestParserError, ResponseParserError},
+    commands::{
+        Command, RequestParserError, ResponseParserError, empty_command_request,
+        multi_item_command_response,
+    },
     request_tokenizer::RequestTokenizer,
     response_tokenizer::{ResponseAttributes, expect_property_type},
 };
 
 pub struct ProtocolAvailable;
 
-pub type ProtocolAvailableResponse = Vec<String>;
+empty_command_request!(ProtocolAvailable, "protocol available");
 
-impl Command for ProtocolAvailable {
-    type Request = ();
+multi_item_command_response!(ProtocolAvailable, "feature", String);
+
+impl Command<'_, '_> for ProtocolAvailable {
+    type Request = ProtocolAvailableRequest;
     type Response = ProtocolAvailableResponse;
-    const COMMAND: &'static str = "protocol available";
-
-    fn serialize_request(&self, _request: Self::Request) -> String {
-        Self::COMMAND.to_string()
-    }
-
-    fn parse_request(mut parts: RequestTokenizer<'_>) -> Result<Self::Request, RequestParserError> {
-        debug_assert!(parts.next().is_none());
-        Ok(())
-    }
-
-    fn parse_response(
-        parts: ResponseAttributes<'_>,
-    ) -> Result<Self::Response, ResponseParserError<'_>> {
-        let parts_: Vec<_> = parts.into_vec()?;
-        if let Some((k, _)) = parts_.iter().find(|(k, _)| *k != "feature") {
-            return Err(ResponseParserError::UnexpectedProperty(k));
-        }
-
-        let list = parts_
-            .into_iter()
-            .map(|(k, v)| Ok(expect_property_type!(Some(v), k, Text).to_string()))
-            .collect::<Result<Vec<_>, ResponseParserError>>()?;
-
-        Ok(list)
-    }
 }

src/commands/connection_settings/protocol_clear.rs

@@ -1,29 +1,19 @@
 use crate::{
-    commands::{Command, RequestParserError, ResponseParserError},
+    commands::{
+        Command, RequestParserError, ResponseParserError, empty_command_request,
+        empty_command_response,
+    },
     request_tokenizer::RequestTokenizer,
     response_tokenizer::ResponseAttributes,
 };
 
 pub struct ProtocolClear;
 
-impl Command for ProtocolClear {
-    type Request = ();
-    type Response = ();
-    const COMMAND: &'static str = "protocol clear";
+empty_command_request!(ProtocolClear, "protocol clear");
 
-    fn serialize_request(&self, _request: Self::Request) -> String {
-        Self::COMMAND.to_string()
-    }
+empty_command_response!(ProtocolClear);
 
-    fn parse_request(mut parts: RequestTokenizer<'_>) -> Result<Self::Request, RequestParserError> {
-        debug_assert!(parts.next().is_none());
-        Ok(())
-    }
-
-    fn parse_response(
-        parts: ResponseAttributes<'_>,
-    ) -> Result<Self::Response, ResponseParserError<'_>> {
-        debug_assert!(parts.is_empty());
-        Ok(())
-    }
+impl Command<'_, '_> for ProtocolClear {
+    type Request = ProtocolClearRequest;
+    type Response = ProtocolClearResponse;
 }

src/commands/connection_settings/protocol_disable.rs

@@ -1,5 +1,7 @@
 use crate::{
-    commands::{Command, RequestParserError, ResponseParserError},
+    commands::{
+        Command, CommandRequest, RequestParserError, ResponseParserError, empty_command_response,
+    },
     common::types::Feature,
     request_tokenizer::RequestTokenizer,
     response_tokenizer::ResponseAttributes,
@@ -7,32 +9,53 @@ use crate::{
 
 pub struct ProtocolDisable;
 
-pub type ProtocolDisableRequest = Vec<Feature>;
+pub struct ProtocolDisableRequest(Vec<Feature>);
 
-impl Command for ProtocolDisable {
-    type Request = ProtocolDisableRequest;
-    type Response = ();
+impl CommandRequest<'_> for ProtocolDisableRequest {
     const COMMAND: &'static str = "protocol disable";
 
-    fn serialize_request(&self, request: Self::Request) -> String {
-        format!("{} {}", Self::COMMAND, request.join(" "))
+    fn into_request_enum(self) -> crate::Request {
+        crate::Request::ProtocolDisable(self.0)
     }
 
-    fn parse_request(parts: RequestTokenizer<'_>) -> Result<Self::Request, RequestParserError> {
+    fn from_request_enum(request: crate::Request) -> Option<Self> {
+        match request {
+            crate::Request::ProtocolDisable(features) => Some(ProtocolDisableRequest(features)),
+            _ => None,
+        }
+    }
+
+    fn serialize(&self) -> String {
+        let features = self
+            .0
+            .iter()
+            .map(|f| f.to_string())
+            .collect::<Vec<String>>()
+            .join(" ");
+        format!("{} {}", Self::COMMAND, features)
+    }
+
+    fn parse(parts: RequestTokenizer<'_>) -> Result<Self, RequestParserError> {
         let mut parts = parts.peekable();
         if parts.peek().is_none() {
             return Err(RequestParserError::UnexpectedEOF);
         }
 
-        let features = parts.map(|s| s.to_string()).collect::<Vec<String>>();
+        let mut features = Vec::new();
+        for part in parts {
+            let feature = part
+                .parse()
+                .map_err(|_| RequestParserError::SyntaxError(1, part.to_owned()))?;
+            features.push(feature);
+        }
 
-        Ok(features)
-    }
-
-    fn parse_response(
-        parts: ResponseAttributes<'_>,
-    ) -> Result<Self::Response, ResponseParserError<'_>> {
-        debug_assert!(parts.is_empty());
-        Ok(())
+        Ok(ProtocolDisableRequest(features))
     }
 }
+
+empty_command_response!(ProtocolDisable);
+
+impl Command<'_, '_> for ProtocolDisable {
+    type Request = ProtocolDisableRequest;
+    type Response = ProtocolDisableResponse;
+}

src/commands/connection_settings/protocol_enable.rs

@@ -1,5 +1,7 @@
 use crate::{
-    commands::{Command, RequestParserError, ResponseParserError},
+    commands::{
+        Command, CommandRequest, RequestParserError, ResponseParserError, empty_command_response,
+    },
     common::types::Feature,
     request_tokenizer::RequestTokenizer,
     response_tokenizer::ResponseAttributes,
@@ -7,32 +9,53 @@ use crate::{
 
 pub struct ProtocolEnable;
 
-pub type ProtocolEnableRequest = Vec<Feature>;
+pub struct ProtocolEnableRequest(Vec<Feature>);
 
-impl Command for ProtocolEnable {
-    type Request = ProtocolEnableRequest;
-    type Response = ();
+impl CommandRequest<'_> for ProtocolEnableRequest {
     const COMMAND: &'static str = "protocol enable";
 
-    fn serialize_request(&self, request: Self::Request) -> String {
-        format!("{} {}", Self::COMMAND, request.join(" "))
+    fn into_request_enum(self) -> crate::Request {
+        crate::Request::ProtocolEnable(self.0)
     }
 
-    fn parse_request(parts: RequestTokenizer<'_>) -> Result<Self::Request, RequestParserError> {
+    fn from_request_enum(request: crate::Request) -> Option<Self> {
+        match request {
+            crate::Request::ProtocolEnable(features) => Some(ProtocolEnableRequest(features)),
+            _ => None,
+        }
+    }
+
+    fn serialize(&self) -> String {
+        let features = self
+            .0
+            .iter()
+            .map(|f| f.to_string())
+            .collect::<Vec<String>>()
+            .join(" ");
+        format!("{} {}", Self::COMMAND, features)
+    }
+
+    fn parse(parts: RequestTokenizer<'_>) -> Result<Self, RequestParserError> {
         let mut parts = parts.peekable();
         if parts.peek().is_none() {
             return Err(RequestParserError::UnexpectedEOF);
         }
 
-        let features = parts.map(|s| s.to_string()).collect::<Vec<String>>();
+        let mut features = Vec::new();
+        for part in parts {
+            let feature = part
+                .parse()
+                .map_err(|_| RequestParserError::SyntaxError(1, part.to_owned()))?;
+            features.push(feature);
+        }
 
-        Ok(features)
-    }
-
-    fn parse_response(
-        parts: ResponseAttributes<'_>,
-    ) -> Result<Self::Response, ResponseParserError<'_>> {
-        debug_assert!(parts.is_empty());
-        Ok(())
+        Ok(ProtocolEnableRequest(features))
     }
 }
+
+empty_command_response!(ProtocolEnable);
+
+impl Command<'_, '_> for ProtocolEnable {
+    type Request = ProtocolEnableRequest;
+    type Response = ProtocolEnableResponse;
+}

src/commands/connection_settings/tag_types.rs

@@ -1,43 +1,19 @@
 use crate::{
-    commands::{Command, RequestParserError, ResponseParserError},
+    commands::{
+        Command, RequestParserError, ResponseParserError, empty_command_request,
+        multi_item_command_response,
+    },
     request_tokenizer::RequestTokenizer,
     response_tokenizer::{ResponseAttributes, expect_property_type},
 };
 
 pub struct TagTypes;
 
-pub type TagTypesResponse = Vec<String>;
+empty_command_request!(TagTypes, "tagtypes");
 
-impl Command for TagTypes {
-    type Request = ();
+multi_item_command_response!(TagTypes, "tagtype", String);
+
+impl Command<'_, '_> for TagTypes {
+    type Request = TagTypesRequest;
     type Response = TagTypesResponse;
-    const COMMAND: &'static str = "tagtypes";
-
-    fn serialize_request(&self, _request: Self::Request) -> String {
-        Self::COMMAND.to_string()
-    }
-
-    fn parse_request(mut parts: RequestTokenizer<'_>) -> Result<Self::Request, RequestParserError> {
-        debug_assert!(parts.next().is_none());
-        Ok(())
-    }
-
-    fn parse_response(
-        parts: ResponseAttributes<'_>,
-    ) -> Result<Self::Response, ResponseParserError<'_>> {
-        let parts: Vec<_> = parts.into_vec()?;
-
-        let mut tagtypes = Vec::with_capacity(parts.len());
-        for (key, value) in parts.into_iter() {
-            if key != "tagtype" {
-                return Err(ResponseParserError::UnexpectedProperty(key));
-            }
-
-            let tagtype = expect_property_type!(Some(value), "tagtype", Text).to_string();
-
-            tagtypes.push(tagtype);
-        }
-
-        Ok(tagtypes)
-    }
 }

src/commands/connection_settings/tag_types_all.rs

@@ -1,29 +1,19 @@
 use crate::{
-    commands::{Command, RequestParserError, ResponseParserError},
+    commands::{
+        Command, RequestParserError, ResponseParserError, empty_command_request,
+        empty_command_response,
+    },
     request_tokenizer::RequestTokenizer,
     response_tokenizer::ResponseAttributes,
 };
 
 pub struct TagTypesAll;
 
-impl Command for TagTypesAll {
-    type Request = ();
-    type Response = ();
-    const COMMAND: &'static str = "tagtypes all";
+empty_command_request!(TagTypesAll, "tagtypes all");
 
-    fn serialize_request(&self, _request: Self::Request) -> String {
-        Self::COMMAND.to_string()
-    }
+empty_command_response!(TagTypesAll);
 
-    fn parse_request(mut parts: RequestTokenizer<'_>) -> Result<Self::Request, RequestParserError> {
-        debug_assert!(parts.next().is_none());
-        Ok(())
-    }
-
-    fn parse_response(
-        parts: ResponseAttributes<'_>,
-    ) -> Result<Self::Response, ResponseParserError<'_>> {
-        debug_assert!(parts.is_empty());
-        Ok(())
-    }
+impl Command<'_, '_> for TagTypesAll {
+    type Request = TagTypesAllRequest;
+    type Response = TagTypesAllResponse;
 }

src/commands/connection_settings/tag_types_available.rs

@@ -1,43 +1,19 @@
 use crate::{
-    commands::{Command, RequestParserError, ResponseParserError},
+    commands::{
+        Command, RequestParserError, ResponseParserError, empty_command_request,
+        multi_item_command_response,
+    },
     request_tokenizer::RequestTokenizer,
     response_tokenizer::{ResponseAttributes, expect_property_type},
 };
 
 pub struct TagTypesAvailable;
 
-pub type TagTypesAvailableResponse = Vec<String>;
+empty_command_request!(TagTypesAvailable, "tagtypes available");
 
-impl Command for TagTypesAvailable {
-    type Request = ();
+multi_item_command_response!(TagTypesAvailable, "tagtype", String);
+
+impl Command<'_, '_> for TagTypesAvailable {
+    type Request = TagTypesAvailableRequest;
     type Response = TagTypesAvailableResponse;
-    const COMMAND: &'static str = "tagtypes available";
-
-    fn serialize_request(&self, _request: Self::Request) -> String {
-        Self::COMMAND.to_string()
-    }
-
-    fn parse_request(mut parts: RequestTokenizer<'_>) -> Result<Self::Request, RequestParserError> {
-        debug_assert!(parts.next().is_none());
-        Ok(())
-    }
-
-    fn parse_response(
-        parts: ResponseAttributes<'_>,
-    ) -> Result<Self::Response, ResponseParserError<'_>> {
-        let parts: Vec<_> = parts.into_vec()?;
-
-        let mut tagtypes = Vec::with_capacity(parts.len());
-        for (key, value) in parts.into_iter() {
-            if key != "tagtype" {
-                return Err(ResponseParserError::UnexpectedProperty(key));
-            }
-
-            let tagtype = expect_property_type!(Some(value), "tagtype", Text).to_string();
-
-            tagtypes.push(tagtype);
-        }
-
-        Ok(tagtypes)
-    }
 }

src/commands/connection_settings/tag_types_clear.rs

@@ -1,29 +1,19 @@
 use crate::{
-    commands::{Command, RequestParserError, ResponseParserError},
+    commands::{
+        Command, RequestParserError, ResponseParserError, empty_command_request,
+        empty_command_response,
+    },
     request_tokenizer::RequestTokenizer,
     response_tokenizer::ResponseAttributes,
 };
 
 pub struct TagTypesClear;
 
-impl Command for TagTypesClear {
-    type Request = ();
-    type Response = ();
-    const COMMAND: &'static str = "tagtypes clear";
+empty_command_request!(TagTypesClear, "tagtypes clear");
 
-    fn serialize_request(&self, _request: Self::Request) -> String {
-        Self::COMMAND.to_string()
-    }
+empty_command_response!(TagTypesClear);
 
-    fn parse_request(mut parts: RequestTokenizer<'_>) -> Result<Self::Request, RequestParserError> {
-        debug_assert!(parts.next().is_none());
-        Ok(())
-    }
-
-    fn parse_response(
-        parts: ResponseAttributes<'_>,
-    ) -> Result<Self::Response, ResponseParserError<'_>> {
-        debug_assert!(parts.is_empty());
-        Ok(())
-    }
+impl Command<'_, '_> for TagTypesClear {
+    type Request = TagTypesClearRequest;
+    type Response = TagTypesClearResponse;
 }

src/commands/connection_settings/tag_types_disable.rs

@@ -1,5 +1,7 @@
 use crate::{
-    commands::{Command, RequestParserError, ResponseParserError},
+    commands::{
+        Command, CommandRequest, RequestParserError, ResponseParserError, empty_command_response,
+    },
     common::types::TagName,
     request_tokenizer::RequestTokenizer,
     response_tokenizer::ResponseAttributes,
@@ -7,32 +9,54 @@ use crate::{
 
 pub struct TagTypesDisable;
 
-pub type TagTypesDisableRequest = Vec<TagName>;
+pub struct TagTypesDisableRequest(Vec<TagName>);
 
-impl Command for TagTypesDisable {
-    type Request = TagTypesDisableRequest;
-    type Response = ();
+impl CommandRequest<'_> for TagTypesDisableRequest {
     const COMMAND: &'static str = "tagtypes disable";
 
-    fn serialize_request(&self, request: Self::Request) -> String {
-        format!("{} {}", Self::COMMAND, request.join(" "))
+    fn into_request_enum(self) -> crate::Request {
+        crate::Request::TagTypesDisable(self.0)
     }
 
-    fn parse_request(parts: RequestTokenizer<'_>) -> Result<Self::Request, RequestParserError> {
+    fn from_request_enum(request: crate::Request) -> Option<Self> {
+        match request {
+            crate::Request::TagTypesDisable(req) => Some(TagTypesDisableRequest(req)),
+            _ => None,
+        }
+    }
+
+    fn serialize(&self) -> String {
+        format!(
+            "{} {}",
+            Self::COMMAND,
+            self.0
+                .iter()
+                .map(|tag| tag.as_str())
+                .collect::<Vec<&str>>()
+                .join(" ")
+        )
+    }
+
+    fn parse(parts: RequestTokenizer<'_>) -> Result<Self, RequestParserError> {
         let mut parts = parts.peekable();
         if parts.peek().is_none() {
             return Err(RequestParserError::UnexpectedEOF);
         }
 
-        let tag_types = parts.map(|s| s.to_string()).collect::<Vec<String>>();
+        let tag_types = parts
+            .map(|s| {
+                s.parse()
+                    .map_err(|_| RequestParserError::SyntaxError(1, s.to_owned()))
+            })
+            .collect::<Result<Vec<TagName>, RequestParserError>>()?;
 
-        Ok(tag_types)
-    }
-
-    fn parse_response(
-        parts: ResponseAttributes<'_>,
-    ) -> Result<Self::Response, ResponseParserError<'_>> {
-        debug_assert!(parts.is_empty());
-        Ok(())
+        Ok(TagTypesDisableRequest(tag_types))
     }
 }
+
+empty_command_response!(TagTypesDisable);
+
+impl Command<'_, '_> for TagTypesDisable {
+    type Request = TagTypesDisableRequest;
+    type Response = TagTypesDisableResponse;
+}

src/commands/connection_settings/tag_types_enable.rs

@@ -1,5 +1,7 @@
 use crate::{
-    commands::{Command, RequestParserError, ResponseParserError},
+    commands::{
+        Command, CommandRequest, RequestParserError, ResponseParserError, empty_command_response,
+    },
     common::types::TagName,
     request_tokenizer::RequestTokenizer,
     response_tokenizer::ResponseAttributes,
@@ -7,32 +9,54 @@ use crate::{
 
 pub struct TagTypesEnable;
 
