Implement rational numbers in WebAssembly using num-bigint

2021-05-30 23:00:28 +10:00 · 2021-05-30 23:00:28 +10:00 · 2428fcb4ed
parent 2793088e12
commit 2428fcb4ed
7 changed files with 436 additions and 66 deletions
--- a/Cargo.lock
+++ b/Cargo.lock
@ -239,6 +239,39 @@ dependencies = [
 "autocfg",
 ]

+[[package]]
+name = "num-bigint"
+version = "0.4.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "4e0d047c1062aa51e256408c560894e5251f08925980e53cf1aa5bd00eec6512"
+dependencies = [
+ "autocfg",
+ "num-integer",
+ "num-traits",
+]
+
+[[package]]
+name = "num-integer"
+version = "0.1.44"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d2cc698a63b549a70bc047073d2949cce27cd1c7b0a4a862d08a8031bc2801db"
+dependencies = [
+ "autocfg",
+ "num-traits",
+]
+
+[[package]]
+name = "num-rational"
+version = "0.4.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d41702bd167c2df5520b384281bc111a4b5efcf7fbc4c9c222c815b07e0a6a6a"
+dependencies = [
+ "autocfg",
+ "num-bigint",
+ "num-integer",
+ "num-traits",
+]
+
 [[package]]
 name = "num-traits"
 version = "0.2.14"
@ -257,7 +290,10 @@ dependencies = [
 "csv",
 "flate2",
 "git-version",
+ "num-bigint",
+ "num-rational",
 "num-traits",
+ "paste",
 "rug",
 "wasm-bindgen",
 ]
@ -268,6 +304,12 @@ version = "3.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "6acbef58a60fe69ab50510a55bc8cdd4d6cf2283d27ad338f54cb52747a9cf2d"

+[[package]]
+name = "paste"
+version = "1.0.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "acbf547ad0c65e31259204bd90935776d1c693cec2f4ff7abb7a1bbbd40dfe58"
+
 [[package]]
 name = "proc-macro-error"
 version = "1.0.4"
--- a/Cargo.toml
+++ b/Cargo.toml
@ -13,7 +13,11 @@ num-traits = "0.2"
 wasm-bindgen = "0.2.74"

 # Only for WebAssembly - include here for syntax highlighting
+#[target.'cfg(target_arch = "wasm32")'.dependencies]
 console_error_panic_hook = "0.1.6"
+num-bigint = "0.4.0"
+num-rational = "0.4.0"
+paste = "1.0.5"

 [target.'cfg(not(target_arch = "wasm32"))'.dependencies]
 csv = "1.1.6"
--- a/pkg/test.html
+++ b/pkg/test.html
@ -23,24 +23,24 @@
 				document.getElementById('output').append("\n");
 			};
 			
-			var { CountStateFloat64, STVOptions, count_init_float64, count_one_stage_float64, election_from_blt_float64, make_and_print_result_float64 } = wasm_bindgen;
+			var wasm = wasm_bindgen;
 			async function run() {
 				await wasm_bindgen("opentally_bg.wasm");
 				
-				let stv_opts = STVOptions.new(2, "one_round");
+				let stv_opts = wasm.STVOptions.new(2, "one_round");
 				
-				let election = election_from_blt_float64(election_data);
-				let state = CountStateFloat64.new(election);
+				let election = wasm.election_from_blt_Rational(election_data);
+				let state = wasm.CountStateRational.new(election);
 				
-				count_init_float64(state, stv_opts);
-				make_and_print_result_float64(1, state);
+				wasm.count_init_Rational(state, stv_opts);
+				wasm.make_and_print_result_Rational(1, state);
 				
 				for (let stage_num = 2;; stage_num++) {
-					let is_done = count_one_stage_float64(state, stv_opts);
+					let is_done = wasm.count_one_stage_Rational(state, stv_opts);
 					if (is_done) {
 						break;
 					}
-					make_and_print_result_float64(stage_num, state);
+					wasm.make_and_print_result_Rational(stage_num, state);
 				}
 			}
 			run();
--- a/src/numbers/mod.rs
+++ b/src/numbers/mod.rs
@ -18,7 +18,10 @@
 mod native;

