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

81 lines
1.6 KiB
C++

// SPDX-License-Identifier: GPL-2.0-or-later
// Copyright The Music Player Daemon Project
#include "OptionParser.hxx"
#include "OptionDef.hxx"
#include "lib/fmt/RuntimeError.hxx"
#include "util/StringCompare.hxx"
static const char *
Shift(std::span<const char *const> &s) noexcept
{
const char *value = s.front();
s = s.subspan(1);
return value;
}
inline const char *
OptionParser::CheckShiftValue(const char *s, const OptionDef &option)
{
if (!option.HasValue())
return nullptr;
if (args.empty())
throw FmtRuntimeError("Value expected after {}", s);
return Shift(args);
}
inline OptionParser::Result
OptionParser::IdentifyOption(const char *s)
{
assert(s != nullptr);
assert(*s == '-');
if (s[1] == '-') {
for (const auto &i : options) {
if (!i.HasLongOption())
continue;
const char *t = StringAfterPrefix(s + 2, i.GetLongOption());
if (t == nullptr)
continue;
const char *value;
if (*t == 0)
value = CheckShiftValue(s, i);
else if (*t == '=')
value = t + 1;
else
continue;
return {int(&i - options.data()), value};
}
} else if (s[1] != 0 && s[2] == 0) {
const char ch = s[1];
for (const auto &i : options) {
if (i.HasShortOption() && ch == i.GetShortOption()) {
const char *value = CheckShiftValue(s, i);
return {int(&i - options.data()), value};
}
}
}
throw FmtRuntimeError("Unknown option: {}", s);
}
OptionParser::Result
OptionParser::Next()
{
while (!args.empty()) {
const char *arg = Shift(args);
if (arg[0] == '-')
return IdentifyOption(arg);
*remaining_tail++ = arg;
}
return {-1, nullptr};
}