-pub type TagTypesEnableRequest = Vec<TagName>;
+pub struct TagTypesEnableRequest(Vec<TagName>);
 
-impl Command for TagTypesEnable {
-    type Request = TagTypesEnableRequest;
-    type Response = ();
+impl CommandRequest<'_> for TagTypesEnableRequest {
     const COMMAND: &'static str = "tagtypes enable";
 
-    fn serialize_request(&self, request: Self::Request) -> String {
-        format!("{} {}", Self::COMMAND, request.join(" "))
+    fn into_request_enum(self) -> crate::Request {
+        crate::Request::TagTypesEnable(self.0)
     }
 
-    fn parse_request(parts: RequestTokenizer<'_>) -> Result<Self::Request, RequestParserError> {
+    fn from_request_enum(request: crate::Request) -> Option<Self> {
+        match request {
+            crate::Request::TagTypesEnable(req) => Some(TagTypesEnableRequest(req)),
+            _ => None,
+        }
+    }
+
+    fn serialize(&self) -> String {
+        format!(
+            "{} {}",
+            Self::COMMAND,
+            self.0
+                .iter()
+                .map(|tag| tag.as_str())
+                .collect::<Vec<&str>>()
+                .join(" ")
+        )
+    }
+
+    fn parse(parts: RequestTokenizer<'_>) -> Result<Self, RequestParserError> {
         let mut parts = parts.peekable();
         if parts.peek().is_none() {
             return Err(RequestParserError::UnexpectedEOF);
         }
 
-        let tag_types = parts.map(|s| s.to_string()).collect::<Vec<String>>();
+        let tag_types = parts
+            .map(|s| {
+                s.parse()
+                    .map_err(|_| RequestParserError::SyntaxError(1, s.to_owned()))
+            })
+            .collect::<Result<Vec<TagName>, RequestParserError>>()?;
 
-        Ok(tag_types)
-    }
-
-    fn parse_response(
-        parts: ResponseAttributes<'_>,
-    ) -> Result<Self::Response, ResponseParserError<'_>> {
-        debug_assert!(parts.is_empty());
-        Ok(())
+        Ok(TagTypesEnableRequest(tag_types))
     }
 }
+
+empty_command_response!(TagTypesEnable);
+
+impl Command<'_, '_> for TagTypesEnable {
+    type Request = TagTypesEnableRequest;
+    type Response = TagTypesEnableResponse;
+}

src/commands/connection_settings/tag_types_reset.rs

@@ -1,5 +1,7 @@
 use crate::{
-    commands::{Command, RequestParserError, ResponseParserError},
+    commands::{
+        Command, CommandRequest, RequestParserError, ResponseParserError, empty_command_response,
+    },
     common::types::TagName,
     request_tokenizer::RequestTokenizer,
     response_tokenizer::ResponseAttributes,
@@ -7,33 +9,54 @@ use crate::{
 
 pub struct TagTypesReset;
 
-pub type TagTypesResetRequest = Vec<TagName>;
+pub struct TagTypesResetRequest(Vec<TagName>);
 
-impl Command for TagTypesReset {
-    type Request = TagTypesResetRequest;
-    type Response = ();
+impl CommandRequest<'_> for TagTypesResetRequest {
     const COMMAND: &'static str = "tagtypes reset";
 
-    fn serialize_request(&self, request: Self::Request) -> String {
-        format!("{} {}", Self::COMMAND, request.join(" "))
+    fn into_request_enum(self) -> crate::Request {
+        crate::Request::TagTypesReset(self.0)
     }
 
-    fn parse_request(parts: RequestTokenizer<'_>) -> Result<Self::Request, RequestParserError> {
+    fn from_request_enum(request: crate::Request) -> Option<Self> {
+        match request {
+            crate::Request::TagTypesReset(req) => Some(TagTypesResetRequest(req)),
+            _ => None,
+        }
+    }
+
+    fn serialize(&self) -> String {
+        format!(
+            "{} {}",
+            Self::COMMAND,
+            self.0
+                .iter()
+                .map(|tag| tag.as_str())
+                .collect::<Vec<&str>>()
+                .join(" ")
+        )
+    }
+
+    fn parse(parts: RequestTokenizer<'_>) -> Result<Self, RequestParserError> {
         let mut parts = parts.peekable();
         if parts.peek().is_none() {
             return Err(RequestParserError::UnexpectedEOF);
         }
 
-        // TODO: verify that the tag types are split by whitespace
-        let tag_types = parts.map(|s| s.to_string()).collect::<Vec<String>>();
+        let tag_types = parts
+            .map(|s| {
+                s.parse()
+                    .map_err(|_| RequestParserError::SyntaxError(1, s.to_owned()))
+            })
+            .collect::<Result<Vec<TagName>, RequestParserError>>()?;
 
-        Ok(tag_types)
-    }
-
-    fn parse_response(
-        parts: ResponseAttributes<'_>,
-    ) -> Result<Self::Response, ResponseParserError<'_>> {
-        debug_assert!(parts.is_empty());
-        Ok(())
+        Ok(TagTypesResetRequest(tag_types))
     }
 }
+
+empty_command_response!(TagTypesReset);
+
+impl Command<'_, '_> for TagTypesReset {
+    type Request = TagTypesResetRequest;
+    type Response = TagTypesResetResponse;
+}

src/commands/controlling_playback/next.rs

@@ -1,29 +1,19 @@
 use crate::{
-    commands::{Command, RequestParserError, ResponseParserError},
+    commands::{
+        Command, RequestParserError, ResponseParserError, empty_command_request,
+        empty_command_response,
+    },
     request_tokenizer::RequestTokenizer,
     response_tokenizer::ResponseAttributes,
 };
 
 pub struct Next;
 
-impl Command for Next {
-    type Request = ();
-    type Response = ();
-    const COMMAND: &'static str = "next";
+empty_command_request!(Next, "next");
 
-    fn serialize_request(&self, _request: Self::Request) -> String {
-        Self::COMMAND.to_string()
-    }
+empty_command_response!(Next);
 
-    fn parse_request(mut parts: RequestTokenizer<'_>) -> Result<Self::Request, RequestParserError> {
-        debug_assert!(parts.next().is_none());
-        Ok(())
-    }
-
-    fn parse_response(
-        parts: ResponseAttributes<'_>,
-    ) -> Result<Self::Response, ResponseParserError<'_>> {
-        debug_assert!(parts.is_empty());
-        Ok(())
-    }
+impl Command<'_, '_> for Next {
+    type Request = NextRequest;
+    type Response = NextResponse;
 }

src/commands/controlling_playback/pause.rs

@@ -1,25 +1,38 @@
 use crate::{
-    commands::{Command, RequestParserError, ResponseParserError},
+    commands::{
+        Command, CommandRequest, RequestParserError, ResponseParserError, empty_command_response,
+    },
     request_tokenizer::RequestTokenizer,
     response_tokenizer::ResponseAttributes,
 };
 
 pub struct Pause;
 
-impl Command for Pause {
-    type Request = Option<bool>;
-    type Response = ();
+pub struct PauseRequest(Option<bool>);
+
+impl CommandRequest<'_> for PauseRequest {
     const COMMAND: &'static str = "pause";
 
-    fn serialize_request(&self, request: Self::Request) -> String {
+    fn into_request_enum(self) -> crate::Request {
+        crate::Request::Pause(self.0)
+    }
+
+    fn from_request_enum(request: crate::Request) -> Option<Self> {
         match request {
+            crate::Request::Pause(value) => Some(PauseRequest(value)),
+            _ => None,
+        }
+    }
+
+    fn serialize(&self) -> String {
+        match self.0 {
             Some(true) => format!("{} 1", Self::COMMAND),
             Some(false) => format!("{} 0", Self::COMMAND),
             None => Self::COMMAND.to_string(),
         }
     }
 
-    fn parse_request(mut parts: RequestTokenizer<'_>) -> Result<Self::Request, RequestParserError> {
+    fn parse(mut parts: RequestTokenizer<'_>) -> Result<Self, RequestParserError> {
         let result = match parts.next() {
             Some("0") => Ok(Some(false)),
             Some("1") => Ok(Some(true)),
@@ -29,13 +42,13 @@ impl Command for Pause {
 
         debug_assert!(parts.next().is_none());
 
-        result
-    }
-
-    fn parse_response(
-        parts: ResponseAttributes<'_>,
-    ) -> Result<Self::Response, ResponseParserError<'_>> {
-        debug_assert!(parts.is_empty());
-        Ok(())
+        result.map(PauseRequest)
     }
 }
+
+empty_command_response!(Pause);
+
+impl Command<'_, '_> for Pause {
+    type Request = PauseRequest;
+    type Response = PauseResponse;
+}

src/commands/controlling_playback/play.rs

@@ -1,5 +1,8 @@
 use crate::{
-    commands::{Command, RequestParserError, ResponseParserError},
+    commands::{
+        Command, RequestParserError, ResponseParserError, empty_command_response,
+        single_item_command_request,
+    },
     common::types::SongPosition,
     request_tokenizer::RequestTokenizer,
     response_tokenizer::ResponseAttributes,
@@ -7,32 +10,11 @@ use crate::{
 
 pub struct Play;
 
-impl Command for Play {
-    type Request = SongPosition;
-    type Response = ();
-    const COMMAND: &'static str = "play";
+single_item_command_request!(Play, "play", SongPosition);
 
-    fn serialize_request(&self, request: Self::Request) -> String {
-        format!("{} {}", Self::COMMAND, request)
-    }
+empty_command_response!(Play);
 
-    fn parse_request(mut parts: RequestTokenizer<'_>) -> Result<Self::Request, RequestParserError> {
-        let songpos = match parts.next() {
-            Some(s) => s
-                .parse::<SongPosition>()
-                .map_err(|_| RequestParserError::SyntaxError(0, s.to_owned()))?,
-            None => return Err(RequestParserError::UnexpectedEOF),
-        };
-
-        debug_assert!(parts.next().is_none());
-
-        Ok(songpos)
-    }
-
-    fn parse_response(
-        parts: ResponseAttributes<'_>,
-    ) -> Result<Self::Response, ResponseParserError<'_>> {
-        debug_assert!(parts.is_empty());
-        Ok(())
-    }
+impl Command<'_, '_> for Play {
+    type Request = PlayRequest;
+    type Response = PlayResponse;
 }

src/commands/controlling_playback/playid.rs

@@ -1,5 +1,8 @@
 use crate::{
-    commands::{Command, RequestParserError, ResponseParserError},
+    commands::{
+        Command, RequestParserError, ResponseParserError, empty_command_request,
+        empty_command_response, single_item_command_request,
+    },
     common::types::SongId,
     request_tokenizer::RequestTokenizer,
     response_tokenizer::ResponseAttributes,
@@ -7,32 +10,11 @@ use crate::{
 
 pub struct PlayId;
 
-impl Command for PlayId {
-    type Request = SongId;
-    type Response = ();
-    const COMMAND: &'static str = "playid";
+single_item_command_request!(PlayId, "playid", SongId);
 
-    fn serialize_request(&self, request: Self::Request) -> String {
-        format!("{} {}", Self::COMMAND, request)
-    }
+empty_command_response!(PlayId);
 
-    fn parse_request(mut parts: RequestTokenizer<'_>) -> Result<Self::Request, RequestParserError> {
-        let songid = match parts.next() {
-            Some(s) => s
-                .parse::<SongId>()
-                .map_err(|_| RequestParserError::SyntaxError(0, s.to_owned()))?,
-            None => return Err(RequestParserError::UnexpectedEOF),
-        };
-
-        debug_assert!(parts.next().is_none());
-
-        Ok(songid)
-    }
-
-    fn parse_response(
-        parts: ResponseAttributes<'_>,
-    ) -> Result<Self::Response, ResponseParserError<'_>> {
-        debug_assert!(parts.is_empty());
-        Ok(())
-    }
+impl Command<'_, '_> for PlayId {
+    type Request = PlayIdRequest;
+    type Response = PlayIdResponse;
 }

src/commands/controlling_playback/previous.rs

@@ -1,29 +1,19 @@
 use crate::{
-    commands::{Command, RequestParserError, ResponseParserError},
+    commands::{
+        Command, RequestParserError, ResponseParserError, empty_command_request,
+        empty_command_response,
+    },
     request_tokenizer::RequestTokenizer,
     response_tokenizer::ResponseAttributes,
 };
 
 pub struct Previous;
 
-impl Command for Previous {
-    type Request = ();
-    type Response = ();
-    const COMMAND: &'static str = "previous";
+empty_command_request!(Previous, "previous");
 
-    fn serialize_request(&self, _request: Self::Request) -> String {
-        Self::COMMAND.to_string()
-    }
+empty_command_response!(Previous);
 
-    fn parse_request(mut parts: RequestTokenizer<'_>) -> Result<Self::Request, RequestParserError> {
-        debug_assert!(parts.next().is_none());
-        Ok(())
-    }
-
-    fn parse_response(
-        parts: ResponseAttributes<'_>,
-    ) -> Result<Self::Response, ResponseParserError<'_>> {
-        debug_assert!(parts.is_empty());
-        Ok(())
-    }
+impl Command<'_, '_> for Previous {
+    type Request = PreviousRequest;
+    type Response = PreviousResponse;
 }

src/commands/controlling_playback/seek.rs

@@ -1,7 +1,9 @@
 use serde::{Deserialize, Serialize};
 
 use crate::{
-    commands::{Command, RequestParserError, ResponseParserError},
+    commands::{
+        Command, CommandRequest, RequestParserError, ResponseParserError, empty_command_response,
+    },
     common::types::{SongPosition, TimeWithFractions},
     request_tokenizer::RequestTokenizer,
     response_tokenizer::ResponseAttributes,
@@ -15,16 +17,25 @@ pub struct SeekRequest {
     pub time: TimeWithFractions,
 }
 
-impl Command for Seek {
-    type Request = SeekRequest;
-    type Response = ();
+impl CommandRequest<'_> for SeekRequest {
     const COMMAND: &'static str = "seek";
 
-    fn serialize_request(&self, request: Self::Request) -> String {
-        format!("{} {} {}", Self::COMMAND, request.songpos, request.time)
+    fn into_request_enum(self) -> crate::Request {
+        crate::Request::Seek(self.songpos, self.time)
     }
 
-    fn parse_request(mut parts: RequestTokenizer<'_>) -> Result<Self::Request, RequestParserError> {
+    fn from_request_enum(request: crate::Request) -> Option<Self> {
+        match request {
+            crate::Request::Seek(songpos, time) => Some(SeekRequest { songpos, time }),
+            _ => None,
+        }
+    }
+
+    fn serialize(&self) -> String {
+        format!("{} {} {}", Self::COMMAND, self.songpos, self.time)
+    }
+
+    fn parse(mut parts: RequestTokenizer<'_>) -> Result<Self, RequestParserError> {
         let songpos = match parts.next() {
             Some(s) => s
                 .parse::<SongPosition>()
@@ -43,11 +54,11 @@ impl Command for Seek {
 
         Ok(SeekRequest { songpos, time })
     }
-
-    fn parse_response(
-        parts: ResponseAttributes<'_>,
-    ) -> Result<Self::Response, ResponseParserError<'_>> {
-        debug_assert!(parts.is_empty());
-        Ok(())
-    }
+}
+
+empty_command_response!(Seek);
+
+impl Command<'_, '_> for Seek {
+    type Request = SeekRequest;
+    type Response = SeekResponse;
 }

src/commands/controlling_playback/seekcur.rs

@@ -1,7 +1,10 @@
 use serde::{Deserialize, Serialize};
 
 use crate::{
-    commands::{Command, RequestParserError, ResponseAttributes, ResponseParserError},
+    commands::{
+        Command, CommandRequest, RequestParserError, ResponseAttributes, ResponseParserError,
+        empty_command_response,
+    },
     common::types::{SeekMode, TimeWithFractions},
     request_tokenizer::RequestTokenizer,
 };
@@ -14,23 +17,32 @@ pub struct SeekCurRequest {
     pub time: TimeWithFractions,
 }
 
-impl Command for SeekCur {
-    type Request = SeekCurRequest;
-    type Response = ();
+impl CommandRequest<'_> for SeekCurRequest {
     const COMMAND: &'static str = "seekcur";
 
-    fn serialize_request(&self, request: Self::Request) -> String {
-        let time_str = match request.mode {
-            SeekMode::Absolute => format!("{}", request.time),
-            SeekMode::Relative if request.time >= 0.0 => format!("+{}", request.time),
-            SeekMode::Relative => format!("-{}", -request.time),
+    fn into_request_enum(self) -> crate::Request {
+        crate::Request::SeekCur(self.mode, self.time)
+    }
+
+    fn from_request_enum(request: crate::Request) -> Option<Self> {
+        match request {
+            crate::Request::SeekCur(mode, time) => Some(SeekCurRequest { mode, time }),
+            _ => None,
+        }
+    }
+
+    fn serialize(&self) -> String {
+        let time_str = match self.mode {
+            SeekMode::Absolute => format!("{}", self.time),
+            SeekMode::Relative if self.time >= 0.0 => format!("+{}", self.time),
+            SeekMode::Relative => format!("-{}", -self.time),
             SeekMode::RelativeReverse => unimplemented!(), // TODO: should this happen?
         };
 
         format!("{} {}", Self::COMMAND, time_str)
     }
 
-    fn parse_request(mut parts: RequestTokenizer<'_>) -> Result<Self::Request, RequestParserError> {
+    fn parse(mut parts: RequestTokenizer<'_>) -> Result<Self, RequestParserError> {
         let time_raw = match parts.next() {
             Some(t) => t,
             None => return Err(RequestParserError::UnexpectedEOF),
@@ -61,11 +73,11 @@ impl Command for SeekCur {
 