 #[cfg(not(target_arch = "wasm32"))]
-mod rational;
+mod rational_rug;
+
+//#[cfg(target_arch = "wasm32")]
+mod rational_num;

 use num_traits::{NumAssignRef, NumRef};

@ -49,4 +52,7 @@ pub trait Number: NumRef + NumAssignRef + ops::Neg<Output=Self> + Ord + Assign +
 pub use self::native::NativeFloat64;

 #[cfg(not(target_arch = "wasm32"))]
-pub use self::rational::Rational;
+pub use self::rational_rug::Rational;
+
+#[cfg(target_arch = "wasm32")]
+pub use self::rational_num::Rational;
--- a/src/numbers/rational_num.rs
+++ b/src/numbers/rational_num.rs
@ -0,0 +1,303 @@
+/*  OpenTally: Open-source election vote counting
+ *  Copyright © 2021 Lee Yingtong Li (RunasSudo)
+ *
+ *  This program is free software: you can redistribute it and/or modify
+ *  it under the terms of the GNU Affero General Public License as published by
+ *  the Free Software Foundation, either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU Affero General Public License for more details.
+ *
+ *  You should have received a copy of the GNU Affero General Public License
+ *  along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+use super::{Assign, Number};
+
+use num_bigint::{BigInt, ParseBigIntError};
+use num_rational::BigRational; // TODO: Can we do Ratio<IBig> and combine with ibig?
+use num_traits::{Num, One, Signed, Zero};
+
+use std::cmp::{Ord, Ordering, PartialEq, PartialOrd};
+use std::fmt;
+use std::ops;
+
+pub struct Rational(BigRational);
+
+impl Number for Rational {
+	fn new() -> Self { Self(BigRational::zero()) }
+	
+	fn from(n: usize) -> Self { Self(BigRational::from_integer(BigInt::from(n))) }
+	
+	fn floor_mut(&mut self, dps: usize) {
+		if dps == 0 {
+			self.0 = self.0.floor();
+		} else {
+			let factor = BigRational::from_integer(BigInt::from(10)).pow(dps as i32);
+			self.0 *= &factor;
+			self.0 = self.0.floor();
+			self.0 /= factor;
+		}
+	}
+}
+
+impl Num for Rational {
+	//type FromStrRadixErr = ParseRatioError;
+	type FromStrRadixErr = ParseBigIntError;
+	
+	fn from_str_radix(str: &str, radix: u32) -> Result<Self, Self::FromStrRadixErr> {
+		//match BigRational::from_str_radix(str, radix) {
+		match BigInt::from_str_radix(str, radix) {
+			Ok(value) => Ok(Self(BigRational::from_integer(value))),
+			Err(err) => Err(err)
+		}
+	}
+}
+
+impl Assign for Rational {
+	fn assign(&mut self, src: Self) { self.0 = src.0 }
+}
+
+impl Assign<&Rational> for Rational {
+	fn assign(&mut self, src: &Rational) { self.0 = src.0.clone() }
+}
+
+impl Clone for Rational {
+	fn clone(&self) -> Self { Self(self.0.clone()) }
+}
+
+impl fmt::Display for Rational {
+	fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+		if let Some(precision) = f.precision() {
+			if precision == 0 {
+				let result = self.0.round().to_integer().to_string();
+				return f.write_str(&result);
+			} else {
+				let base = BigInt::from(10).pow(precision as u32);
+				let mut result = (&self.0 * base).abs().round().to_integer().to_string();
+				
+				let should_add_minus = (self.0 < BigRational::zero()) && result != "0";
+				
+				// Add leading 0s
+				result = format!("{0:0>1$}", result, precision + 1);
+				
+				// Add the decimal point
+				result.insert(result.len() - precision, '.');
+				
+				// Add the sign
+				if should_add_minus {
+					result.insert(0, '-');
+				}
+				
+				return f.write_str(&result);
+			}
+		} else {
+			return self.0.fmt(f);
+		}
+	}
+}
+
+impl One for Rational {
+	fn one() -> Self { Self(BigRational::one()) }
+}
+
+impl Zero for Rational {
+	fn zero() -> Self { Self::new() }
+	fn is_zero(&self) -> bool { self.0.is_zero() }
+}
+
+impl Eq for Rational {}
+impl PartialEq for Rational {
+	fn eq(&self, other: &Self) -> bool { self.0 == other.0 }
+}
+
+impl Ord for Rational {
+	fn cmp(&self, other: &Self) -> Ordering { self.0.partial_cmp(&other.0).unwrap() }
+}
+
+impl PartialOrd for Rational {
