private bool Rest(Parser <TToken, T> parser, ref ParseState <TToken> state, ref ExpectedCollector <TToken> expecteds, List <T> ts)
{
var lastStartingLoc = state.Location;
var childExpecteds = new ExpectedCollector <TToken>();
var success = parser.TryParse(ref state, ref childExpecteds, out var result);
while (success)
{
var endingLoc = state.Location;
childExpecteds.Clear();
if (endingLoc <= lastStartingLoc)
{
childExpecteds.Dispose();
throw new InvalidOperationException("Many() used with a parser which consumed no input");
}
ts.Add(result);
lastStartingLoc = endingLoc;
success = parser.TryParse(ref state, ref childExpecteds, out result);
}
var lastParserConsumedInput = state.Location > lastStartingLoc;
expecteds.AddIf(ref childExpecteds, lastParserConsumedInput);
childExpecteds.Dispose();
// we fail if the most recent parser failed after consuming input.
// it sets state.Error for us
return(!lastParserConsumedInput);
}
// see comment about expecteds in ParseState.Error.cs
internal sealed override bool TryParse(ref ParseState <TToken> state, ref ExpectedCollector <TToken> expecteds, out T result)
{
var firstTime = true;
var err = new InternalError <TToken>(
Maybe.Nothing <TToken>(),
false,
state.Location,
"OneOf had no arguments"
);
var childExpecteds = new ExpectedCollector <TToken>(); // the expecteds for all loop iterations
var grandchildExpecteds = new ExpectedCollector <TToken>(); // the expecteds for the current loop iteration
foreach (var p in _parsers)
{
var thisStartLoc = state.Location;
var success = p.TryParse(ref state, ref grandchildExpecteds, out result);
if (success)
{
// throw out all expecteds
grandchildExpecteds.Dispose();
childExpecteds.Dispose();
return(true);
}
// we'll usually return the error from the first parser that didn't backtrack,
// even if other parsers had a longer match.
// There is some room for improvement here.
if (state.Location > thisStartLoc)
{
// throw out all expecteds except this one
expecteds.Add(ref grandchildExpecteds);
childExpecteds.Dispose();
grandchildExpecteds.Dispose();
result = default;
return(false);
}
childExpecteds.Add(ref grandchildExpecteds);
grandchildExpecteds.Clear();
// choose the longest match, preferring the left-most error in a tie,
// except the first time (avoid returning "OneOf had no arguments").
if (firstTime || state.Error.ErrorLocation > err.ErrorLocation)
{
err = state.Error;
}
firstTime = false;
}
state.Error = err;
expecteds.Add(ref childExpecteds);
childExpecteds.Dispose();
grandchildExpecteds.Dispose();
result = default;
return(false);
}
internal sealed override bool TryParse(ref ParseState <TToken> state, ref ExpectedCollector <TToken> expecteds, out U result)
{
var success1 = _parser.TryParse(ref state, ref expecteds, out var result1);
if (!success1)
{
// state.Error set by _parser
result = default;
return(false);
}
var chainer = _factory();
chainer.Apply(result1);
var lastStartLoc = state.Location;
var childExpecteds = new ExpectedCollector <TToken>();
var success = _parser.TryParse(ref state, ref childExpecteds, out var childResult);
while (success)
{
var endLoc = state.Location;
childExpecteds.Clear();
if (endLoc <= lastStartLoc)
{
childExpecteds.Dispose();
chainer.OnError();
throw new InvalidOperationException("Many() used with a parser which consumed no input");
}
chainer.Apply(childResult);
lastStartLoc = endLoc;
success = _parser.TryParse(ref state, ref childExpecteds, out childResult);
}
var lastParserConsumedInput = state.Location > lastStartLoc;
expecteds.AddIf(ref childExpecteds, lastParserConsumedInput);
childExpecteds.Dispose();
if (lastParserConsumedInput) // the most recent parser failed after consuming input
{
// state.Error set by _parser
chainer.OnError();
result = default;
return(false);
}
result = chainer.GetResult();
return(true);
}
internal sealed override bool TryParse(ref ParseState <TToken> state, ref ExpectedCollector <TToken> expecteds, out T result)
{
var childExpecteds = new ExpectedCollector <TToken>();
var success = _parser.TryParse(ref state, ref childExpecteds, out result);
expecteds.AddIf(ref childExpecteds, success);
childExpecteds.Dispose();
if (!success)
{
return(false);
}
if (!_predicate(result))
{
state.Error = new InternalError <TToken>(
Maybe.Nothing <TToken>(),
false,
state.Location,
_message(result)
);
expecteds.Add(_expected);
result = default;
return(false);
}
return(true);
}
internal sealed override bool TryParse(ref ParseState <TToken> state, ref ExpectedCollector <TToken> expecteds, out Unit result)
{
var startingLocation = state.Location;
var token = state.HasCurrent ? Maybe.Just(state.Current) : Maybe.Nothing <TToken>();
state.PushBookmark(); // make sure we don't throw out the buffer, we may need it to compute a SourcePos
var childExpecteds = new ExpectedCollector <TToken>(true);
var success = _parser.TryParse(ref state, ref childExpecteds, out var result1);
childExpecteds.Dispose();