         Ok(SeekCurRequest { mode, time })
     }
-
-    fn parse_response(
-        parts: ResponseAttributes<'_>,
-    ) -> Result<Self::Response, ResponseParserError<'_>> {
-        debug_assert!(parts.is_empty());
-        Ok(())
-    }
+}
+
+empty_command_response!(SeekCur);
+
+impl Command<'_, '_> for SeekCur {
+    type Request = SeekCurRequest;
+    type Response = SeekCurResponse;
 }

src/commands/controlling_playback/seekid.rs

@@ -1,7 +1,9 @@
 use serde::{Deserialize, Serialize};
 
 use crate::{
-    commands::{Command, RequestParserError, ResponseParserError},
+    commands::{
+        Command, CommandRequest, RequestParserError, ResponseParserError, empty_command_response,
+    },
     common::types::{SongId, TimeWithFractions},
     request_tokenizer::RequestTokenizer,
     response_tokenizer::ResponseAttributes,
@@ -15,16 +17,25 @@ pub struct SeekIdRequest {
     pub time: TimeWithFractions,
 }
 
-impl Command for SeekId {
-    type Request = SeekIdRequest;
-    type Response = ();
+impl CommandRequest<'_> for SeekIdRequest {
     const COMMAND: &'static str = "seekid";
 
-    fn serialize_request(&self, request: Self::Request) -> String {
-        format!("{} {} {}", Self::COMMAND, request.songid, request.time)
+    fn into_request_enum(self) -> crate::Request {
+        crate::Request::SeekId(self.songid, self.time)
     }
 
-    fn parse_request(mut parts: RequestTokenizer<'_>) -> Result<Self::Request, RequestParserError> {
+    fn from_request_enum(request: crate::Request) -> Option<Self> {
+        match request {
+            crate::Request::SeekId(songid, time) => Some(SeekIdRequest { songid, time }),
+            _ => None,
+        }
+    }
+
+    fn serialize(&self) -> String {
+        format!("{} {} {}", Self::COMMAND, self.songid, self.time)
+    }
+
+    fn parse(mut parts: RequestTokenizer<'_>) -> Result<Self, RequestParserError> {
         let songid = match parts.next() {
             Some(s) => s
                 .parse::<SongId>()
@@ -43,11 +54,11 @@ impl Command for SeekId {
 
         Ok(SeekIdRequest { songid, time })
     }
-
-    fn parse_response(
-        parts: ResponseAttributes<'_>,
-    ) -> Result<Self::Response, ResponseParserError<'_>> {
-        debug_assert!(parts.is_empty());
-        Ok(())
-    }
+}
+
+empty_command_response!(SeekId);
+
+impl Command<'_, '_> for SeekId {
+    type Request = SeekIdRequest;
+    type Response = SeekIdResponse;
 }

src/commands/controlling_playback/stop.rs

@@ -1,29 +1,19 @@
 use crate::{
-    commands::{Command, RequestParserError, ResponseParserError},
+    commands::{
+        Command, RequestParserError, ResponseParserError, empty_command_request,
+        empty_command_response,
+    },
     request_tokenizer::RequestTokenizer,
     response_tokenizer::ResponseAttributes,
 };
 
 pub struct Stop;
 
-impl Command for Stop {
-    type Request = ();
-    type Response = ();
-    const COMMAND: &'static str = "stop";
+empty_command_request!(Stop, "stop");
 
-    fn serialize_request(&self, _request: Self::Request) -> String {
-        Self::COMMAND.to_string()
-    }
+empty_command_response!(Stop);
 
-    fn parse_request(mut parts: RequestTokenizer<'_>) -> Result<Self::Request, RequestParserError> {
-        debug_assert!(parts.next().is_none());
-        Ok(())
-    }
-
-    fn parse_response(
-        parts: ResponseAttributes<'_>,
-    ) -> Result<Self::Response, ResponseParserError<'_>> {
-        debug_assert!(parts.is_empty());
-        Ok(())
-    }
+impl Command<'_, '_> for Stop {
+    type Request = StopRequest;
+    type Response = StopResponse;
 }

src/commands/mounts_and_neighbors/listmounts.rs

@@ -1,39 +1,21 @@
 use crate::{
-    commands::{Command, RequestParserError, ResponseParserError},
+    commands::{
+        Command, RequestParserError, ResponseParserError, empty_command_request,
+        multi_item_command_response,
+    },
     request_tokenizer::RequestTokenizer,
     response_tokenizer::{ResponseAttributes, expect_property_type},
 };
 
 pub struct ListMounts;
 
-impl Command for ListMounts {
-    type Request = ();
-    type Response = Vec<String>;
-    const COMMAND: &'static str = "listmounts";
+empty_command_request!(ListMounts, "listmounts");
 
-    fn serialize_request(&self, _request: Self::Request) -> String {
-        Self::COMMAND.to_string()
-    }
+multi_item_command_response!(ListMounts, "mount", String);
 
-    fn parse_request(mut parts: RequestTokenizer<'_>) -> Result<Self::Request, RequestParserError> {
-        debug_assert!(parts.next().is_none());
-        Ok(())
-    }
-
-    fn parse_response(
-        parts: ResponseAttributes<'_>,
-    ) -> Result<Self::Response, ResponseParserError<'_>> {
-        let parts: Vec<_> = parts.into_vec()?;
-        let mut result = Vec::with_capacity(parts.len());
-        for (key, value) in parts.into_iter() {
-            if key != "mount" {
-                return Err(ResponseParserError::UnexpectedProperty(key));
-            }
-            let value = expect_property_type!(Some(value), "mount", Text).to_string();
-            result.push(value);
-        }
-        Ok(result)
-    }
+impl Command<'_, '_> for ListMounts {
+    type Request = ListMountsRequest;
+    type Response = ListMountsResponse;
 }
 
 #[cfg(test)]
@@ -49,7 +31,13 @@ mod tests {
             mount: /mnt/music
             OK
         "};
-        let result = ListMounts::parse_raw_response(input);
-        assert_eq!(result, Ok(vec!["".to_string(), "/mnt/music".to_string(),]));
+        let result = ListMounts::parse_raw_response(input.as_bytes());
+        assert_eq!(
+            result,
+            Ok(ListMountsResponse(vec![
+                "".to_string(),
+                "/mnt/music".to_string(),
+            ]))
+        );
     }
 }

src/commands/mounts_and_neighbors/listneighbors.rs

@@ -1,32 +1,29 @@
 use std::collections::HashMap;
 
 use crate::{
-    commands::{Command, RequestParserError, ResponseParserError},
+    commands::{
+        Command, CommandResponse, RequestParserError, ResponseParserError, empty_command_request,
+    },
     request_tokenizer::RequestTokenizer,
     response_tokenizer::{ResponseAttributes, expect_property_type},
 };
 
 pub struct ListNeighbors;
 
-pub type ListNeighborsResponse = HashMap<String, String>;
+empty_command_request!(ListNeighbors, "listneighbors");
 
-impl Command for ListNeighbors {
-    type Request = ();
-    type Response = ListNeighborsResponse;
-    const COMMAND: &'static str = "listneighbors";
+pub struct ListNeighborsResponse(HashMap<String, String>);
 
-    fn serialize_request(&self, _request: Self::Request) -> String {
-        Self::COMMAND.to_string()
+impl CommandResponse<'_> for ListNeighborsResponse {
+    fn into_response_enum(self) -> crate::Response {
+        todo!()
     }
 
-    fn parse_request(mut parts: RequestTokenizer<'_>) -> Result<Self::Request, RequestParserError> {
-        debug_assert!(parts.next().is_none());
-        Ok(())
+    fn from_response_enum(response: crate::Response) -> Option<Self> {
+        todo!()
     }
 
-    fn parse_response(
-        parts: ResponseAttributes<'_>,
-    ) -> Result<Self::Response, ResponseParserError<'_>> {
+    fn parse(parts: ResponseAttributes<'_>) -> Result<Self, ResponseParserError<'_>> {
         let parts: Vec<_> = parts.into_vec()?;
         debug_assert!(parts.len() % 2 == 0);
 
@@ -45,6 +42,11 @@ impl Command for ListNeighbors {
             result.insert(neighbor, name);
         }
 
-        Ok(result)
+        Ok(ListNeighborsResponse(result))
     }
 }
+
+impl Command<'_, '_> for ListNeighbors {
+    type Request = ListNeighborsRequest;
+    type Response = ListNeighborsResponse;
+}

src/commands/mounts_and_neighbors/mount.rs

@@ -1,7 +1,11 @@
 use serde::{Deserialize, Serialize};
 
 use crate::{
-    commands::{Command, RequestParserError, ResponseParserError},
+    commands::{
+        Command, CommandRequest, RequestParserError, ResponseParserError, empty_command_request,
+        empty_command_response,
+    },
+    common::types::{MountPath, Uri},
     request_tokenizer::RequestTokenizer,
     response_tokenizer::ResponseAttributes,
 };
@@ -10,20 +14,35 @@ pub struct Mount;
 
 #[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
 pub struct MountRequest {
-    pub path: String,
-    pub uri: String,
+    pub path: MountPath,
+    pub uri: Uri,
 }
 
-impl Command for Mount {
-    type Request = MountRequest;
-    type Response = ();
+impl CommandRequest<'_> for MountRequest {
     const COMMAND: &'static str = "mount";
 
-    fn serialize_request(&self, request: Self::Request) -> String {
-        format!("{} {} {}", Self::COMMAND, request.path, request.uri)
+    fn into_request_enum(self) -> crate::Request {
+        crate::Request::Mount(self.path, self.uri)
     }
 
-    fn parse_request(mut parts: RequestTokenizer<'_>) -> Result<Self::Request, RequestParserError> {
+    fn from_request_enum(request: crate::Request) -> Option<Self> {
+        match request {
+            crate::Request::Mount(path, uri) => Some(MountRequest { path, uri }),
+            _ => None,
+        }
+    }
+
+    fn serialize(&self) -> String {
+        debug_assert!(!self.path.to_str().is_none());
+        format!(
+            "{} {} {}",
+            Self::COMMAND,
+            self.path.to_str().unwrap_or("<invalid path>"),
+            self.uri
+        )
+    }
+
+    fn parse(mut parts: RequestTokenizer<'_>) -> Result<Self, RequestParserError> {
         let path = parts.next().ok_or(RequestParserError::UnexpectedEOF)?;
         let path = path
             .parse()
@@ -38,11 +57,11 @@ impl Command for Mount {
 
         Ok(MountRequest { path, uri })
     }
-
-    fn parse_response(
-        parts: ResponseAttributes<'_>,
-    ) -> Result<Self::Response, ResponseParserError<'_>> {
-        debug_assert!(parts.is_empty());
-        Ok(())
-    }
+}
+
+empty_command_response!(Mount);
+
+impl Command<'_, '_> for Mount {
+    type Request = MountRequest;
+    type Response = MountResponse;
 }

src/commands/mounts_and_neighbors/unmount.rs

@@ -1,37 +1,60 @@
+use std::path::PathBuf;
+
 use crate::{
-    commands::{Command, RequestParserError, ResponseParserError},
-    request_tokenizer::RequestTokenizer,
+    MountPath,
+    commands::{
+        Command, CommandRequest, RequestParserError, RequestTokenizer, ResponseParserError,
+        empty_command_response, single_item_command_request,
+    },
     response_tokenizer::ResponseAttributes,
 };
 
 pub struct Unmount;
 
-pub type UnmountRequest = String;
+#[derive(Debug, Clone, PartialEq, serde::Serialize, serde::Deserialize)]
+pub struct UnmountRequest(MountPath);
 
-impl Command for Unmount {
-    type Request = UnmountRequest;
-    type Response = ();
+impl CommandRequest<'_> for UnmountRequest {
     const COMMAND: &'static str = "unmount";
 
-    fn serialize_request(&self, request: Self::Request) -> String {
-        format!("{} {}", Self::COMMAND, request)
+    fn into_request_enum(self) -> crate::Request {
+        match Self::COMMAND {
+            "unmount" => crate::Request::Unmount(self.0),
+            _ => unimplemented!(),
+        }
     }
 
-    fn parse_request(mut parts: RequestTokenizer<'_>) -> Result<Self::Request, RequestParserError> {
-        let path = parts.next().ok_or(RequestParserError::UnexpectedEOF)?;
-        let path = path
-            .parse()
-            .map_err(|_| RequestParserError::SyntaxError(0, path.to_string()))?;
+    fn from_request_enum(request: crate::Request) -> Option<Self> {
+        match (Self::COMMAND, request) {
+            ("unmount", crate::Request::Unmount(item)) => Some(UnmountRequest(item)),
+            _ => None,
+        }
+    }
+
+    fn serialize(&self) -> String {
+        debug_assert!(!self.0.to_str().is_none());
+        format!(
+            "{} {}",
+            Self::COMMAND,
+            self.0.to_str().unwrap_or("<invalid path>")
+        )
+    }
+
+    fn parse(mut parts: RequestTokenizer<'_>) -> Result<Self, RequestParserError> {
+        let item_token = parts.next().ok_or(RequestParserError::UnexpectedEOF)?;
+        let item = item_token
+            .parse::<MountPath>()
+            .map_err(|_| RequestParserError::SyntaxError(0, item_token.to_owned()))?;
 
         debug_assert!(parts.next().is_none());
 
-        Ok(path)
-    }
-
-    fn parse_response(
-        parts: ResponseAttributes<'_>,
-    ) -> Result<Self::Response, ResponseParserError<'_>> {
-        debug_assert!(parts.is_empty());
-        Ok(())
+        Ok(UnmountRequest(item))
     }
 }
+
+empty_command_response!(Unmount);
+
+impl Command<'_, '_> for Unmount {
+    type Request = UnmountRequest;
+    type Response = UnmountResponse;
+}

src/commands/music_database/albumart.rs

@@ -3,7 +3,7 @@ use std::collections::HashMap;
 use serde::{Deserialize, Serialize};
 
 use crate::{
-    commands::{Command, RequestParserError, ResponseParserError},
+    commands::{Command, CommandRequest, CommandResponse, RequestParserError, ResponseParserError},
     common::types::{Offset, Uri},
     request_tokenizer::RequestTokenizer,
     response_tokenizer::{ResponseAttributes, get_and_parse_property, get_property},
@@ -17,22 +17,25 @@ pub struct AlbumArtRequest {
     offset: Offset,
 }
 
-#[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
-pub struct AlbumArtResponse {
-    pub size: usize,
-    pub binary: Vec<u8>,
-}
-
-impl Command for AlbumArt {
-    type Request = AlbumArtRequest;
-    type Response = AlbumArtResponse;
+impl CommandRequest<'_> for AlbumArtRequest {
     const COMMAND: &'static str = "albumart";
 
-    fn serialize_request(&self, request: Self::Request) -> String {
-        format!("{} {} {}", Self::COMMAND, request.uri, request.offset)
+    fn into_request_enum(self) -> crate::Request {
+        crate::Request::AlbumArt(self.uri, self.offset)
     }
 
-    fn parse_request(mut parts: RequestTokenizer<'_>) -> Result<Self::Request, RequestParserError> {
+    fn from_request_enum(request: crate::Request) -> Option<Self> {
+        match request {
+            crate::Request::AlbumArt(uri, offset) => Some(AlbumArtRequest { uri, offset }),
+            _ => None,
+        }
+    }
+
+    fn serialize(&self) -> String {
+        format!("{} {} {}", Self::COMMAND, self.uri, self.offset)
+    }
+
+    fn parse(mut parts: RequestTokenizer<'_>) -> Result<Self, RequestParserError> {
         let uri = match parts.next() {
             Some(s) => s,
             None => return Err(RequestParserError::UnexpectedEOF),
@@ -52,10 +55,24 @@ impl Command for AlbumArt {
             offset,
         })
     }
+}
 
-    fn parse_response(
-        parts: ResponseAttributes<'_>,
-    ) -> Result<Self::Response, ResponseParserError<'_>> {
+#[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
+pub struct AlbumArtResponse {
+    pub size: usize,
+    pub binary: Vec<u8>,
+}
+
+impl CommandResponse<'_> for AlbumArtResponse {
+    fn into_response_enum(self) -> crate::Response {
+        todo!()
+    }
+
+    fn from_response_enum(response: crate::Response) -> Option<Self> {
+        todo!()
+    }
+
+    fn parse(parts: ResponseAttributes<'_>) -> Result<Self, ResponseParserError<'_>> {
         let parts: HashMap<_, _> = parts.into_map()?;
 
         let size = get_and_parse_property!(parts, "size", Text);
@@ -65,3 +82,8 @@ impl Command for AlbumArt {
         Ok(AlbumArtResponse { size, binary })
     }
 }
+
+impl Command<'_, '_> for AlbumArt {
+    type Request = AlbumArtRequest;
+    type Response = AlbumArtResponse;
+}

src/commands/music_database/count.rs

@@ -3,7 +3,7 @@ use std::collections::HashMap;
 use serde::{Deserialize, Serialize};
 
 use crate::{
-    commands::{Command, RequestParserError, ResponseParserError},
+    commands::{Command, CommandRequest, CommandResponse, RequestParserError, ResponseParserError},
     common::types::GroupType,
     filter::Filter,
     request_tokenizer::RequestTokenizer,
@@ -18,26 +18,29 @@ pub struct CountRequest {
     group: Option<GroupType>,
 }
 
-#[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
-pub struct CountResponse {
-    pub songs: usize,
-    pub playtime: u64,
-}
-
-impl Command for Count {
-    type Request = CountRequest;
-    type Response = CountResponse;
+impl CommandRequest<'_> for CountRequest {
     const COMMAND: &'static str = "count";
 
-    fn serialize_request(&self, request: Self::Request) -> String {
-        let mut cmd = format!("{} {}", Self::COMMAND, request.filter);
-        if let Some(group) = request.group {
+    fn into_request_enum(self) -> crate::Request {
+        crate::Request::Count(self.filter, self.group)
+    }
+
+    fn from_request_enum(request: crate::Request) -> Option<Self> {
+        match request {
+            crate::Request::Count(filter, group) => Some(CountRequest { filter, group }),
+            _ => None,
+        }
+    }
+
+    fn serialize(&self) -> String {
+        let mut cmd = format!("{} {}", Self::COMMAND, self.filter);
+        if let Some(group) = self.group.as_ref() {
             cmd.push_str(&format!(" group {}", group));
         }
         cmd
     }
 
-    fn parse_request(mut parts: RequestTokenizer<'_>) -> Result<Self::Request, RequestParserError> {
+    fn parse(mut parts: RequestTokenizer<'_>) -> Result<Self, RequestParserError> {
         let filter = match parts.next() {
             Some(f) => {
                 Filter::parse(f).map_err(|_| RequestParserError::SyntaxError(1, f.to_owned()))?
@@ -61,10 +64,24 @@ impl Command for Count {
 