+	fn partial_cmp(&self, other: &Self) -> Option<Ordering> { self.0.partial_cmp(&other.0) }
+}
+
+impl ops::Neg for Rational {
+	type Output = Rational;
+	fn neg(self) -> Self::Output { Self(-self.0) }
+}
+
+impl ops::Add for Rational {
+	type Output = Rational;
+	fn add(self, _rhs: Self) -> Self::Output {
+		todo!()
+	}
+}
+
+impl ops::Sub for Rational {
+	type Output = Rational;
+	fn sub(self, _rhs: Self) -> Self::Output {
+		todo!()
+	}
+}
+
+impl ops::Mul for Rational {
+	type Output = Rational;
+	fn mul(self, _rhs: Self) -> Self::Output {
+		todo!()
+	}
+}
+
+impl ops::Div for Rational {
+	type Output = Rational;
+	fn div(self, _rhs: Self) -> Self::Output {
+		todo!()
+	}
+}
+
+impl ops::Rem for Rational {
+	type Output = Rational;
+	
+	fn rem(self, _rhs: Self) -> Self::Output {
+		todo!()
+	}
+}
+
+impl ops::Add<&Rational> for Rational {
+	type Output = Rational;
+	fn add(self, rhs: &Rational) -> Self::Output { Self(self.0 + &rhs.0) }
+}
+
+impl ops::Sub<&Rational> for Rational {
+	type Output = Rational;
+	fn sub(self, _rhs: &Rational) -> Self::Output {
+		todo!()
+	}
+}
+
+impl ops::Mul<&Rational> for Rational {
+	type Output = Rational;
+	fn mul(self, rhs: &Rational) -> Self::Output { Rational(self.0 * &rhs.0) }
+}
+
+impl ops::Div<&Rational> for Rational {
+	type Output = Rational;
+	fn div(self, rhs: &Rational) -> Self::Output { Rational(self.0 / &rhs.0) }
+}
+
+impl ops::Rem<&Rational> for Rational {
+	type Output = Rational;
+	fn rem(self, _rhs: &Rational) -> Self::Output {
+		todo!()
+	}
+}
+
+impl ops::AddAssign for Rational {
+	fn add_assign(&mut self, rhs: Self) { self.0 += rhs.0 }
+}
+
+impl ops::SubAssign for Rational {
+	fn sub_assign(&mut self, rhs: Self) { self.0 -= rhs.0 }
+}
+
+impl ops::MulAssign for Rational {
+	fn mul_assign(&mut self, _rhs: Self) {
+		todo!()
+	}
+}
+
+impl ops::DivAssign for Rational {
+	fn div_assign(&mut self, rhs: Self) {
+		self.0 /= &rhs.0;
+	}
+}
+
+impl ops::RemAssign for Rational {
+	fn rem_assign(&mut self, _rhs: Self) {
+		todo!()
+	}
+}
+
+impl ops::AddAssign<&Rational> for Rational {
+	fn add_assign(&mut self, rhs: &Rational) { self.0 += &rhs.0 }
+}
+
+impl ops::SubAssign<&Rational> for Rational {
+	fn sub_assign(&mut self, rhs: &Rational) { self.0 -= &rhs.0 }
+}
+
+impl ops::MulAssign<&Rational> for Rational {
+	fn mul_assign(&mut self, _rhs: &Rational) {
+		todo!()
+	}
+}
+
+impl ops::DivAssign<&Rational> for Rational {
+	fn div_assign(&mut self, _rhs: &Rational) {
+		todo!()
+	}
+}
+
+impl ops::RemAssign<&Rational> for Rational {
+	fn rem_assign(&mut self, _rhs: &Rational) {
+		todo!()
+	}
+}
+
+impl ops::Neg for &Rational {
+	type Output = Rational;
+	fn neg(self) -> Self::Output { Rational(-&self.0) }
+}
+
+impl ops::Add<&Rational> for &Rational {
+	type Output = Rational;
+	fn add(self, _rhs: &Rational) -> Self::Output {
+		todo!()
+	}
+}
+
+impl ops::Sub<&Rational> for &Rational {
+	type Output = Rational;
+	fn sub(self, rhs: &Rational) -> Self::Output { Rational(&self.0 - &rhs.0) }
+}
+
+impl ops::Mul<&Rational> for &Rational {
+	type Output = Rational;
+	fn mul(self, _rhs: &Rational) -> Self::Output {
+		todo!()
+	}
+}
+
+impl ops::Div<&Rational> for &Rational {
+	type Output = Rational;
+	fn div(self, rhs: &Rational) -> Self::Output { Rational(&self.0 / &rhs.0) }
+}
+
+impl ops::Rem<&Rational> for &Rational {
+	type Output = Rational;
+	fn rem(self, _rhs: &Rational) -> Self::Output {
+		todo!()
+	}
+}
+
+/*
+impl ops::Add<&&NativeFloat> for &NativeFloat {
+	
+}
+
+impl ops::Sub<&&NativeFloat> for &NativeFloat {
+	
+}
+
+impl ops::Mul<&&NativeFloat> for &NativeFloat {
+	
+}
+
+impl ops::Div<&&NativeFloat> for &NativeFloat {
+	
+}
+
+impl ops::Rem<&&NativeFloat> for &NativeFloat {
+	
+}
+*/
--- a/src/numbers/rational_rug.rs
+++ b/src/numbers/rational_rug.rs
--- a/src/stv/wasm.rs
+++ b/src/stv/wasm.rs
@ -16,7 +16,7 @@
 */