state.PopBookmark();
if (success)
{
state.Error = new InternalError <TToken>(
token,
false,
startingLocation,
null
);
result = default;
return(false);
}
result = Unit.Value;
return(true);
}
// see comment about expecteds in ParseState.Error.cs
internal sealed override bool TryParse(ref ParseState <TToken> state, ref ExpectedCollector <TToken> expecteds, out T result)
{
var childExpecteds = new ExpectedCollector <TToken>();
var success = _parser.TryParse(ref state, ref childExpecteds, out result);
if (success)
{
childExpecteds.Dispose();
return(true);
}
var recoverParser = _errorHandler(state.BuildError(ref childExpecteds));
childExpecteds.Dispose();
return(recoverParser.TryParse(ref state, ref expecteds, out result));
}
internal sealed override bool TryParse(ref ParseState <TToken> state, ref ExpectedCollector <TToken> expecteds, out T result)
{
var childExpecteds = new ExpectedCollector <TToken>(true);
var success = _parser.TryParse(ref state, ref childExpecteds, out result);
childExpecteds.Dispose();
if (!success)
{
expecteds.Add(_expected);
}
return(success);
}
private static Result <TToken, T> DoParse <TToken, T>(Parser <TToken, T> parser, ref ParseState <TToken> state)
{
var startingLoc = state.Location;
var expecteds = new ExpectedCollector <TToken>();
var success = parser.TryParse(ref state, ref expecteds, out var result);
var result1 = success
? new Result <TToken, T>(state.Location > startingLoc, result)
: new Result <TToken, T>(state.Location > startingLoc, state.BuildError(ref expecteds));
expecteds.Dispose();
state.Dispose(); // ensure we return the state's buffers to the buffer pool
return(result1);
}
// see comment about expecteds in ParseState.Error.cs
internal sealed override bool TryParse(ref ParseState <TToken> state, ref ExpectedCollector <TToken> expecteds, out IEnumerable <T>?result)
{
var ts = _keepResults ? new List <T>() : null;
var firstItemStartLoc = state.Location;
var firstItemSuccess = _parser.TryParse(ref state, ref expecteds, out var result1);
if (!firstItemSuccess)
{
// state.Error set by _parser
result = null;
return(false);
}
if (state.Location <= firstItemStartLoc)
{
throw new InvalidOperationException("Until() used with a parser which consumed no input");
}
ts?.Add(result1);
var terminatorExpecteds = new ExpectedCollector <TToken>();
var itemExpecteds = new ExpectedCollector <TToken>();
while (true)
{
var terminatorStartLoc = state.Location;
var terminatorSuccess = _terminator.TryParse(ref state, ref terminatorExpecteds, out var terminatorResult);
if (terminatorSuccess)
{
terminatorExpecteds.Dispose();
itemExpecteds.Dispose();
result = ts;
return(true);
}
if (state.Location > terminatorStartLoc)
{
// state.Error set by _terminator
expecteds.Add(ref terminatorExpecteds);
terminatorExpecteds.Dispose();
itemExpecteds.Dispose();
result = null;
return(false);
}
var itemStartLoc = state.Location;
var itemSuccess = _parser.TryParse(ref state, ref itemExpecteds, out var itemResult);
var itemConsumedInput = state.Location > itemStartLoc;
if (!itemSuccess)
{
if (!itemConsumedInput)
{
// get the expected from both _terminator and _parser
expecteds.Add(ref terminatorExpecteds);
expecteds.Add(ref itemExpecteds);
}
else
{
// throw out the _terminator expecteds and keep only _parser
expecteds.Add(ref itemExpecteds);
}
terminatorExpecteds.Dispose();
itemExpecteds.Dispose();
result = null;
return(false);
}
// throw out both sets of expecteds
terminatorExpecteds.Clear();
itemExpecteds.Clear();
if (!itemConsumedInput)
{
throw new InvalidOperationException("Until() used with a parser which consumed no input");
}
ts?.Add(itemResult);
}
}
internal sealed override bool TryParse(ref ParseState <TToken> state, ref ExpectedCollector <TToken> expecteds, out IEnumerable <T> result)
{
var success = _parser.TryParse(ref state, ref expecteds, out var result1);
if (!success)
{
// state.Error set by _parser
result = null;
return(false);
}
var ts = new List <T> {
result1
};
var childExpecteds = new ExpectedCollector <TToken>();
while (true)
{
var sepStartLoc = state.Location;
var sepSuccess = _separator.TryParse(ref state, ref childExpecteds, out var _);
var sepConsumedInput = state.Location > sepStartLoc;
expecteds.AddIf(ref childExpecteds, !sepSuccess && sepConsumedInput);
childExpecteds.Clear();
if (!sepSuccess)
{
childExpecteds.Dispose();
if (sepConsumedInput)
{
// state.Error set by _separator
result = null;
return(false);
}
result = ts;
return(true);
}
var itemStartLoc = state.Location;
var itemSuccess = _parser.TryParse(ref state, ref childExpecteds, out var itemResult);
var itemConsumedInput = state.Location > itemStartLoc;
expecteds.AddIf(ref childExpecteds, !itemSuccess && itemConsumedInput);
childExpecteds.Clear();
if (!itemSuccess)
{
childExpecteds.Dispose();
if (itemConsumedInput)
{
// state.Error set by _parser
result = null;
return(false);
}
result = ts;
return(true);
}
ts.Add(itemResult);
}
}