         Ok(CountRequest { filter, group })
     }
+}
 
-    fn parse_response(
-        parts: ResponseAttributes<'_>,
-    ) -> Result<Self::Response, ResponseParserError<'_>> {
+#[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
+pub struct CountResponse {
+    pub songs: usize,
+    pub playtime: u64,
+}
+
+impl CommandResponse<'_> for CountResponse {
+    fn into_response_enum(self) -> crate::Response {
+        todo!()
+    }
+
+    fn from_response_enum(response: crate::Response) -> Option<Self> {
+        todo!()
+    }
+
+    fn parse(parts: ResponseAttributes<'_>) -> Result<Self, ResponseParserError<'_>> {
         let parts: HashMap<_, _> = parts.into_map()?;
 
         let songs = get_and_parse_property!(parts, "songs", Text);
@@ -73,3 +90,8 @@ impl Command for Count {
         Ok(CountResponse { songs, playtime })
     }
 }
+
+impl Command<'_, '_> for Count {
+    type Request = CountRequest;
+    type Response = CountResponse;
+}

src/commands/music_database/find.rs

@@ -1,7 +1,7 @@
 use serde::{Deserialize, Serialize};
 
 use crate::{
-    commands::{Command, RequestParserError, ResponseParserError},
+    commands::{Command, CommandRequest, CommandResponse, RequestParserError, ResponseParserError},
     common::types::{Sort, WindowRange},
     filter::Filter,
     request_tokenizer::RequestTokenizer,
@@ -17,26 +17,36 @@ pub struct FindRequest {
     window: Option<WindowRange>,
 }
 
-#[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
-pub struct FindResponse {}
-
-impl Command for Find {
-    type Request = FindRequest;
-    type Response = FindResponse;
+impl CommandRequest<'_> for FindRequest {
     const COMMAND: &'static str = "find";
 
-    fn serialize_request(&self, request: Self::Request) -> String {
-        let mut cmd = format!("{} {}", Self::COMMAND, request.filter);
-        if let Some(sort) = request.sort {
+    fn into_request_enum(self) -> crate::Request {
+        crate::Request::Find(self.filter, self.sort, self.window)
+    }
+
+    fn from_request_enum(request: crate::Request) -> Option<Self> {
+        match request {
+            crate::Request::Find(filter, sort, window) => Some(FindRequest {
+                filter,
+                sort,
+                window,
+            }),
+            _ => None,
+        }
+    }
+
+    fn serialize(&self) -> String {
+        let mut cmd = format!("{} {}", Self::COMMAND, self.filter);
+        if let Some(sort) = &self.sort {
             cmd.push_str(&format!(" sort {}", sort));
         }
-        if let Some(window) = request.window {
+        if let Some(window) = &self.window {
             cmd.push_str(&format!(" window {}", window));
         }
         cmd
     }
 
-    fn parse_request(mut parts: RequestTokenizer<'_>) -> Result<Self::Request, RequestParserError> {
+    fn parse(mut parts: RequestTokenizer<'_>) -> Result<Self, RequestParserError> {
         let filter = match parts.next() {
             Some(f) => {
                 Filter::parse(f).map_err(|_| RequestParserError::SyntaxError(1, f.to_owned()))?
@@ -72,10 +82,26 @@ impl Command for Find {
             window,
         })
     }
+}
 
-    fn parse_response(
-        parts: ResponseAttributes<'_>,
-    ) -> Result<Self::Response, ResponseParserError<'_>> {
+#[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
+pub struct FindResponse {}
+
+impl CommandResponse<'_> for FindResponse {
+    fn into_response_enum(self) -> crate::Response {
+        todo!()
+    }
+
+    fn from_response_enum(response: crate::Response) -> Option<Self> {
+        todo!()
+    }
+
+    fn parse(parts: ResponseAttributes<'_>) -> Result<Self, ResponseParserError<'_>> {
         unimplemented!()
     }
 }
+
+impl Command<'_, '_> for Find {
+    type Request = FindRequest;
+    type Response = FindResponse;
+}

src/commands/music_database/findadd.rs

@@ -1,7 +1,9 @@
 use serde::{Deserialize, Serialize};
 
 use crate::{
-    commands::{Command, RequestParserError, ResponseParserError},
+    commands::{
+        Command, CommandRequest, RequestParserError, ResponseParserError, empty_command_response,
+    },
     common::types::{SongPosition, Sort, WindowRange},
     filter::Filter,
     request_tokenizer::RequestTokenizer,
@@ -18,26 +20,40 @@ pub struct FindAddRequest {
     position: Option<SongPosition>,
 }
 
-impl Command for FindAdd {
-    type Request = FindAddRequest;
-    type Response = ();
+impl CommandRequest<'_> for FindAddRequest {
     const COMMAND: &'static str = "findadd";
 
-    fn serialize_request(&self, request: Self::Request) -> String {
-        let mut cmd = format!("{} {}", Self::COMMAND, request.filter);
-        if let Some(sort) = request.sort {
+    fn into_request_enum(self) -> crate::Request {
+        crate::Request::FindAdd(self.filter, self.sort, self.window, self.position)
+    }
+
+    fn from_request_enum(request: crate::Request) -> Option<Self> {
+        match request {
+            crate::Request::FindAdd(filter, sort, window, position) => Some(FindAddRequest {
+                filter,
+                sort,
+                window,
+                position,
+            }),
+            _ => None,
+        }
+    }
+
+    fn serialize(&self) -> String {
+        let mut cmd = format!("{} {}", Self::COMMAND, self.filter);
+        if let Some(sort) = &self.sort {
             cmd.push_str(&format!(" sort {}", sort));
         }
-        if let Some(window) = request.window {
+        if let Some(window) = &self.window {
             cmd.push_str(&format!(" window {}", window));
         }
-        if let Some(position) = request.position {
+        if let Some(position) = &self.position {
             cmd.push_str(&format!(" position {}", position));
         }
         cmd
     }
 
-    fn parse_request(mut parts: RequestTokenizer<'_>) -> Result<Self::Request, RequestParserError> {
+    fn parse(mut parts: RequestTokenizer<'_>) -> Result<Self, RequestParserError> {
         let filter = match parts.next() {
             Some(f) => {
                 Filter::parse(f).map_err(|_| RequestParserError::SyntaxError(1, f.to_owned()))?
@@ -84,11 +100,11 @@ impl Command for FindAdd {
             position,
         })
     }
-
-    fn parse_response(
-        parts: ResponseAttributes<'_>,
-    ) -> Result<Self::Response, ResponseParserError<'_>> {
-        debug_assert!(parts.is_empty());
-        Ok(())
-    }
+}
+
+empty_command_response!(FindAdd);
+
+impl Command<'_, '_> for FindAdd {
+    type Request = FindAddRequest;
+    type Response = FindAddResponse;
 }

src/commands/music_database/getfingerprint.rs

@@ -3,7 +3,10 @@ use std::collections::HashMap;
 use serde::{Deserialize, Serialize};
 
 use crate::{
-    commands::{Command, RequestParserError, ResponseParserError},
+    commands::{
+        Command, CommandResponse, RequestParserError, ResponseParserError,
+        single_item_command_request,
+    },
     common::types::Uri,
     request_tokenizer::RequestTokenizer,
     response_tokenizer::{ResponseAttributes, get_and_parse_property},
@@ -11,34 +14,23 @@ use crate::{
 
 pub struct GetFingerprint;
 
+single_item_command_request!(GetFingerprint, "getfingerprint", Uri);
+
 #[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
 pub struct GetFingerprintResponse {
     pub chromaprint: String,
 }
 
-impl Command for GetFingerprint {
-    type Request = Uri;
-    type Response = GetFingerprintResponse;
-    const COMMAND: &'static str = "getfingerprint";
-
-    fn serialize_request(&self, request: Self::Request) -> String {
-        format!("{} {}", Self::COMMAND, request)
+impl CommandResponse<'_> for GetFingerprintResponse {
+    fn into_response_enum(self) -> crate::Response {
+        todo!()
     }
 
-    fn parse_request(mut parts: RequestTokenizer<'_>) -> Result<Self::Request, RequestParserError> {
-        let uri = parts.next().ok_or(RequestParserError::UnexpectedEOF)?;
-        let uri = uri
-            .parse()
-            .map_err(|_| RequestParserError::SyntaxError(1, uri.to_owned()))?;
-
-        debug_assert!(parts.next().is_none());
-
-        Ok(uri)
+    fn from_response_enum(response: crate::Response) -> Option<Self> {
+        todo!()
     }
 
-    fn parse_response(
-        parts: ResponseAttributes<'_>,
-    ) -> Result<Self::Response, ResponseParserError<'_>> {
+    fn parse(parts: ResponseAttributes<'_>) -> Result<Self, ResponseParserError<'_>> {
         let parts: HashMap<_, _> = parts.into_map()?;
 
         let chromaprint = get_and_parse_property!(parts, "chromaprint", Text);
@@ -46,3 +38,8 @@ impl Command for GetFingerprint {
         Ok(GetFingerprintResponse { chromaprint })
     }
 }
+
+impl Command<'_, '_> for GetFingerprint {
+    type Request = GetFingerprintRequest;
+    type Response = GetFingerprintResponse;
+}

src/commands/music_database/list.rs

@@ -1,7 +1,10 @@
 use serde::{Deserialize, Serialize};
 
 use crate::{
-    commands::{Command, RequestParserError, ResponseParserError},
+    commands::{
+        Command, CommandRequest, CommandResponse, RequestParserError, ResponseParserError,
+        multi_item_command_response,
+    },
     common::types::{GroupType, TagName, WindowRange},
     filter::Filter,
     request_tokenizer::RequestTokenizer,
@@ -18,28 +21,40 @@ pub struct ListRequest {
     window: Option<WindowRange>,
 }
 
-pub type ListResponse = Vec<String>;
-
-impl Command for List {
-    type Request = ListRequest;
-    type Response = ListResponse;
+impl CommandRequest<'_> for ListRequest {
     const COMMAND: &'static str = "list";
 
-    fn serialize_request(&self, request: Self::Request) -> String {
-        let mut cmd = match &request.filter {
-            Some(f) => format!("{} {} {}", Self::COMMAND, request.tagname, f),
-            None => format!("{} {}", Self::COMMAND, request.tagname),
+    fn into_request_enum(self) -> crate::Request {
+        crate::Request::List(self.tagname, self.filter, self.groups, self.window)
+    }
+
+    fn from_request_enum(request: crate::Request) -> Option<Self> {
+        match request {
+            crate::Request::List(tagname, filter, groups, window) => Some(ListRequest {
+                tagname,
+                filter,
+                groups,
+                window,
+            }),
+            _ => None,
+        }
+    }
+
+    fn serialize(&self) -> String {
+        let mut cmd = match &self.filter {
+            Some(f) => format!("{} {} {}", Self::COMMAND, self.tagname, f),
+            None => format!("{} {}", Self::COMMAND, self.tagname),
         };
-        for group in request.groups {
+        for group in &self.groups {
             cmd.push_str(&format!(" group {}", group));
         }
-        if let Some(window) = request.window {
+        if let Some(window) = &self.window {
             cmd.push_str(&format!(" window {}", window));
         }
         cmd
     }
 
-    fn parse_request(mut parts: RequestTokenizer<'_>) -> Result<Self::Request, RequestParserError> {
+    fn parse(mut parts: RequestTokenizer<'_>) -> Result<Self, RequestParserError> {
         let tagname = parts.next().ok_or(RequestParserError::UnexpectedEOF)?;
         let tagname = tagname
             .parse()
@@ -91,10 +106,20 @@ impl Command for List {
             window,
         })
     }
+}
 
-    fn parse_response(
-        parts: ResponseAttributes<'_>,
-    ) -> Result<Self::Response, ResponseParserError<'_>> {
+pub struct ListResponse(Vec<String>);
+
+impl CommandResponse<'_> for ListResponse {
+    fn into_response_enum(self) -> crate::Response {
+        todo!()
+    }
+
+    fn from_response_enum(response: crate::Response) -> Option<Self> {
+        todo!()
+    }
+
+    fn parse(parts: ResponseAttributes<'_>) -> Result<Self, ResponseParserError<'_>> {
         let parts_: Vec<_> = parts.into_vec()?;
         debug_assert!({
             let key = parts_.first().map(|(k, _)| k);
@@ -106,6 +131,11 @@ impl Command for List {
             .map(|(k, v)| Ok(expect_property_type!(Some(v), k, Text).to_string()))
             .collect::<Result<Vec<_>, ResponseParserError>>()?;
 
-        Ok(list)
+        Ok(ListResponse(list))
     }
 }
+
+impl Command<'_, '_> for List {
+    type Request = ListRequest;
+    type Response = ListResponse;
+}

src/commands/music_database/listall.rs

@@ -10,7 +10,7 @@ pub struct ListAll;
 // TODO: This is supposed to be a tree-like structure, with directories containing files and playlists
 pub type ListAllResponse = Vec<String>;
 
-impl Command for ListAll {
+impl Command<'_, '_> for ListAll {
     type Request = Option<Uri>;
     type Response = ListAllResponse;
     const COMMAND: &'static str = "listall";

src/commands/music_database/listallinfo.rs

@@ -11,7 +11,7 @@ pub struct ListAllInfo;
 //       in addition to the metadata of each entry
 pub type ListAllInfoResponse = Vec<String>;
 
-impl Command for ListAllInfo {
+impl Command<'_, '_> for ListAllInfo {
     type Request = Option<Uri>;
     type Response = ListAllInfoResponse;
     const COMMAND: &'static str = "listallinfo";

src/commands/music_database/listfiles.rs

@@ -10,7 +10,7 @@ pub struct ListFiles;
 // TODO: fix this type
 pub type ListFilesResponse = Vec<String>;
 
-impl Command for ListFiles {
+impl Command<'_, '_> for ListFiles {
     type Request = Option<Uri>;
     type Response = ListFilesResponse;
     const COMMAND: &'static str = "listfiles";

src/commands/music_database/lsinfo.rs

@@ -17,7 +17,7 @@ pub struct LsInfoResponseEntry {
     last_modified: Option<String>,
 }
 
-impl Command for LsInfo {
+impl Command<'_, '_> for LsInfo {
     type Request = Option<Uri>;
     type Response = LsInfoResponse;
     const COMMAND: &'static str = "lsinfo";

src/commands/music_database/readcomments.rs

@@ -11,7 +11,7 @@ pub struct ReadComments;
 
 pub type ReadCommentsResponse = HashMap<String, String>;
 
-impl Command for ReadComments {
+impl Command<'_, '_> for ReadComments {
     type Request = Uri;
     type Response = ReadCommentsResponse;
     const COMMAND: &'static str = "readcomments";

src/commands/music_database/readpicture.rs

@@ -26,7 +26,7 @@ pub struct ReadPictureResponse {
     pub mimetype: Option<String>,
 }
 
-impl Command for ReadPicture {
+impl Command<'_, '_> for ReadPicture {
     type Request = ReadPictureRequest;
     type Response = Option<ReadPictureResponse>;
     const COMMAND: &'static str = "readpicture";

src/commands/music_database/rescan.rs

@@ -16,7 +16,7 @@ pub struct RescanResponse {
     pub updating_db: usize,
 }
 
-impl Command for Rescan {
+impl Command<'_, '_> for Rescan {
     type Request = Option<Uri>;
     type Response = RescanResponse;
     const COMMAND: &'static str = "rescan";

src/commands/music_database/search.rs

@@ -20,7 +20,7 @@ pub struct SearchRequest {
 #[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
 pub struct SearchResponse {}
 
-impl Command for Search {
+impl Command<'_, '_> for Search {
     type Request = SearchRequest;
     type Response = SearchResponse;
     const COMMAND: &'static str = "search";

src/commands/music_database/searchadd.rs

@@ -17,7 +17,7 @@ pub struct SearchAddRequest {
     position: Option<SongPosition>,
 }
 
-impl Command for SearchAdd {
+impl Command<'_, '_> for SearchAdd {
     type Request = SearchAddRequest;
     type Response = ();
     const COMMAND: &'static str = "searchadd";

src/commands/music_database/searchaddpl.rs

@@ -18,7 +18,7 @@ pub struct SearchAddPlRequest {
     position: Option<SongPosition>,
 }
 
-impl Command for SearchAddPl {
+impl Command<'_, '_> for SearchAddPl {
     type Request = SearchAddPlRequest;
     type Response = ();
     const COMMAND: &'static str = "searchaddpl";

src/commands/music_database/searchcount.rs

@@ -24,7 +24,7 @@ pub struct SearchCountResponse {
     pub playtime: u64,
 }
 
-impl Command for SearchCount {
+impl Command<'_, '_> for SearchCount {
     type Request = SearchCountRequest;
     type Response = SearchCountResponse;
     const COMMAND: &'static str = "searchcount";

src/commands/music_database/update.rs

@@ -16,7 +16,7 @@ pub struct UpdateResponse {
     updating_db: usize,
 }
 
-impl Command for Update {
+impl Command<'_, '_> for Update {
     type Request = Option<Uri>;
     type Response = UpdateResponse;
     const COMMAND: &'static str = "update";

src/commands/partition_commands/delpartition.rs

@@ -1,5 +1,8 @@
 use crate::{
-    commands::{Command, RequestParserError, ResponseParserError},
+    commands::{
+        Command, RequestParserError, ResponseParserError, empty_command_response,
+        single_item_command_request,
+    },
     common::types::PartitionName,
     request_tokenizer::RequestTokenizer,
     response_tokenizer::ResponseAttributes,
@@ -7,30 +10,11 @@ use crate::{
 
 pub struct DelPartition;
 
-impl Command for DelPartition {
-    type Request = PartitionName;
-    type Response = ();
-    const COMMAND: &'static str = "delpartition";
+single_item_command_request!(DelPartition, "delpartition", PartitionName);
 
-    fn serialize_request(&self, request: Self::Request) -> String {
-        format!("{} {}", Self::COMMAND, request)
-    }
+empty_command_response!(DelPartition);
 