 use crate::election::{Candidate, CandidateState, CountCard, CountState, CountStateOrRef, Election, StageResult};
-use crate::numbers::{NativeFloat64, Number};
+use crate::numbers::{NativeFloat64, Number, Rational};
 use crate::stv;

 extern crate console_error_panic_hook;
@ -37,29 +37,82 @@ macro_rules! cprintln {
 	)
 }

+// Helper macros for making functions
+
+macro_rules! impl_type {
+	($type:ident) => { paste::item! {
 		// Exported functions
 		
 		#[wasm_bindgen]
-pub fn election_from_blt_float64(text: String) -> ElectionFloat64 {
+		#[allow(non_snake_case)]
+		pub fn [<election_from_blt_$type>](text: String) -> [<Election$type>] {
 			// Install panic! hook
 			console_error_panic_hook::set_once();
 			
-	let election: Election<NativeFloat64> = Election::from_blt(text.lines().map(|s| s.to_string()).into_iter());
-	return ElectionFloat64(election);
+			let election: Election<$type> = Election::from_blt(text.lines().map(|s| s.to_string()).into_iter());
+			return [<Election$type>](election);
 		}
 		
 		#[wasm_bindgen]
-pub fn count_init_float64(state: &mut CountStateFloat64, opts: &STVOptions) {
+		#[allow(non_snake_case)]
+		pub fn [<count_init_$type>](state: &mut [<CountState$type>], opts: &STVOptions) {
 			stv::count_init(&mut state.0, &opts.0);
 		}
 		
