internal Result(bool consumedInput, T value)
{
Success = true;
ConsumedInput = consumedInput;
_value = value;
_error = default(ParseError <TToken>);
}
internal Result(bool consumedInput, ParseError <TToken> error)
{
Success = false;
ConsumedInput = consumedInput;
_value = default(T);
_error = error;
}
internal sealed override InternalResult <T> Parse(ref ParseState <TToken> state)
{
var firstTime = true;
var err = new ParseError <TToken>(
Maybe.Nothing <TToken>(),
false,
Expected,
state.SourcePos,
"OneOf had no arguments"
);
InternalResult <T> failureResult = InternalResult.Failure <T>(false);
foreach (var p in _parsers)
{
var thisResult = p.Parse(ref state);
// 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 (thisResult.Success || thisResult.ConsumedInput)
{
return(thisResult);
}
// 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.ErrorPos > err.ErrorPos)
{
failureResult = thisResult;
err = state.Error;
}
firstTime = false;
}
state.Error = err.WithExpected(Expected);
return(failureResult);
}
public ParseState(Func <TToken, SourcePos, SourcePos> posCalculator, ITokenStream <TToken> stream)
{
_posCalculator = posCalculator;
_bookmarks = new Stack <Bookmark>();
_stream = stream;
_consumedCount = 0;
_hasCurrent = false;
SourcePos = new SourcePos(1, 1);
Error = default;
}
/// <inheritdoc/> public bool Equals(ParseError <TToken> other) => this.Unexpected.Equals(other.Unexpected) && this.EOF == other.EOF && (this.Expected == null && other.Expected == null || this.Expected.SequenceEqual(other.Expected)) && this.ErrorPos.Equals(other.ErrorPos) && object.Equals(this.Message, other.Message);
internal static Result <TToken, T> Failure <TToken, T>(
ParseError <TToken> error,
bool consumedInput
) => new Result <TToken, T>(error, consumedInput);
public bool Equals(ParseError <TToken> other) => this.Unexpected.Equals(other.Expected) && this.EOF == other.EOF && object.Equals(this.Expected, other.Expected) && this.ErrorPos.Equals(other.ErrorPos) && object.Equals(this.Message, other.Message);