-    fn parse_request(mut parts: RequestTokenizer<'_>) -> Result<Self::Request, RequestParserError> {
-        let partition = parts
-            .next()
-            .ok_or(RequestParserError::UnexpectedEOF)?
-            .to_string();
-
-        debug_assert!(parts.next().is_none());
-
-        Ok(partition)
-    }
-
-    fn parse_response(
-        parts: ResponseAttributes<'_>,
-    ) -> Result<Self::Response, ResponseParserError<'_>> {
-        debug_assert!(parts.is_empty());
-        Ok(())
-    }
+impl Command<'_, '_> for DelPartition {
+    type Request = DelPartitionRequest;
+    type Response = DelPartitionResponse;
 }

src/commands/partition_commands/listpartitions.rs

@@ -1,5 +1,8 @@
 use crate::{
-    commands::{Command, RequestParserError, ResponseParserError},
+    commands::{
+        Command, RequestParserError, ResponseParserError, empty_command_request,
+        multi_item_command_response, single_item_command_request,
+    },
     common::types::PartitionName,
     request_tokenizer::RequestTokenizer,
     response_tokenizer::{ResponseAttributes, expect_property_type},
@@ -7,36 +10,11 @@ use crate::{
 
 pub struct ListPartitions;
 
-pub type ListPartitionsResponse = Vec<PartitionName>;
+empty_command_request!(ListPartitions, "listpartitions");
 
-impl Command for ListPartitions {
-    type Request = ();
+multi_item_command_response!(ListPartitions, "partition", PartitionName);
+
+impl Command<'_, '_> for ListPartitions {
+    type Request = ListPartitionsRequest;
     type Response = ListPartitionsResponse;
-    const COMMAND: &'static str = "listpartitions";
-
-    fn serialize_request(&self, _request: Self::Request) -> String {
-        Self::COMMAND.to_string()
-    }
-
-    fn parse_request(mut parts: RequestTokenizer<'_>) -> Result<Self::Request, RequestParserError> {
-        debug_assert!(parts.next().is_none());
-        Ok(())
-    }
-
-    fn parse_response(
-        parts: ResponseAttributes<'_>,
-    ) -> Result<Self::Response, ResponseParserError<'_>> {
-        let parts: Vec<_> = parts.into_vec()?;
-
-        let mut partitions = Vec::with_capacity(parts.len());
-        for (key, value) in parts.into_iter() {
-            if key != "partition" {
-                return Err(ResponseParserError::UnexpectedProperty(key));
-            }
-            let partition = expect_property_type!(Some(value), "partition", Text).to_string();
-            partitions.push(partition);
-        }
-
-        Ok(partitions)
-    }
 }

src/commands/partition_commands/moveoutput.rs

@@ -1,35 +1,19 @@
 use crate::{
-    commands::{Command, RequestParserError, ResponseParserError},
+    commands::{
+        Command, RequestParserError, ResponseParserError, empty_command_response,
+        single_item_command_request,
+    },
     request_tokenizer::RequestTokenizer,
     response_tokenizer::ResponseAttributes,
 };
 
 pub struct MoveOutput;
 
-impl Command for MoveOutput {
-    type Request = String;
-    type Response = ();
-    const COMMAND: &'static str = "moveoutput";
+single_item_command_request!(MoveOutput, "moveoutput", String);
 
-    fn serialize_request(&self, request: Self::Request) -> String {
-        format!("{} {}", Self::COMMAND, request)
-    }
+empty_command_response!(MoveOutput);
 
-    fn parse_request(mut parts: RequestTokenizer<'_>) -> Result<Self::Request, RequestParserError> {
-        let output_name = parts
-            .next()
-            .ok_or(RequestParserError::UnexpectedEOF)?
-            .to_string();
-
-        debug_assert!(parts.next().is_none());
-
-        Ok(output_name)
-    }
-
-    fn parse_response(
-        parts: ResponseAttributes<'_>,
-    ) -> Result<Self::Response, ResponseParserError<'_>> {
-        debug_assert!(parts.is_empty());
-        Ok(())
-    }
+impl Command<'_, '_> for MoveOutput {
+    type Request = MoveOutputRequest;
+    type Response = MoveOutputResponse;
 }

src/commands/partition_commands/newpartition.rs

@@ -1,5 +1,8 @@
 use crate::{
-    commands::{Command, RequestParserError, ResponseParserError},
+    commands::{
+        Command, RequestParserError, ResponseParserError, empty_command_request,
+        empty_command_response, single_item_command_request,
+    },
     common::types::PartitionName,
     request_tokenizer::RequestTokenizer,
     response_tokenizer::ResponseAttributes,
@@ -7,30 +10,11 @@ use crate::{
 
 pub struct NewPartition;
 
-impl Command for NewPartition {
-    type Request = PartitionName;
-    type Response = ();
-    const COMMAND: &'static str = "newpartition";
+single_item_command_request!(NewPartition, "newpartition", PartitionName);
 
-    fn serialize_request(&self, request: Self::Request) -> String {
-        format!("{} {}", Self::COMMAND, request)
-    }
+empty_command_response!(NewPartition);
 
-    fn parse_request(mut parts: RequestTokenizer<'_>) -> Result<Self::Request, RequestParserError> {
-        let partition = parts
-            .next()
-            .ok_or(RequestParserError::UnexpectedEOF)?
-            .to_string();
-
-        debug_assert!(parts.next().is_none());
-
-        Ok(partition)
-    }
-
-    fn parse_response(
-        parts: ResponseAttributes<'_>,
-    ) -> Result<Self::Response, ResponseParserError<'_>> {
-        debug_assert!(parts.is_empty());
-        Ok(())
-    }
+impl Command<'_, '_> for NewPartition {
+    type Request = NewPartitionRequest;
+    type Response = NewPartitionResponse;
 }

src/commands/partition_commands/partition.rs

@@ -1,5 +1,8 @@
 use crate::{
-    commands::{Command, RequestParserError, ResponseParserError},
+    commands::{
+        Command, RequestParserError, ResponseParserError, empty_command_response,
+        single_item_command_request,
+    },
     common::types::PartitionName,
     request_tokenizer::RequestTokenizer,
     response_tokenizer::ResponseAttributes,
@@ -7,30 +10,11 @@ use crate::{
 
 pub struct Partition;
 
-impl Command for Partition {
-    type Request = PartitionName;
-    type Response = ();
-    const COMMAND: &'static str = "partition";
+single_item_command_request!(Partition, "partition", PartitionName);
 
-    fn serialize_request(&self, request: Self::Request) -> String {
-        format!("{} {}", Self::COMMAND, request)
-    }
+empty_command_response!(Partition);
 
-    fn parse_request(mut parts: RequestTokenizer<'_>) -> Result<Self::Request, RequestParserError> {
-        let partition = parts
-            .next()
-            .ok_or(RequestParserError::UnexpectedEOF)?
-            .to_string();
-
-        debug_assert!(parts.next().is_none());
-
-        Ok(partition)
-    }
-
-    fn parse_response(
-        parts: ResponseAttributes<'_>,
-    ) -> Result<Self::Response, ResponseParserError<'_>> {
-        debug_assert!(parts.is_empty());
-        Ok(())
-    }
+impl Command<'_, '_> for Partition {
+    type Request = PartitionRequest;
+    type Response = PartitionResponse;
 }

src/commands/playback_options/consume.rs

@@ -1,7 +1,10 @@
 use std::str::FromStr;
 
 use crate::{
-    commands::{Command, RequestParserError, ResponseParserError},
+    commands::{
+        Command, RequestParserError, ResponseParserError, empty_command_response,
+        single_item_command_request,
+    },
     common::types::BoolOrOneshot,
     request_tokenizer::RequestTokenizer,
     response_tokenizer::ResponseAttributes,
@@ -9,31 +12,11 @@ use crate::{
 
 pub struct Consume;
 
-impl Command for Consume {
-    type Request = BoolOrOneshot;
-    type Response = ();
-    const COMMAND: &'static str = "consume";
+single_item_command_request!(Consume, "consume", BoolOrOneshot);
 
-    fn serialize_request(&self, request: Self::Request) -> String {
-        format!("{} {}", Self::COMMAND, request)
-    }
+empty_command_response!(Consume);
 
-    fn parse_request(mut parts: RequestTokenizer<'_>) -> Result<Self::Request, RequestParserError> {
-        let state = match parts.next() {
-            Some(s) => crate::common::types::BoolOrOneshot::from_str(s)
-                .map_err(|_| RequestParserError::SyntaxError(0, s.to_owned()))?,
-            None => return Err(RequestParserError::UnexpectedEOF),
-        };
-
-        debug_assert!(parts.next().is_none());
-
-        Ok(state)
-    }
-
-    fn parse_response(
-        parts: ResponseAttributes<'_>,
-    ) -> Result<Self::Response, ResponseParserError<'_>> {
-        debug_assert!(parts.is_empty());
-        Ok(())
-    }
+impl Command<'_, '_> for Consume {
+    type Request = ConsumeRequest;
+    type Response = ConsumeResponse;
 }

src/commands/playback_options/crossfade.rs

@@ -1,5 +1,8 @@
 use crate::{
-    commands::{Command, RequestParserError, ResponseParserError},
+    commands::{
+        Command, RequestParserError, ResponseParserError, empty_command_response,
+        single_item_command_request,
+    },
     common::types::Seconds,
     request_tokenizer::RequestTokenizer,
     response_tokenizer::ResponseAttributes,
@@ -7,32 +10,11 @@ use crate::{
 
 pub struct Crossfade;
 
-impl Command for Crossfade {
-    type Request = Seconds;
-    type Response = ();
-    const COMMAND: &'static str = "crossfade";
+single_item_command_request!(Crossfade, "crossfade", Seconds);
 
-    fn serialize_request(&self, request: Self::Request) -> String {
-        format!("{} {}", Self::COMMAND, request)
-    }
+empty_command_response!(Crossfade);
 
-    fn parse_request(mut parts: RequestTokenizer<'_>) -> Result<Self::Request, RequestParserError> {
-        let seconds = match parts.next() {
-            Some(s) => s
-                .parse::<Seconds>()
-                .map_err(|_| RequestParserError::SyntaxError(0, s.to_owned()))?,
-            None => return Err(RequestParserError::UnexpectedEOF),
-        };
-
-        debug_assert!(parts.next().is_none());
-
-        Ok(seconds)
-    }
-
-    fn parse_response(
-        parts: ResponseAttributes<'_>,
-    ) -> Result<Self::Response, ResponseParserError<'_>> {
-        debug_assert!(parts.is_empty());
-        Ok(())
-    }
+impl Command<'_, '_> for Crossfade {
+    type Request = CrossfadeRequest;
+    type Response = CrossfadeResponse;
 }

src/commands/playback_options/getvol.rs

@@ -1,7 +1,10 @@
 use std::collections::HashMap;
 
 use crate::{
-    commands::{Command, RequestParserError, ResponseParserError},
+    commands::{
+        Command, RequestParserError, ResponseParserError, empty_command_request,
+        single_item_command_response,
+    },
     common::types::VolumeValue,
     request_tokenizer::RequestTokenizer,
     response_tokenizer::{ResponseAttributes, get_and_parse_property},
@@ -9,26 +12,11 @@ use crate::{
 
 pub struct GetVol;
 
-impl Command for GetVol {
-    type Request = ();
-    type Response = VolumeValue;
-    const COMMAND: &'static str = "getvol";
+empty_command_request!(GetVol, "getvol");
 
-    fn serialize_request(&self, _request: Self::Request) -> String {
-        Self::COMMAND.to_string()
-    }
+single_item_command_response!(GetVol, "volume", VolumeValue);
 
-    fn parse_request(mut parts: RequestTokenizer<'_>) -> Result<Self::Request, RequestParserError> {
-        debug_assert!(parts.next().is_none());
-        Ok(())
-    }
-
-    fn parse_response(
-        parts: ResponseAttributes<'_>,
-    ) -> Result<Self::Response, ResponseParserError<'_>> {
-        let parts: HashMap<_, _> = parts.into_map()?;
-        assert_eq!(parts.len(), 1);
-        let volume = get_and_parse_property!(parts, "volume", Text);
-        Ok(volume)
-    }
+impl Command<'_, '_> for GetVol {
+    type Request = GetVolRequest;
+    type Response = GetVolResponse;
 }

src/commands/playback_options/mixrampdb.rs

@@ -1,37 +1,19 @@
 use crate::{
-    commands::{Command, RequestParserError, ResponseParserError},
+    commands::{
+        Command, RequestParserError, ResponseParserError, empty_command_response,
+        single_item_command_request,
+    },
     request_tokenizer::RequestTokenizer,
     response_tokenizer::ResponseAttributes,
 };
 
 pub struct MixRampDb;
 
-impl Command for MixRampDb {
-    type Request = f32;
-    type Response = ();
-    const COMMAND: &'static str = "mixrampdb";
+single_item_command_request!(MixRampDb, "mixrampdb", f32);
 
-    fn serialize_request(&self, request: Self::Request) -> String {
-        format!("{} {}", Self::COMMAND, request)
-    }
+empty_command_response!(MixRampDb);
 
-    fn parse_request(mut parts: RequestTokenizer<'_>) -> Result<Self::Request, RequestParserError> {
-        let db = match parts.next() {
-            Some(s) => s
-                .parse::<f32>()
-                .map_err(|_| RequestParserError::SyntaxError(0, s.to_owned()))?,
-            None => return Err(RequestParserError::UnexpectedEOF),
-        };
-
-        debug_assert!(parts.next().is_none());
-
-        Ok(db)
-    }
-
-    fn parse_response(
-        parts: ResponseAttributes<'_>,
-    ) -> Result<Self::Response, ResponseParserError<'_>> {
-        debug_assert!(parts.is_empty());
-        Ok(())
-    }
+impl Command<'_, '_> for MixRampDb {
+    type Request = MixRampDbRequest;
+    type Response = MixRampDbResponse;
 }

src/commands/playback_options/mixrampdelay.rs

@@ -1,5 +1,8 @@
 use crate::{
-    commands::{Command, RequestParserError, ResponseParserError},
+    commands::{
+        Command, RequestParserError, ResponseParserError, empty_command_response,
+        single_item_command_request,
+    },
     common::types::Seconds,
     request_tokenizer::RequestTokenizer,
     response_tokenizer::ResponseAttributes,
@@ -7,32 +10,10 @@ use crate::{
 
 pub struct MixRampDelay;
 
-impl Command for MixRampDelay {
-    type Request = Seconds;
-    type Response = ();
-    const COMMAND: &'static str = "mixrampdelay";
+single_item_command_request!(MixRampDelay, "mixrampdelay", Seconds);
+empty_command_response!(MixRampDelay);
 
-    fn serialize_request(&self, request: Self::Request) -> String {
-        format!("{} {}", Self::COMMAND, request)
-    }
-
-    fn parse_request(mut parts: RequestTokenizer<'_>) -> Result<Self::Request, RequestParserError> {
-        let seconds = match parts.next() {
-            Some(s) => s
-                .parse::<Seconds>()
-                .map_err(|_| RequestParserError::SyntaxError(0, s.to_owned()))?,
-            None => return Err(RequestParserError::UnexpectedEOF),
-        };
-
-        debug_assert!(parts.next().is_none());
-
-        Ok(seconds)
-    }
-
-    fn parse_response(
-        parts: ResponseAttributes<'_>,
-    ) -> Result<Self::Response, ResponseParserError<'_>> {
-        debug_assert!(parts.is_empty());
-        Ok(())
-    }
+impl Command<'_, '_> for MixRampDelay {
+    type Request = MixRampDelayRequest;
+    type Response = MixRampDelayResponse;
 }

src/commands/playback_options/random.rs

@@ -1,22 +1,35 @@
 use crate::{
-    commands::{Command, RequestParserError, ResponseParserError},
+    commands::{
+        Command, CommandRequest, RequestParserError, ResponseParserError, empty_command_response,
+    },
     request_tokenizer::RequestTokenizer,
     response_tokenizer::ResponseAttributes,
 };
 
 pub struct Random;
 
-impl Command for Random {
-    type Request = bool;
-    type Response = ();
+pub struct RandomRequest(bool);
+
+impl CommandRequest<'_> for RandomRequest {
     const COMMAND: &'static str = "random";
 
-    fn serialize_request(&self, request: Self::Request) -> String {
-        let state = if request { "1" } else { "0" };
+    fn into_request_enum(self) -> crate::Request {
+        crate::Request::Random(self.0)
+    }
+
+    fn from_request_enum(request: crate::Request) -> Option<Self> {
+        match request {
+            crate::Request::Random(state) => Some(RandomRequest(state)),
+            _ => None,
+        }
+    }
+
+    fn serialize(&self) -> String {
+        let state = if self.0 { "1" } else { "0" };
         format!("{} {}", Self::COMMAND, state)
     }
 
-    fn parse_request(mut parts: RequestTokenizer<'_>) -> Result<Self::Request, RequestParserError> {
+    fn parse(mut parts: RequestTokenizer<'_>) -> Result<Self, RequestParserError> {
         let state = match parts.next() {
             Some("0") => false,
             Some("1") => true,
@@ -26,13 +39,13 @@ impl Command for Random {
 
         debug_assert!(parts.next().is_none());
 
-        Ok(state)
-    }
-
-    fn parse_response(
-        parts: ResponseAttributes<'_>,
-    ) -> Result<Self::Response, ResponseParserError<'_>> {
-        debug_assert!(parts.is_empty());
-        Ok(())
+        Ok(RandomRequest(state))
     }
 }
+
+empty_command_response!(Random);
+
+impl Command<'_, '_> for Random {
+    type Request = RandomRequest;
+    type Response = RandomResponse;
+}

src/commands/playback_options/repeat.rs

@@ -1,22 +1,35 @@
 use crate::{
-    commands::{Command, RequestParserError, ResponseParserError},
+    commands::{
+        Command, CommandRequest, RequestParserError, ResponseParserError, empty_command_response,
+    },
     request_tokenizer::RequestTokenizer,
     response_tokenizer::ResponseAttributes,
 };
 
 pub struct Repeat;
 
-impl Command for Repeat {
-    type Request = bool;
-    type Response = ();
+pub struct RepeatRequest(bool);
+
+impl CommandRequest<'_> for RepeatRequest {
     const COMMAND: &'static str = "repeat";
 
