public static Parser <List <T>, TToken> Many <T, TToken>(this Parser <T, TToken> parser, int least = 0, int most = int.MaxValue)
{
if (parser is null)
{
throw new ArgumentNullException(nameof(parser));
}
return(input =>
{
List <T> elements = new List <T>();
LexemeString <TToken> remainder = input;
for (int i = 0; i <= most; i++)
{
var result = parser(remainder);
if (!result.IsSuccessful)
{
if (i < least)
{
return ParserResult.Error <T, List <T>, TToken>(result);
//return ParserResult.Error<List<T>, TToken>("Too few elements. Expected at least " + least, remainder);
}
return ParserResult.Success(elements, remainder);
}
elements.Add(result.Result);
remainder = result.RemainingLexemes;
}
return ParserResult.Success(elements, remainder);
});
}
public ParserError(string errorMessage, LexemeString <TToken> remainingLexemes)
{
ErrorMessage = errorMessage;
RemainingLexemes = remainingLexemes;
}
private static IParserResult <T, Token> ParseEoF <T>(Parser <T, Token> parser, LexemeString <Token> lexemes)
{
var result = parser(lexemes);
if (!result.IsSuccessful)
{
return(result);
}
if (result.RemainingLexemes.Length > 1)
{
var remaining = result.RemainingLexemes[0] + (result.RemainingLexemes.Length > 1 ? " " + result.RemainingLexemes[1] : "");
return(ParserResult.Error <T, Token>("Error matching " + remaining + " found " + result.Result, result.RemainingLexemes));
}
return(result);
}
public static IParserResult <T, TToken> Success <T, TToken>(T result, LexemeString <TToken> remainingLexemes) => new ParserSuccess <T, TToken>(result, remainingLexemes);
public static IParserResult <T, TToken> Error <T, TToken>(string errorMessage, LexemeString <TToken> remainingLexemes) => new ParserError <T, TToken>(errorMessage, remainingLexemes);
public ParserSuccess(T result, LexemeString <TToken> remainingLexemeString)
{
Result = result;
RemainingLexemes = remainingLexemeString;
}