mpd/src/cmdline/OptionParser.hxx
2023-03-06 14:59:48 +01:00

63 lines
1.3 KiB
C++

// SPDX-License-Identifier: GPL-2.0-or-later
// Copyright The Music Player Daemon Project
#ifndef MPD_UTIL_OPTIONPARSER_HXX
#define MPD_UTIL_OPTIONPARSER_HXX
#include "OptionDef.hxx"
#include <span>
/**
* Command line option parser.
*/
class OptionParser
{
std::span<const OptionDef> options;
std::span<const char *const> args;
const char **const remaining_head, **remaining_tail;
public:
/**
* Constructs #OptionParser.
*/
OptionParser(std::span<const OptionDef> _options,
int _argc, char **_argv) noexcept
:options(_options), args(_argv + 1, _argc - 1),
remaining_head(const_cast<const char **>(_argv + 1)),
remaining_tail(remaining_head) {}
struct Result {
int index;
const char *value;
constexpr operator bool() const noexcept {
return index >= 0;
}
};
/**
* Parses current command line entry.
* Regardless of result, advances current position to the next
* command line entry.
*
* Throws on error.
*/
Result Next();
/**
* Returns the remaining non-option arguments.
*/
std::span<const char *const> GetRemaining() const noexcept {
return {remaining_head, remaining_tail};
}
private:
const char *CheckShiftValue(const char *s, const OptionDef &option);
Result IdentifyOption(const char *s);
};
#endif