-    fn serialize_request(&self, request: Self::Request) -> String {
-        let state = if request { "1" } else { "0" };
+    fn into_request_enum(self) -> crate::Request {
+        crate::Request::Repeat(self.0)
+    }
+
+    fn from_request_enum(request: crate::Request) -> Option<Self> {
+        match request {
+            crate::Request::Repeat(state) => Some(RepeatRequest(state)),
+            _ => None,
+        }
+    }
+
+    fn serialize(&self) -> String {
+        let state = if self.0 { "1" } else { "0" };
         format!("{} {}", Self::COMMAND, state)
     }
 
-    fn parse_request(mut parts: RequestTokenizer<'_>) -> Result<Self::Request, RequestParserError> {
+    fn parse(mut parts: RequestTokenizer<'_>) -> Result<Self, RequestParserError> {
         let state = match parts.next() {
             Some("0") => false,
             Some("1") => true,
@@ -26,13 +39,13 @@ impl Command for Repeat {
 
         debug_assert!(parts.next().is_none());
 
-        Ok(state)
-    }
-
-    fn parse_response(
-        parts: ResponseAttributes<'_>,
-    ) -> Result<Self::Response, ResponseParserError<'_>> {
-        debug_assert!(parts.is_empty());
-        Ok(())
+        Ok(RepeatRequest(state))
     }
 }
+
+empty_command_response!(Repeat);
+
+impl Command<'_, '_> for Repeat {
+    type Request = RepeatRequest;
+    type Response = RepeatResponse;
+}

src/commands/playback_options/replay_gain_mode.rs

@@ -1,7 +1,10 @@
 use std::str::FromStr;
 
 use crate::{
-    commands::{Command, RequestParserError, ResponseParserError},
+    commands::{
+        Command, RequestParserError, ResponseParserError, empty_command_response,
+        single_item_command_request,
+    },
     common::types::ReplayGainModeMode,
     request_tokenizer::RequestTokenizer,
     response_tokenizer::ResponseAttributes,
@@ -9,31 +12,11 @@ use crate::{
 
 pub struct ReplayGainMode;
 
-impl Command for ReplayGainMode {
-    type Request = ReplayGainModeMode;
-    type Response = ();
-    const COMMAND: &'static str = "replay_gain_mode";
+single_item_command_request!(ReplayGainMode, "replay_gain_mode", ReplayGainModeMode);
 
-    fn serialize_request(&self, request: Self::Request) -> String {
-        format!("{} {}", Self::COMMAND, request)
-    }
+empty_command_response!(ReplayGainMode);
 
-    fn parse_request(mut parts: RequestTokenizer<'_>) -> Result<Self::Request, RequestParserError> {
-        let mode = match parts.next() {
-            Some(s) => ReplayGainModeMode::from_str(s)
-                .map_err(|_| RequestParserError::SyntaxError(0, s.to_owned()))?,
-            None => return Err(RequestParserError::UnexpectedEOF),
-        };
-
-        debug_assert!(parts.next().is_none());
-
-        Ok(mode)
-    }
-
-    fn parse_response(
-        parts: ResponseAttributes<'_>,
-    ) -> Result<Self::Response, ResponseParserError<'_>> {
-        debug_assert!(parts.is_empty());
-        Ok(())
-    }
+impl Command<'_, '_> for ReplayGainMode {
+    type Request = ReplayGainModeRequest;
+    type Response = ReplayGainModeResponse;
 }

src/commands/playback_options/replay_gain_status.rs

@@ -3,7 +3,9 @@ use std::{collections::HashMap, str::FromStr};
 use serde::{Deserialize, Serialize};
 
 use crate::{
-    commands::{Command, RequestParserError, ResponseParserError},
+    commands::{
+        Command, CommandResponse, RequestParserError, ResponseParserError, empty_command_request,
+    },
     common::types::ReplayGainModeMode,
     request_tokenizer::RequestTokenizer,
     response_tokenizer::{ResponseAttributes, get_property},
@@ -11,28 +13,23 @@ use crate::{
 
 pub struct ReplayGainStatus;
 
+empty_command_request!(ReplayGainStatus, "replay_gain_status");
+
 #[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
 pub struct ReplayGainStatusResponse {
     pub replay_gain_mode: ReplayGainModeMode,
 }
 
-impl Command for ReplayGainStatus {
-    type Request = ();
-    type Response = ReplayGainStatusResponse;
-    const COMMAND: &'static str = "replay_gain_status";
-
-    fn serialize_request(&self, _: Self::Request) -> String {
-        Self::COMMAND.to_string()
+impl CommandResponse<'_> for ReplayGainStatusResponse {
+    fn into_response_enum(self) -> crate::Response {
+        todo!()
     }
 
-    fn parse_request(mut parts: RequestTokenizer<'_>) -> Result<Self::Request, RequestParserError> {
-        debug_assert!(parts.next().is_none());
-        Ok(())
+    fn from_response_enum(response: crate::Response) -> Option<Self> {
+        todo!()
     }
 
-    fn parse_response(
-        parts: ResponseAttributes<'_>,
-    ) -> Result<Self::Response, ResponseParserError<'_>> {
+    fn parse(parts: ResponseAttributes<'_>) -> Result<Self, ResponseParserError<'_>> {
         let parts: HashMap<_, _> = parts.into_map()?;
         let replay_gain_mode = get_property!(parts, "replay_gain_mode", Text);
 
@@ -43,3 +40,8 @@ impl Command for ReplayGainStatus {
         })
     }
 }
+
+impl Command<'_, '_> for ReplayGainStatus {
+    type Request = ReplayGainStatusRequest;
+    type Response = ReplayGainStatusResponse;
+}

src/commands/playback_options/setvol.rs

@@ -1,7 +1,10 @@
 use std::str::FromStr;
 
 use crate::{
-    commands::{Command, RequestParserError, ResponseParserError},
+    commands::{
+        Command, RequestParserError, ResponseParserError, empty_command_response,
+        single_item_command_request,
+    },
     common::types::VolumeValue,
     request_tokenizer::RequestTokenizer,
     response_tokenizer::ResponseAttributes,
@@ -9,31 +12,11 @@ use crate::{
 
 pub struct SetVol;
 
-impl Command for SetVol {
-    type Request = VolumeValue;
-    type Response = ();
-    const COMMAND: &'static str = "setvol";
+single_item_command_request!(SetVol, "setvol", VolumeValue);
 
-    fn serialize_request(&self, request: Self::Request) -> String {
-        format!("{} {}", Self::COMMAND, request)
-    }
+empty_command_response!(SetVol);
 
-    fn parse_request(mut parts: RequestTokenizer<'_>) -> Result<Self::Request, RequestParserError> {
-        let volume = match parts.next() {
-            Some(s) => VolumeValue::from_str(s)
-                .map_err(|_| RequestParserError::SyntaxError(0, s.to_owned()))?,
-            None => return Err(RequestParserError::UnexpectedEOF),
-        };
-
-        debug_assert!(parts.next().is_none());
-
-        Ok(volume)
-    }
-
-    fn parse_response(
-        parts: ResponseAttributes<'_>,
-    ) -> Result<Self::Response, ResponseParserError<'_>> {
-        debug_assert!(parts.is_empty());
-        Ok(())
-    }
+impl Command<'_, '_> for SetVol {
+    type Request = SetVolRequest;
+    type Response = SetVolResponse;
 }

src/commands/playback_options/single.rs

@@ -1,7 +1,10 @@
 use std::str::FromStr;
 
 use crate::{
-    commands::{Command, RequestParserError, ResponseParserError},
+    commands::{
+        Command, RequestParserError, ResponseParserError, empty_command_response,
+        single_item_command_request,
+    },
     common::types::BoolOrOneshot,
     request_tokenizer::RequestTokenizer,
     response_tokenizer::ResponseAttributes,
@@ -9,31 +12,11 @@ use crate::{
 
 pub struct Single;
 
-impl Command for Single {
-    type Request = BoolOrOneshot;
-    type Response = ();
-    const COMMAND: &'static str = "single";
+single_item_command_request!(Single, "single", BoolOrOneshot);
 
-    fn serialize_request(&self, request: Self::Request) -> String {
-        format!("{} {}", Self::COMMAND, request)
-    }
+empty_command_response!(Single);
 
-    fn parse_request(mut parts: RequestTokenizer<'_>) -> Result<Self::Request, RequestParserError> {
-        let state = match parts.next() {
-            Some(s) => crate::common::types::BoolOrOneshot::from_str(s)
-                .map_err(|_| RequestParserError::SyntaxError(0, s.to_owned()))?,
-            None => return Err(RequestParserError::UnexpectedEOF),
-        };
-
-        debug_assert!(parts.next().is_none());
-
-        Ok(state)
-    }
-
-    fn parse_response(
-        parts: ResponseAttributes<'_>,
-    ) -> Result<Self::Response, ResponseParserError<'_>> {
-        debug_assert!(parts.is_empty());
-        Ok(())
-    }
+impl Command<'_, '_> for Single {
+    type Request = SingleRequest;
+    type Response = SingleResponse;
 }

src/commands/playback_options/volume.rs

@@ -1,7 +1,10 @@
 use std::str::FromStr;
 
 use crate::{
-    commands::{Command, RequestParserError, ResponseParserError},
+    commands::{
+        Command, RequestParserError, ResponseParserError, empty_command_response,
+        single_item_command_request,
+    },
     common::types::VolumeValue,
     request_tokenizer::RequestTokenizer,
     response_tokenizer::ResponseAttributes,
@@ -9,31 +12,11 @@ use crate::{
 
 pub struct Volume;
 
-impl Command for Volume {
-    type Request = VolumeValue;
-    type Response = ();
-    const COMMAND: &'static str = "volume";
+single_item_command_request!(Volume, "volume", VolumeValue);
 
-    fn serialize_request(&self, request: Self::Request) -> String {
-        format!("{} {}", Self::COMMAND, request)
-    }
+empty_command_response!(Volume);
 
-    fn parse_request(mut parts: RequestTokenizer<'_>) -> Result<Self::Request, RequestParserError> {
-        let change = match parts.next() {
-            Some(s) => VolumeValue::from_str(s)
-                .map_err(|_| RequestParserError::SyntaxError(0, s.to_owned()))?,
-            None => return Err(RequestParserError::UnexpectedEOF),
-        };
-
-        debug_assert!(parts.next().is_none());
-
-        Ok(change)
-    }
-
-    fn parse_response(
-        parts: ResponseAttributes<'_>,
-    ) -> Result<Self::Response, ResponseParserError<'_>> {
-        debug_assert!(parts.is_empty());
-        Ok(())
-    }
+impl Command<'_, '_> for Volume {
+    type Request = VolumeRequest;
+    type Response = VolumeResponse;
 }

src/commands/querying_mpd_status/clearerror.rs

@@ -1,5 +1,8 @@
 use crate::{
-    commands::{Command, RequestParserError, ResponseParserError},
+    commands::{
+        Command, CommandRequest, RequestParserError, ResponseParserError, empty_command_request,
+        empty_command_response,
+    },
     request_tokenizer::RequestTokenizer,
     response_tokenizer::ResponseAttributes,
 };
@@ -7,25 +10,11 @@ use crate::{
 /// Clears the current error message in status (this is also accomplished by any command that starts playback)
 pub struct ClearError;
 
-impl Command for ClearError {
-    type Request = ();
-    type Response = ();
-    const COMMAND: &'static str = "clearerror";
+empty_command_request!(ClearError, "clearerror");
 
-    fn serialize_request(&self, _request: Self::Request) -> String {
-        Self::COMMAND.to_string()
-    }
+empty_command_response!(ClearError);
 
-    fn parse_request(mut parts: RequestTokenizer<'_>) -> Result<Self::Request, RequestParserError> {
-        debug_assert!(parts.next().is_none());
-
-        Ok(())
-    }
-
-    fn parse_response(
-        parts: ResponseAttributes<'_>,
-    ) -> Result<Self::Response, ResponseParserError<'_>> {
-        debug_assert!(parts.is_empty());
-        Ok(())
-    }
+impl Command<'_, '_> for ClearError {
+    type Request = ClearErrorRequest;
+    type Response = ClearErrorResponse;
 }

src/commands/querying_mpd_status/currentsong.rs

@@ -1,7 +1,9 @@
 use serde::{Deserialize, Serialize};
 
 use crate::{
-    commands::{Command, RequestParserError, ResponseParserError},
+    commands::{
+        Command, CommandResponse, RequestParserError, ResponseParserError, empty_command_request,
+    },
     request_tokenizer::RequestTokenizer,
     response_tokenizer::ResponseAttributes,
 };
@@ -9,27 +11,26 @@ use crate::{
 /// Displays the song info of the current song (same song that is identified in status)
 pub struct CurrentSong;
 
+empty_command_request!(CurrentSong, "currentsong");
+
 #[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
 pub struct CurrentSongResponse {}
 
-impl Command for CurrentSong {
-    type Request = ();
-    type Response = CurrentSongResponse;
-    const COMMAND: &'static str = "currentsong";
-
-    fn serialize_request(&self, _request: Self::Request) -> String {
-        Self::COMMAND.to_string()
+impl CommandResponse<'_> for CurrentSongResponse {
+    fn into_response_enum(self) -> crate::Response {
+        todo!()
     }
 
-    fn parse_request(mut parts: RequestTokenizer<'_>) -> Result<Self::Request, RequestParserError> {
-        debug_assert!(parts.next().is_none());
-
-        Ok(())
+    fn from_response_enum(response: crate::Response) -> Option<Self> {
+        todo!()
     }
 
-    fn parse_response(
-        _parts: ResponseAttributes<'_>,
-    ) -> Result<Self::Response, ResponseParserError<'_>> {
+    fn parse(parts: ResponseAttributes<'_>) -> Result<Self, ResponseParserError<'_>> {
         unimplemented!()
     }
 }
+
+impl Command<'_, '_> for CurrentSong {
+    type Request = CurrentSongRequest;
+    type Response = CurrentSongResponse;
+}

src/commands/querying_mpd_status/idle.rs

@@ -1,7 +1,9 @@
 use std::str::FromStr;
 
 use crate::{
-    commands::{Command, RequestParserError, ResponseParserError},
+    commands::{
+        Command, CommandRequest, RequestParserError, ResponseParserError, empty_command_response,
+    },
     common::types::SubSystem,
     request_tokenizer::RequestTokenizer,
     response_tokenizer::ResponseAttributes,
@@ -9,15 +11,24 @@ use crate::{
 
 pub struct Idle;
 
-pub type IdleRequest = Option<Vec<SubSystem>>;
+pub struct IdleRequest(Option<Vec<SubSystem>>);
 
-impl Command for Idle {
-    type Request = IdleRequest;
-    type Response = ();
+impl CommandRequest<'_> for IdleRequest {
     const COMMAND: &'static str = "idle";
 
-    fn serialize_request(&self, request: Self::Request) -> String {
+    fn into_request_enum(self) -> crate::Request {
+        crate::Request::Idle(self.0)
+    }
+
+    fn from_request_enum(request: crate::Request) -> Option<Self> {
         match request {
+            crate::Request::Idle(subsystems) => Some(IdleRequest(subsystems)),
+            _ => None,
+        }
+    }
+
+    fn serialize(&self) -> String {
+        match &self.0 {
             Some(subsystems) => {
                 let subsystems_str = subsystems
                     .iter()
@@ -30,7 +41,8 @@ impl Command for Idle {
         }
     }
 
-    fn parse_request(mut parts: RequestTokenizer<'_>) -> Result<Self::Request, RequestParserError> {
+    fn parse(parts: RequestTokenizer<'_>) -> Result<Self, RequestParserError> {
+        let mut parts = parts;
         let result = parts.next().map_or(Ok(None), |subsystems| {
             let subsystems = subsystems
                 .split(',')
@@ -41,13 +53,13 @@ impl Command for Idle {
 
         debug_assert!(parts.next().is_none());
 
-        result
-    }
-
-    fn parse_response(
-        parts: ResponseAttributes<'_>,
-    ) -> Result<Self::Response, ResponseParserError<'_>> {
-        debug_assert!(parts.is_empty());
-        Ok(())
+        result.map(IdleRequest)
     }
 }
+
+empty_command_response!(Idle);
+
+impl Command<'_, '_> for Idle {
+    type Request = IdleRequest;
+    type Response = IdleResponse;
+}

src/commands/querying_mpd_status/stats.rs

@@ -3,7 +3,9 @@ use std::collections::HashMap;
 use serde::{Deserialize, Serialize};
 
 use crate::{
-    commands::{Command, RequestParserError, ResponseParserError},
+    commands::{
+        Command, CommandResponse, RequestParserError, ResponseParserError, empty_command_request,
+    },
     request_tokenizer::RequestTokenizer,
     response_tokenizer::{
         ResponseAttributes, get_and_parse_optional_property, get_and_parse_property,
@@ -12,6 +14,8 @@ use crate::{
 
 pub struct Stats;
 
+empty_command_request!(Stats, "stats");
+
 #[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
 pub struct StatsResponse {
     pub uptime: u64,
@@ -23,24 +27,16 @@ pub struct StatsResponse {
     pub db_update: Option<u64>,
 }
 
-impl Command for Stats {
-    type Request = ();
-    type Response = StatsResponse;
-    const COMMAND: &'static str = "stats";
-
-    fn serialize_request(&self, _: Self::Request) -> String {
-        Self::COMMAND.to_string()
+impl CommandResponse<'_> for StatsResponse {
+    fn into_response_enum(self) -> crate::Response {
+        todo!()
     }
 
-    fn parse_request(mut parts: RequestTokenizer<'_>) -> Result<Self::Request, RequestParserError> {
-        debug_assert!(parts.next().is_none());
-
-        Ok(())
+    fn from_response_enum(response: crate::Response) -> Option<Self> {
+        todo!()
     }
 
-    fn parse_response(
-        parts: ResponseAttributes<'_>,
-    ) -> Result<Self::Response, ResponseParserError<'_>> {
+    fn parse(parts: ResponseAttributes<'_>) -> Result<Self, ResponseParserError<'_>> {
         let parts: HashMap<_, _> = parts.into_map()?;
 
         let uptime = get_and_parse_property!(parts, "uptime", Text);
@@ -62,3 +58,8 @@ impl Command for Stats {
         })
     }
 }
+
+impl Command<'_, '_> for Stats {
+    type Request = StatsRequest;
+    type Response = StatsResponse;
+}

src/commands/querying_mpd_status/status.rs

@@ -4,7 +4,9 @@ use std::str::FromStr;
 use serde::{Deserialize, Serialize};
 
 use crate::{
-    commands::{Command, RequestParserError, ResponseParserError},
+    commands::{
+        Command, CommandResponse, RequestParserError, ResponseParserError, empty_command_request,
+    },
     common::types::{Audio, BoolOrOneshot, SongId, SongPosition},
     request_tokenizer::RequestTokenizer,
     response_tokenizer::{
@@ -13,6 +15,10 @@ use crate::{
     },
 };
 
