public IEither <T, ParseError> Parse(IInputReader input)
{
Position position = input.GetPosition();
var result = this.parserA.Parse(input);
if (result.IsSuccess || input.GetPosition() != position)
{
return(result);
}
return(this.parserB.Parse(input));
}
public void Try_Error_ReturnsErrorAndResetsPosition()
{
var parser = Parse.Try(from x in Chars.Any()
from y in Chars.Any()
from f in Parse.Fail <char>("test")
select x);
IInputReader input = InputReader.Create("abc");
Position expectedPosition = input.GetPosition();
var result = parser.Parse(input);
ParseAssert.IsError(result);
Assert.AreEqual(expectedPosition, input.GetPosition());
}
public void Seek_UpdatesPosition()
{
IInputReader stream = CreateInputStream("abc");
Position position = stream.GetPosition();
stream.Read();
stream.Read();
stream.Seek(position);
Position newPosition = stream.GetPosition();
Assert.AreEqual(position, newPosition);
char result = (char)stream.Read();
Assert.AreEqual('a', result);
}
public void GetPosition_NothingRead()
{
IInputReader stream = CreateInputStream("");
Position position = stream.GetPosition();
Assert.AreEqual(1, position.Line, "Line");
Assert.AreEqual(1, position.Column, "Column");
}
public void GetPosition_Read_DoesNotUpdateReturnedPosition()
{
IInputReader stream = CreateInputStream("abc");
Position position = stream.GetPosition();
stream.Read();
Assert.AreEqual(1, position.Line, "Line");
Assert.AreEqual(1, position.Column, "Column");
}
public void GetPosition_ReadChar()
{
IInputReader stream = CreateInputStream("abc\nxyz");
stream.Read();
Position position = stream.GetPosition();
Assert.AreEqual(1, position.Line, "Line");
Assert.AreEqual(2, position.Column, "Column");
}
public IParseResult <Unit> TryParse(IInputReader inp)
{
var pos = inp.GetPosition();
var result = _parser.TryParse(inp);
if (result.IsSuccess())
{
inp.Seek(pos);
return(Parse.Error <Unit>($"Expect {_parser.Name}, but got '{result.Result}'", inp));
}
return(Parse.Success(Unit.Instance));
}
public IParseResult <T> TryParse(IInputReader inp)
{
var pos = inp.GetPosition();
var parsed = _parser.TryParse(inp);
if (!parsed.IsSuccess())
{
return(Parse.Error <T>(parsed.Error));
}
inp.Seek(pos);
return(Parse.Success <T>());
}
public IEither <TResult, ParseError> Parse(IInputReader input)
{
TAccum acc = this.seed();
IEither <T, ParseError> result = null;
Position position = input.GetPosition();
while ((result = this.parser.Parse(input)).IsSuccess)
{
acc = this.func(acc, result.FromSuccess());
position = input.GetPosition();
}
if (input.GetPosition() == position)
{
return(ParseResult.Success(this.resultSelector(acc)));
}
else
{
return(ParseResult.Error <TResult>(result.FromError()));
}
}
public IEither <T, ParseError> Parse(IInputReader input)
{
Position position = input.GetPosition();
var result = this.parser.Parse(input);
if (result.IsError)
{
input.Seek(position);
}
return(result);
}
public IParseResult <TResult> TryParse(IInputReader inp)
{
TAccum acc = _seed();
do
{
var pos = inp.GetPosition();
var parsed = _parser.TryParse(inp);
if (!parsed.IsSuccess())
{
inp.Seek(pos);
break;
}
acc = _accFunc(acc, parsed.Result);
} while (!inp.Eof());
return(Parse.Success(_resultSelector(acc)));
}
public IParseResult <T1> TryParse(IInputReader inp)
{
var parsed1 = _p1.TryParse(inp);
if (!parsed1.IsSuccess())
{
return(parsed1);
}
var pos = inp.GetPosition();
var parsed2 = _p2.TryParse(inp);
if (!parsed2.IsSuccess())
{
return(Parse.Error <T1>(parsed1.Error));
}
inp.Seek(pos);
return(parsed1);
}
public IParseResult <IEnumerable <T> > TryParse(IInputReader inp)
{
var acc = new T[_parsers.Length];
var idx = 0;
var pos = inp.GetPosition();
foreach (var parser in _parsers)
{
var parsed = parser.TryParse(inp);
if (!parsed.IsSuccess())
{
inp.Seek(pos);
return(Parse.Error <IEnumerable <T> >(parsed.Error));
}
acc[idx] = parsed.Result;
idx++;
}
return(Parse.Success <IEnumerable <T> >(acc));
}
public IParseResult <T> TryParse(IInputReader inp)
{
var pos1 = inp.GetPosition();
var parsed1 = _parserA.TryParse(inp);
if (parsed1.IsSuccess())
{
return(parsed1);
}
inp.Seek(pos1);
var parsed2 = _parserB.TryParse(inp);
if (parsed2.IsSuccess())
{
return(parsed2);
}
var ch = inp.Substr(20);
return(Parse.Error <T>($"Expect {Name}, but got '{ch}'", inp));
}
public static IEither <T, ParseError> UnexpectedValue <T>(IInputReader input, object value)
{
return(Error <T>(new ParseError(input.GetPosition(), "Unexpected \"" + value.ToString() + "\"")));
}
public static IEither <T, ParseError> Error <T>(IInputReader input, Func <string> messageFn, ParseError innerError)
{
return(Error <T>(new ParseError(input.GetPosition(), messageFn, innerError)));
}
public static IEither <T, ParseError> Error <T>(IInputReader input, string message)
{
return(Error <T>(new ParseError(input.GetPosition(), message)));
}