 		#[wasm_bindgen]
-pub fn count_one_stage_float64(state: &mut CountStateFloat64, opts: &STVOptions) -> bool {
+		#[allow(non_snake_case)]
+		pub fn [<count_one_stage_$type>](state: &mut [<CountState$type>], opts: &STVOptions) -> bool {
 			return stv::count_one_stage(&mut state.0, &opts.0);
 		}
 		
 		// Reporting
 		
+		#[wasm_bindgen]
+		#[allow(non_snake_case)]
+		pub fn [<make_and_print_result_$type>](stage_num: usize, state: &[<CountState$type>]) {
+			let result = StageResult {
+				kind: state.0.kind,
+				title: &state.0.title,
+				logs: state.0.logger.render(),
+				state: CountStateOrRef::from(&state.0),
+			};
+			print_stage(stage_num, &result);
+		}
+		
+		// Wrapper structs
+		// Required as we cannot specify &'static in wasm-bindgen: issue #1187
+		
+		#[wasm_bindgen]
+		pub struct [<CountState$type>](CountState<'static, $type>);
+		#[wasm_bindgen]
+		impl [<CountState$type>] {
+			pub fn new(election: &[<Election$type>]) -> Self {
+				return [<CountState$type>](CountState::new(election.as_static()));
+			}
+		}
+		
+		#[wasm_bindgen]
+		pub struct [<Election$type>](Election<$type>);
+		#[wasm_bindgen]
+		impl [<Election$type>] {
+			pub fn seats(&self) -> usize { self.0.seats }
+			
+			fn as_static(&self) -> &'static Election<$type> {
+				// Need to have this as we cannot specify &'static in wasm-bindgen: issue #1187
+				unsafe {
+					let ptr = &self.0 as *const Election<$type>;
+					&*ptr
+				}
+			}
+		}
+	}}
+}
+
+impl_type!(Rational);
+impl_type!(NativeFloat64);
+
+// Reporting
+
 fn print_candidates<'a, N: 'a + Number, I: Iterator<Item=(&'a Candidate, &'a CountCard<'a, N>)>>(candidates: I) {
 	for (candidate, count_card) in candidates {
 		if count_card.state == CandidateState::ELECTED {
@ -101,44 +154,6 @@ fn print_stage<N: Number>(stage_num: usize, result: &StageResult<N>) {
 	cprintln!("");
 }

-#[wasm_bindgen]
-pub fn make_and_print_result_float64(stage_num: usize, state: &CountStateFloat64) {
-	let result = StageResult {
-		kind: state.0.kind,
-		title: &state.0.title,
-		logs: state.0.logger.render(),
-		state: CountStateOrRef::from(&state.0),
-	};
-	print_stage(stage_num, &result);
-}
-
-// Wrapper structs
-// Required as we cannot specify &'static in wasm-bindgen: issue #1187
-
-#[wasm_bindgen]
-pub struct CountStateFloat64(CountState<'static, NativeFloat64>);
-#[wasm_bindgen]
-impl CountStateFloat64 {
-	pub fn new(election: &ElectionFloat64) -> Self {
-		return CountStateFloat64(CountState::new(election.as_static()));
-	}
-}
-
-#[wasm_bindgen]
-pub struct ElectionFloat64(Election<NativeFloat64>);
-#[wasm_bindgen]
-impl ElectionFloat64 {
-	pub fn seats(&self) -> usize { self.0.seats }
-	
-	fn as_static(&self) -> &'static Election<NativeFloat64> {
-		// Need to have this as we cannot specify &'static in wasm-bindgen: issue #1187
-		unsafe {
-			let ptr = &self.0 as *const Election<NativeFloat64>;
-			&*ptr
-		}
-	}
-}
-
 #[wasm_bindgen]
 pub struct STVOptions(stv::STVOptions<'static>);
 #[wasm_bindgen]