+pub struct Status;
+
+empty_command_request!(Status, "status");
+
 #[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
 pub enum StatusResponseState {
     Play,
@@ -62,124 +68,114 @@ pub struct StatusResponse {
     pub last_loaded_playlist: Option<String>,
 }
 
-#[inline]
-fn parse_status_response(
-    parts: ResponseAttributes<'_>,
-) -> Result<StatusResponse, ResponseParserError<'_>> {
-    let parts: HashMap<_, _> = parts.into_map()?;
-    let partition = get_property!(parts, "partition", Text).to_string();
+impl CommandResponse<'_> for StatusResponse {
+    fn into_response_enum(self) -> crate::Response {
+        todo!()
+    }
 
-    let volume = match get_property!(parts, "volume", Text) {
-        "-1" => None,
-        volume => Some(
-            volume
-                .parse()
-                .map_err(|_| ResponseParserError::InvalidProperty("volume", volume))?,
-        ),
-    };
+    fn from_response_enum(response: crate::Response) -> Option<Self> {
+        todo!()
+    }
 
-    let repeat = match get_property!(parts, "repeat", Text) {
-        "0" => Ok(false),
-        "1" => Ok(true),
-        repeat => Err(ResponseParserError::InvalidProperty("repeat", repeat)),
-    }?;
+    fn parse(parts: ResponseAttributes<'_>) -> Result<Self, ResponseParserError<'_>> {
+        let parts: HashMap<_, _> = parts.into_map()?;
+        let partition = get_property!(parts, "partition", Text).to_string();
 
-    let random = match get_property!(parts, "random", Text) {
-        "0" => Ok(false),
-        "1" => Ok(true),
-        random => Err(ResponseParserError::InvalidProperty("random", random)),
-    }?;
+        let volume = match get_property!(parts, "volume", Text) {
+            "-1" => None,
+            volume => Some(
+                volume
+                    .parse()
+                    .map_err(|_| ResponseParserError::InvalidProperty("volume", volume))?,
+            ),
+        };
 
-    let single = get_and_parse_property!(parts, "single", Text);
-    let consume = get_and_parse_property!(parts, "consume", Text);
-    let playlist: u32 = get_and_parse_property!(parts, "playlist", Text);
-    let playlist_length: u64 = get_and_parse_property!(parts, "playlistlength", Text);
-    let state: StatusResponseState = get_and_parse_property!(parts, "state", Text);
-    let song: Option<SongPosition> = get_and_parse_optional_property!(parts, "song", Text);
-    let song_id: Option<SongId> = get_and_parse_optional_property!(parts, "songid", Text);
-    let next_song: Option<SongPosition> = get_and_parse_optional_property!(parts, "nextsong", Text);
-    let next_song_id: Option<SongId> = get_and_parse_optional_property!(parts, "nextsongid", Text);
+        let repeat = match get_property!(parts, "repeat", Text) {
+            "0" => Ok(false),
+            "1" => Ok(true),
+            repeat => Err(ResponseParserError::InvalidProperty("repeat", repeat)),
+        }?;
 
-    let time = match get_optional_property!(parts, "time", Text) {
-        Some(time) => {
-            let mut parts = time.split(':');
-            let elapsed = parts
-                .next()
-                .ok_or(ResponseParserError::SyntaxError(0, time))?
-                .parse()
-                .map_err(|_| ResponseParserError::InvalidProperty("time", time))?;
-            let duration = parts
-                .next()
-                .ok_or(ResponseParserError::SyntaxError(0, time))?
-                .parse()
-                .map_err(|_| ResponseParserError::InvalidProperty("time", time))?;
-            Some((elapsed, duration))
-        }
-        None => None,
-    };
+        let random = match get_property!(parts, "random", Text) {
+            "0" => Ok(false),
+            "1" => Ok(true),
+            random => Err(ResponseParserError::InvalidProperty("random", random)),
+        }?;
 
-    let elapsed = get_and_parse_optional_property!(parts, "elapsed", Text);
-    let duration = get_and_parse_optional_property!(parts, "duration", Text);
-    let bitrate = get_and_parse_optional_property!(parts, "bitrate", Text);
-    let xfade = get_and_parse_optional_property!(parts, "xfade", Text);
-    let mixrampdb = get_and_parse_optional_property!(parts, "mixrampdb", Text);
-    let mixrampdelay = get_and_parse_optional_property!(parts, "mixrampdelay", Text);
-    let audio = get_and_parse_optional_property!(parts, "audio", Text);
-    let updating_db = get_and_parse_optional_property!(parts, "updating_db", Text);
-    let error = get_and_parse_optional_property!(parts, "error", Text);
-    let last_loaded_playlist =
-        get_and_parse_optional_property!(parts, "last_loaded_playlist", Text);
+        let single = get_and_parse_property!(parts, "single", Text);
+        let consume = get_and_parse_property!(parts, "consume", Text);
+        let playlist: u32 = get_and_parse_property!(parts, "playlist", Text);
+        let playlist_length: u64 = get_and_parse_property!(parts, "playlistlength", Text);
+        let state: StatusResponseState = get_and_parse_property!(parts, "state", Text);
+        let song: Option<SongPosition> = get_and_parse_optional_property!(parts, "song", Text);
+        let song_id: Option<SongId> = get_and_parse_optional_property!(parts, "songid", Text);
+        let next_song: Option<SongPosition> =
+            get_and_parse_optional_property!(parts, "nextsong", Text);
+        let next_song_id: Option<SongId> =
+            get_and_parse_optional_property!(parts, "nextsongid", Text);
 
-    Ok(StatusResponse {
-        partition,
-        volume,
-        repeat,
-        random,
-        single,
-        consume,
-        playlist,
-        playlist_length,
-        state,
-        song,
-        song_id,
-        next_song,
-        next_song_id,
-        time,
-        elapsed,
-        duration,
-        bitrate,
-        xfade,
-        mixrampdb,
-        mixrampdelay,
-        audio,
-        updating_db,
-        error,
-        last_loaded_playlist,
-    })
+        let time = match get_optional_property!(parts, "time", Text) {
+            Some(time) => {
+                let mut parts = time.split(':');
+                let elapsed = parts
+                    .next()
+                    .ok_or(ResponseParserError::SyntaxError(0, time))?
+                    .parse()
+                    .map_err(|_| ResponseParserError::InvalidProperty("time", time))?;
+                let duration = parts
+                    .next()
+                    .ok_or(ResponseParserError::SyntaxError(0, time))?
+                    .parse()
+                    .map_err(|_| ResponseParserError::InvalidProperty("time", time))?;
+                Some((elapsed, duration))
+            }
+            None => None,
+        };
+
+        let elapsed = get_and_parse_optional_property!(parts, "elapsed", Text);
+        let duration = get_and_parse_optional_property!(parts, "duration", Text);
+        let bitrate = get_and_parse_optional_property!(parts, "bitrate", Text);
+        let xfade = get_and_parse_optional_property!(parts, "xfade", Text);
+        let mixrampdb = get_and_parse_optional_property!(parts, "mixrampdb", Text);
+        let mixrampdelay = get_and_parse_optional_property!(parts, "mixrampdelay", Text);
+        let audio = get_and_parse_optional_property!(parts, "audio", Text);
+        let updating_db = get_and_parse_optional_property!(parts, "updating_db", Text);
+        let error = get_and_parse_optional_property!(parts, "error", Text);
+        let last_loaded_playlist =
+            get_and_parse_optional_property!(parts, "last_loaded_playlist", Text);
+
+        Ok(StatusResponse {
+            partition,
+            volume,
+            repeat,
+            random,
+            single,
+            consume,
+            playlist,
+            playlist_length,
+            state,
+            song,
+            song_id,
+            next_song,
+            next_song_id,
+            time,
+            elapsed,
+            duration,
+            bitrate,
+            xfade,
+            mixrampdb,
+            mixrampdelay,
+            audio,
+            updating_db,
+            error,
+            last_loaded_playlist,
+        })
+    }
 }
 
-pub struct Status;
-
-impl Command for Status {
-    type Request = ();
+impl Command<'_, '_> for Status {
+    type Request = StatusRequest;
     type Response = StatusResponse;
-    const COMMAND: &'static str = "status";
-
-    fn serialize_request(&self, _request: Self::Request) -> String {
-        Self::COMMAND.to_string()
-    }
-
-    fn parse_request(mut parts: RequestTokenizer<'_>) -> Result<Self::Request, RequestParserError> {
-        debug_assert!(parts.next().is_none());
-
-        Ok(())
-    }
-
-    fn parse_response(
-        parts: ResponseAttributes<'_>,
-    ) -> Result<Self::Response, ResponseParserError<'_>> {
-        parse_status_response(parts)
-    }
 }
 
 #[cfg(test)]
@@ -214,7 +210,7 @@ mod tests {
         "# };
 
         assert_eq!(
-            Status::parse_raw_response(contents),
+            Status::parse_raw_response(contents.as_bytes()),
             Ok(StatusResponse {
                 partition: "default".into(),
                 volume: Some(66),

src/commands/queue/add.rs

@@ -1,7 +1,9 @@
 use serde::{Deserialize, Serialize};
 
 use crate::{
-    commands::{Command, RequestParserError, ResponseParserError},
+    commands::{
+        Command, CommandRequest, RequestParserError, ResponseParserError, empty_command_response,
+    },
     common::types::{SongPosition, Uri},
     request_tokenizer::RequestTokenizer,
     response_tokenizer::ResponseAttributes,
@@ -15,25 +17,28 @@ pub struct AddRequest {
     position: Option<SongPosition>,
 }
 
-impl AddRequest {
-    pub fn new(uri: Uri, position: Option<SongPosition>) -> Self {
-        Self { uri, position }
-    }
-}
-
-impl Command for Add {
-    type Request = AddRequest;
-    type Response = ();
+impl CommandRequest<'_> for AddRequest {
     const COMMAND: &'static str = "add";
 
-    fn serialize_request(&self, request: Self::Request) -> String {
-        match request.position {
-            Some(position) => format!("{} {} {}", Self::COMMAND, request.uri, position),
-            None => format!("{} {}", Self::COMMAND, request.uri),
+    fn into_request_enum(self) -> crate::Request {
+        crate::Request::Add(self.uri, self.position)
+    }
+
+    fn from_request_enum(request: crate::Request) -> Option<Self> {
+        match request {
+            crate::Request::Add(uri, position) => Some(AddRequest { uri, position }),
+            _ => None,
         }
     }
 
-    fn parse_request(mut parts: RequestTokenizer<'_>) -> Result<Self::Request, RequestParserError> {
+    fn serialize(&self) -> String {
+        match self.position {
+            Some(position) => format!("{} {} {}", Self::COMMAND, self.uri, position),
+            None => format!("{} {}", Self::COMMAND, self.uri),
+        }
+    }
+
+    fn parse(mut parts: RequestTokenizer<'_>) -> Result<Self, RequestParserError> {
         let uri = match parts.next() {
             Some(s) => s,
             None => return Err(RequestParserError::UnexpectedEOF),
@@ -54,11 +59,11 @@ impl Command for Add {
             position,
         })
     }
-
-    fn parse_response(
-        parts: ResponseAttributes<'_>,
-    ) -> Result<Self::Response, ResponseParserError<'_>> {
-        debug_assert!(parts.is_empty());
-        Ok(())
-    }
+}
+
+empty_command_response!(Add);
+
+impl Command<'_, '_> for Add {
+    type Request = AddRequest;
+    type Response = AddResponse;
 }

src/commands/queue/addid.rs

@@ -1,7 +1,7 @@
 use serde::{Deserialize, Serialize};
 
 use crate::{
-    commands::{Command, RequestParserError, ResponseParserError},
+    commands::{Command, CommandRequest, CommandResponse, RequestParserError, ResponseParserError},
     common::types::{SongId, SongPosition, Uri},
     request_tokenizer::RequestTokenizer,
     response_tokenizer::{ResponseAttributes, get_next_and_parse_property},
@@ -15,24 +15,28 @@ pub struct AddIdRequest {
     pub position: Option<SongPosition>,
 }
 
-#[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
-pub struct AddIdResponse {
-    pub id: SongId,
-}
-
-impl Command for AddId {
-    type Request = AddIdRequest;
-    type Response = AddIdResponse;
+impl CommandRequest<'_> for AddIdRequest {
     const COMMAND: &'static str = "addid";
 
-    fn serialize_request(&self, request: Self::Request) -> String {
-        match request.position {
-            Some(pos) => format!("{} {} {}", Self::COMMAND, request.uri, pos),
-            None => format!("{} {}", Self::COMMAND, request.uri),
+    fn into_request_enum(self) -> crate::Request {
+        crate::Request::AddId(self.uri, self.position)
+    }
+
+    fn from_request_enum(request: crate::Request) -> Option<Self> {
+        match request {
+            crate::Request::AddId(uri, position) => Some(AddIdRequest { uri, position }),
+            _ => None,
         }
     }
 
-    fn parse_request(mut parts: RequestTokenizer<'_>) -> Result<Self::Request, RequestParserError> {
+    fn serialize(&self) -> String {
+        match self.position {
+            Some(pos) => format!("{} {} {}", Self::COMMAND, self.uri, pos),
+            None => format!("{} {}", Self::COMMAND, self.uri),
+        }
+    }
+
+    fn parse(mut parts: RequestTokenizer<'_>) -> Result<Self, RequestParserError> {
         let uri = match parts.next() {
             Some(s) => s,
             None => return Err(RequestParserError::UnexpectedEOF),
@@ -53,10 +57,23 @@ impl Command for AddId {
             position,
         })
     }
+}
 
-    fn parse_response(
-        parts: ResponseAttributes<'_>,
-    ) -> Result<Self::Response, ResponseParserError<'_>> {
+#[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
+pub struct AddIdResponse {
+    pub id: SongId,
+}
+
+impl CommandResponse<'_> for AddIdResponse {
+    fn into_response_enum(self) -> crate::Response {
+        todo!()
+    }
+
+    fn from_response_enum(response: crate::Response) -> Option<Self> {
+        todo!()
+    }
+
+    fn parse(parts: ResponseAttributes<'_>) -> Result<Self, ResponseParserError<'_>> {
         let parts: Vec<_> = parts.into();
         let mut iter = parts.into_iter();
         let (key, id) = get_next_and_parse_property!(iter, Text);
@@ -66,3 +83,8 @@ impl Command for AddId {
         Ok(AddIdResponse { id })
     }
 }
+
+impl Command<'_, '_> for AddId {
+    type Request = AddIdRequest;
+    type Response = AddIdResponse;
+}

src/commands/queue/addtagid.rs

@@ -1,7 +1,10 @@
 use serde::{Deserialize, Serialize};
 
 use crate::{
-    commands::{Command, RequestParserError, ResponseAttributes, ResponseParserError},
+    commands::{
+        Command, CommandRequest, RequestParserError, ResponseAttributes, ResponseParserError,
+        empty_command_response,
+    },
     common::types::{SongId, TagName, TagValue},
     request_tokenizer::RequestTokenizer,
 };
@@ -15,22 +18,35 @@ pub struct AddTagIdRequest {
     pub tag_value: TagValue,
 }
 
-impl Command for AddTagId {
-    type Request = AddTagIdRequest;
-    type Response = ();
+impl CommandRequest<'_> for AddTagIdRequest {
     const COMMAND: &'static str = "addtagid";
 
-    fn serialize_request(&self, request: Self::Request) -> String {
+    fn into_request_enum(self) -> crate::Request {
+        crate::Request::AddTagId(self.songid, self.tag_name, self.tag_value)
+    }
+
+    fn from_request_enum(request: crate::Request) -> Option<Self> {
+        match request {
+            crate::Request::AddTagId(songid, tag_name, tag_value) => Some(AddTagIdRequest {
+                songid,
+                tag_name,
+                tag_value,
+            }),
+            _ => None,
+        }
+    }
+
+    fn serialize(&self) -> String {
         format!(
             "{} {} {} {}",
             Self::COMMAND,
-            request.songid,
-            request.tag_name,
-            request.tag_value
+            self.songid,
+            self.tag_name,
+            self.tag_value
         )
     }
 
-    fn parse_request(mut parts: RequestTokenizer<'_>) -> Result<Self::Request, RequestParserError> {
+    fn parse(mut parts: RequestTokenizer<'_>) -> Result<Self, RequestParserError> {
         let songid = parts.next().ok_or(RequestParserError::UnexpectedEOF)?;
         let songid = songid
             .parse()
@@ -54,11 +70,11 @@ impl Command for AddTagId {
             tag_value,
         })
     }
-
-    fn parse_response(
-        parts: ResponseAttributes<'_>,
-    ) -> Result<Self::Response, ResponseParserError<'_>> {
-        debug_assert!(parts.is_empty());
-        Ok(())
-    }
+}
+
+empty_command_response!(AddTagId);
+
+impl Command<'_, '_> for AddTagId {
+    type Request = AddTagIdRequest;
+    type Response = AddTagIdResponse;
 }

src/commands/queue/clear.rs

@@ -1,29 +1,19 @@
 use crate::{
-    commands::{Command, RequestParserError, ResponseParserError},
+    commands::{
+        Command, RequestParserError, ResponseParserError, empty_command_request,
+        empty_command_response,
+    },
     request_tokenizer::RequestTokenizer,
     response_tokenizer::ResponseAttributes,
 };
 
 pub struct Clear;
 
-impl Command for Clear {
-    type Request = ();
-    type Response = ();
-    const COMMAND: &'static str = "clear";
+empty_command_request!(Clear, "clear");
 
-    fn serialize_request(&self, _request: Self::Request) -> String {
-        Self::COMMAND.to_string()
-    }
+empty_command_response!(Clear);
 
-    fn parse_request(mut parts: RequestTokenizer<'_>) -> Result<Self::Request, RequestParserError> {
-        debug_assert!(parts.next().is_none());
-        Ok(())
-    }
-
-    fn parse_response(
-        parts: ResponseAttributes<'_>,
-    ) -> Result<Self::Response, ResponseParserError<'_>> {
-        debug_assert!(parts.is_empty());
-        Ok(())
-    }
+impl Command<'_, '_> for Clear {
+    type Request = ClearRequest;
+    type Response = ClearResponse;
 }

src/commands/queue/cleartagid.rs

@@ -1,7 +1,9 @@
 use serde::{Deserialize, Serialize};
 
 use crate::{
-    commands::{Command, RequestParserError, ResponseParserError},
+    commands::{
+        Command, CommandRequest, RequestParserError, ResponseParserError, empty_command_response,
+    },
     common::types::{SongId, TagName},
     request_tokenizer::RequestTokenizer,
     response_tokenizer::ResponseAttributes,
@@ -15,16 +17,27 @@ pub struct ClearTagIdRequest {
     pub tag_name: TagName,
 }
 
-impl Command for ClearTagId {
-    type Request = ClearTagIdRequest;
-    type Response = ();
+impl CommandRequest<'_> for ClearTagIdRequest {
     const COMMAND: &'static str = "cleartagid";
 
-    fn serialize_request(&self, request: Self::Request) -> String {
-        format!("{} {} {}", Self::COMMAND, request.songid, request.tag_name)
+    fn into_request_enum(self) -> crate::Request {
+        crate::Request::ClearTagId(self.songid, self.tag_name)
     }
 
-    fn parse_request(mut parts: RequestTokenizer<'_>) -> Result<Self::Request, RequestParserError> {
+    fn from_request_enum(request: crate::Request) -> Option<Self> {
+        match request {
+            crate::Request::ClearTagId(songid, tag_name) => {
+                Some(ClearTagIdRequest { songid, tag_name })
+            }
+            _ => None,
+        }
+    }
+
+    fn serialize(&self) -> String {
+        format!("{} {} {}", Self::COMMAND, self.songid, self.tag_name)
+    }
+
+    fn parse(mut parts: RequestTokenizer<'_>) -> Result<Self, RequestParserError> {
         let songid = parts.next().ok_or(RequestParserError::UnexpectedEOF)?;
         let songid = songid
             .parse()
@@ -39,11 +52,11 @@ impl Command for ClearTagId {
 
         Ok(ClearTagIdRequest { songid, tag_name })
     }
-
-    fn parse_response(
-        parts: ResponseAttributes<'_>,
-    ) -> Result<Self::Response, ResponseParserError<'_>> {
-        debug_assert!(parts.is_empty());
-        Ok(())
-    }
+}
+
+empty_command_response!(ClearTagId);
+
+impl Command<'_, '_> for ClearTagId {
+    type Request = ClearTagIdRequest;
+    type Response = ClearTagIdResponse;
 }

src/commands/queue/delete.rs

@@ -1,7 +1,10 @@
 use std::str::FromStr;
 
 use crate::{
-    commands::{Command, RequestParserError, ResponseParserError},
+    commands::{
+        Command, RequestParserError, ResponseParserError, empty_command_response,
+        single_item_command_request,
+    },
     common::types::OneOrRange,
     request_tokenizer::RequestTokenizer,
     response_tokenizer::ResponseAttributes,
@@ -9,29 +12,11 @@ use crate::{
 
 pub struct Delete;
 
-impl Command for Delete {
-    type Request = OneOrRange;
-    type Response = ();
-    const COMMAND: &'static str = "delete";
+single_item_command_request!(Delete, "delete", OneOrRange);
 
-    fn serialize_request(&self, request: Self::Request) -> String {
-        format!("{} {}", Self::COMMAND, request)
-    }
+empty_command_response!(Delete);
 
-    fn parse_request(mut parts: RequestTokenizer<'_>) -> Result<Self::Request, RequestParserError> {
-        let pos_or_range = parts.next().ok_or(RequestParserError::UnexpectedEOF)?;
-        let one_or_range = OneOrRange::from_str(pos_or_range)
-            .map_err(|_| RequestParserError::SyntaxError(0, pos_or_range.to_string()))?;
-
-        debug_assert!(parts.next().is_none());
-
-        Ok(one_or_range)
-    }
-
-    fn parse_response(
-        parts: ResponseAttributes<'_>,
-    ) -> Result<Self::Response, ResponseParserError<'_>> {
-        debug_assert!(parts.is_empty());
-        Ok(())
-    }
+impl Command<'_, '_> for Delete {
+    type Request = DeleteRequest;
+    type Response = DeleteResponse;
 }

src/commands/queue/deleteid.rs

@@ -1,5 +1,8 @@
 use crate::{
-    commands::{Command, RequestParserError, ResponseParserError},
+    commands::{
+        Command, RequestParserError, ResponseParserError, empty_command_response,
+        single_item_command_request,
+    },
     common::types::SongId,
     request_tokenizer::RequestTokenizer,
     response_tokenizer::ResponseAttributes,
@@ -7,30 +10,11 @@ use crate::{
 
 pub struct DeleteId;
 
-impl Command for DeleteId {
-    type Request = SongId;
-    type Response = ();
-    const COMMAND: &'static str = "deleteid";
+single_item_command_request!(DeleteId, "deleteid", SongId);
 
-    fn serialize_request(&self, request: Self::Request) -> String {
-        format!("{} {}", Self::COMMAND, request)
-    }
+empty_command_response!(DeleteId);
 
-    fn parse_request(mut parts: RequestTokenizer<'_>) -> Result<Self::Request, RequestParserError> {
-        let id = parts.next().ok_or(RequestParserError::UnexpectedEOF)?;
-        let id = id
-            .parse()
-            .map_err(|_| RequestParserError::SyntaxError(0, id.to_string()))?;
-
-        debug_assert!(parts.next().is_none());
-
-        Ok(id)
-    }
-
-    fn parse_response(
-        parts: ResponseAttributes<'_>,
-    ) -> Result<Self::Response, ResponseParserError<'_>> {
-        debug_assert!(parts.is_empty());
-        Ok(())
-    }
+impl Command<'_, '_> for DeleteId {
+    type Request = DeleteIdRequest;
+    type Response = DeleteIdResponse;
 }

src/commands/queue/move_.rs

@@ -1,7 +1,10 @@
 use serde::{Deserialize, Serialize};
 
 use crate::{
-    commands::{Command, RequestParserError, ResponseAttributes, ResponseParserError},
+    commands::{
+        Command, CommandRequest, RequestParserError, ResponseAttributes, ResponseParserError,
+        empty_command_response,
+    },
     common::types::{AbsouluteRelativeSongPosition, OneOrRange},
     request_tokenizer::RequestTokenizer,
 };
@@ -14,16 +17,25 @@ pub struct MoveRequest {
     pub to: AbsouluteRelativeSongPosition,
 }
 
-impl Command for Move {
-    type Request = MoveRequest;
-    type Response = ();
+impl CommandRequest<'_> for MoveRequest {
     const COMMAND: &'static str = "move";
 
-    fn serialize_request(&self, request: Self::Request) -> String {
-        format!("{} {} {}", Self::COMMAND, request.from_or_range, request.to)
+    fn into_request_enum(self) -> crate::Request {
+        crate::Request::Move(self.from_or_range, self.to)
     }
 
-    fn parse_request(mut parts: RequestTokenizer<'_>) -> Result<Self::Request, RequestParserError> {
+    fn from_request_enum(request: crate::Request) -> Option<Self> {
+        match request {
+            crate::Request::Move(from_or_range, to) => Some(MoveRequest { from_or_range, to }),
+            _ => None,
+        }
+    }
+
+    fn serialize(&self) -> String {
+        format!("{} {} {}", Self::COMMAND, self.from_or_range, self.to)
+    }
+
+    fn parse(mut parts: RequestTokenizer<'_>) -> Result<Self, RequestParserError> {
         let from_or_range = parts.next().ok_or(RequestParserError::UnexpectedEOF)?;
         let from_or_range = from_or_range
             .parse()
@@ -38,11 +50,11 @@ impl Command for Move {
 
         Ok(MoveRequest { from_or_range, to })
     }
-
-    fn parse_response(
-        parts: ResponseAttributes<'_>,
-    ) -> Result<Self::Response, ResponseParserError<'_>> {
-        debug_assert!(parts.is_empty());
-        Ok(())
-    }
+}
+
+empty_command_response!(Move);
+
+impl Command<'_, '_> for Move {
+    type Request = MoveRequest;
+    type Response = MoveResponse;
 }

src/commands/queue/moveid.rs

@@ -1,7 +1,10 @@
 use serde::{Deserialize, Serialize};
 
 use crate::{
-    commands::{Command, RequestParserError, ResponseAttributes, ResponseParserError},
+    commands::{
+        Command, CommandRequest, RequestParserError, ResponseAttributes, ResponseParserError,
+        empty_command_response,
+    },
     common::types::{AbsouluteRelativeSongPosition, SongId},
     request_tokenizer::RequestTokenizer,
 };
@@ -14,16 +17,25 @@ pub struct MoveIdRequest {
     pub to: AbsouluteRelativeSongPosition,
 }
 
-impl Command for MoveId {
-    type Request = MoveIdRequest;
-    type Response = ();
+impl CommandRequest<'_> for MoveIdRequest {
     const COMMAND: &'static str = "moveid";
 
-    fn serialize_request(&self, request: Self::Request) -> String {
-        format!("{} {} {}", Self::COMMAND, request.id, request.to)
+    fn into_request_enum(self) -> crate::Request {
+        crate::Request::MoveId(self.id, self.to)
     }
 
-    fn parse_request(mut parts: RequestTokenizer<'_>) -> Result<Self::Request, RequestParserError> {
+    fn from_request_enum(request: crate::Request) -> Option<Self> {
+        match request {
+            crate::Request::MoveId(id, to) => Some(MoveIdRequest { id, to }),
+            _ => None,
+        }
+    }
+
+    fn serialize(&self) -> String {
+        format!("{} {} {}", Self::COMMAND, self.id, self.to)
+    }
+
+    fn parse(mut parts: RequestTokenizer<'_>) -> Result<Self, RequestParserError> {
         let id = parts.next().ok_or(RequestParserError::UnexpectedEOF)?;
         let id = id
             .parse()
@@ -38,11 +50,11 @@ impl Command for MoveId {
 
         Ok(MoveIdRequest { id, to })
     }
-
-    fn parse_response(
-        parts: ResponseAttributes<'_>,
-    ) -> Result<Self::Response, ResponseParserError<'_>> {
-        debug_assert!(parts.is_empty());
-        Ok(())
-    }
+}
+
+empty_command_response!(MoveId);
+
+impl Command<'_, '_> for MoveId {
+    type Request = MoveIdRequest;
+    type Response = MoveIdResponse;
 }

src/commands/queue/playlist.rs

@@ -1,28 +1,33 @@
 use crate::{
-    commands::{Command, RequestParserError, ResponseParserError},
+    commands::{
+        Command, CommandResponse, RequestParserError, ResponseParserError, empty_command_request,
+        single_item_command_request,
+    },
     request_tokenizer::RequestTokenizer,
     response_tokenizer::ResponseAttributes,
 };
 
 pub struct Playlist;
 
-impl Command for Playlist {
-    type Request = ();
-    type Response = ();
-    const COMMAND: &'static str = "playlist";
+empty_command_request!(Playlist, "playlist");
 
-    fn serialize_request(&self, _request: Self::Request) -> String {
-        Self::COMMAND.to_string()
+pub struct PlaylistResponse();
+
+impl CommandResponse<'_> for PlaylistResponse {
+    fn into_response_enum(self) -> crate::Response {
+        todo!()
     }
 
-    fn parse_request(mut parts: RequestTokenizer<'_>) -> Result<Self::Request, RequestParserError> {
-        debug_assert!(parts.next().is_none());
-        Ok(())
+    fn from_response_enum(response: crate::Response) -> Option<Self> {
+        todo!()
     }
 
-    fn parse_response(
-        _parts: ResponseAttributes<'_>,
-    ) -> Result<Self::Response, ResponseParserError<'_>> {
+    fn parse(parts: ResponseAttributes<'_>) -> Result<Self, ResponseParserError<'_>> {
         unimplemented!()
     }
 }
+
+impl Command<'_, '_> for Playlist {
+    type Request = PlaylistRequest;
+    type Response = PlaylistResponse;
+}

src/commands/queue/playlistfind.rs

@@ -1,7 +1,9 @@
 use serde::{Deserialize, Serialize};
 
 use crate::{
-    commands::{Command, RequestParserError, ResponseParserError},
+    commands::{
+        Command, CommandRequest, RequestParserError, ResponseParserError, empty_command_response,
+    },
     common::types::{Sort, WindowRange},
     filter::Filter,
     request_tokenizer::RequestTokenizer,
@@ -17,23 +19,36 @@ pub struct PlaylistFindRequest {
     window: Option<WindowRange>,
 }
 
-impl Command for PlaylistFind {
-    type Request = PlaylistFindRequest;
-    type Response = ();
+impl CommandRequest<'_> for PlaylistFindRequest {
     const COMMAND: &'static str = "playlistfind";
 
-    fn serialize_request(&self, request: Self::Request) -> String {
-        let mut cmd = format!("{} {}", Self::COMMAND, request.filter);
-        if let Some(sort) = request.sort {
+    fn into_request_enum(self) -> crate::Request {
+        crate::Request::PlaylistFind(self.filter, self.sort, self.window)
+    }
+
+    fn from_request_enum(request: crate::Request) -> Option<Self> {
+        match request {
+            crate::Request::PlaylistFind(filter, sort, window) => Some(PlaylistFindRequest {
+                filter,
+                sort,
+                window,
+            }),
+            _ => None,
+        }
+    }
+
+    fn serialize(&self) -> String {
+        let mut cmd = format!("{} {}", Self::COMMAND, self.filter);
+        if let Some(sort) = &self.sort {
             cmd.push_str(&format!(" sort {}", sort));
         }
-        if let Some(window) = request.window {
+        if let Some(window) = &self.window {
             cmd.push_str(&format!(" window {}", window));
         }
         cmd
     }
 
-    fn parse_request(mut parts: RequestTokenizer<'_>) -> Result<Self::Request, RequestParserError> {
+    fn parse(mut parts: RequestTokenizer<'_>) -> Result<Self, RequestParserError> {
         let filter = match parts.next() {
             Some(f) => {
                 Filter::parse(f).map_err(|_| RequestParserError::SyntaxError(1, f.to_owned()))?
@@ -69,10 +84,11 @@ impl Command for PlaylistFind {
             window,
         })
     }
-
-    fn parse_response(
-        _parts: ResponseAttributes<'_>,
-    ) -> Result<Self::Response, ResponseParserError<'_>> {
-        unimplemented!()
-    }
+}
+
+empty_command_response!(PlaylistFind);
+
+impl Command<'_, '_> for PlaylistFind {
+    type Request = PlaylistFindRequest;
+    type Response = PlaylistFindResponse;
 }

src/commands/queue/playlistid.rs

@@ -1,5 +1,8 @@
 use crate::{
-    commands::{Command, RequestParserError, ResponseParserError},
+    commands::{
+        Command, CommandResponse, RequestParserError, ResponseParserError,
+        single_item_command_request,
+    },
     common::types::SongId,
     request_tokenizer::RequestTokenizer,
     response_tokenizer::ResponseAttributes,
@@ -7,29 +10,25 @@ use crate::{
 
 pub struct PlaylistId;
 
-impl Command for PlaylistId {
-    type Request = SongId;
-    type Response = ();
-    const COMMAND: &'static str = "playlistid";
+single_item_command_request!(PlaylistId, "playlistid", SongId);
 
-    fn serialize_request(&self, request: Self::Request) -> String {
-        format!("{} {}", Self::COMMAND, request)
+pub struct PlaylistIdResponse();
+
+impl CommandResponse<'_> for PlaylistIdResponse {
+    fn into_response_enum(self) -> crate::Response {
+        todo!()
     }
 
-    fn parse_request(mut parts: RequestTokenizer<'_>) -> Result<Self::Request, RequestParserError> {
-        let id = parts.next().ok_or(RequestParserError::UnexpectedEOF)?;
-        let id = id
-            .parse()
-            .map_err(|_| RequestParserError::SyntaxError(0, id.to_string()))?;
-
-        debug_assert!(parts.next().is_none());
-
-        Ok(id)
+    fn from_response_enum(response: crate::Response) -> Option<Self> {
+        todo!()
     }
 
-    fn parse_response(
-        _parts: ResponseAttributes<'_>,
-    ) -> Result<Self::Response, ResponseParserError<'_>> {
+    fn parse(parts: ResponseAttributes<'_>) -> Result<Self, ResponseParserError<'_>> {
         unimplemented!()
     }
 }
+
+impl Command<'_, '_> for PlaylistId {
+    type Request = PlaylistIdRequest;
+    type Response = PlaylistIdResponse;
+}

src/commands/queue/playlistinfo.rs

@@ -7,7 +7,7 @@ use crate::{
 
 pub struct PlaylistInfo;
 
-impl Command for PlaylistInfo {
+impl Command<'_, '_> for PlaylistInfo {
     type Request = Option<OneOrRange>;
     type Response = ();
     const COMMAND: &'static str = "playlistinfo";

src/commands/queue/playlistsearch.rs

@@ -17,7 +17,7 @@ pub struct PlaylistSearchRequest {
     window: Option<WindowRange>,
 }
 
-impl Command for PlaylistSearch {
+impl Command<'_, '_> for PlaylistSearch {
     type Request = PlaylistSearchRequest;
     type Response = ();
     const COMMAND: &'static str = "playlistsearch";

src/commands/queue/plchanges.rs

@@ -15,7 +15,7 @@ pub struct PlChangesRequest {
     pub window: Option<WindowRange>,
 }
 
-impl Command for PlChanges {
+impl Command<'_, '_> for PlChanges {
     type Request = PlChangesRequest;
     type Response = ();
     const COMMAND: &'static str = "plchanges";

src/commands/queue/plchangesposid.rs

@@ -15,7 +15,7 @@ pub struct PlChangesPosIdRequest {
     pub window: Option<WindowRange>,
 }
 
-impl Command for PlChangesPosId {
+impl Command<'_, '_> for PlChangesPosId {
     type Request = PlChangesPosIdRequest;
     type Response = ();
     const COMMAND: &'static str = "plchangesposid";