public void ImprovingDefaultMessagesWithAKnownExpectation()
{
var labeled = Label(AB, "'A' followed by 'B'");
//When p succeeds after consuming input, Label(p) is the same as p.
AB.Parses(Tokenize("AB")).WithNoMessage().WithValue("AB");
labeled.Parses(Tokenize("AB")).WithNoMessage().WithValue("AB");
//When p fails after consuming input, Label(p) is the same as p.
AB.FailsToParse(Tokenize("A!")).LeavingUnparsedTokens("!").WithMessage("(1, 2): B expected");
labeled.FailsToParse(Tokenize("A!")).LeavingUnparsedTokens("!").WithMessage("(1, 2): B expected");
//When p succeeds but does not consume input, Label(p) still succeeds but the potential failure is included.
var succeedWithoutConsuming = new MonadicUnitParser <Token>(new Token(null, new Position(0, 0), "$"));
succeedWithoutConsuming
.PartiallyParses(Tokenize("!"))
.LeavingUnparsedTokens("!")
.WithNoMessage()
.WithValue(Lexeme("$"));
Label(succeedWithoutConsuming, "nothing")
.PartiallyParses(Tokenize("!"))
.LeavingUnparsedTokens("!")
.WithMessage("(1, 1): nothing expected")
.WithValue(Lexeme("$"));
//When p fails but does not consume input, Label(p) fails with the given expectation.
AB.FailsToParse(Tokenize("!")).LeavingUnparsedTokens("!").WithMessage("(1, 1): A expected");
labeled.FailsToParse(Tokenize("!")).LeavingUnparsedTokens("!").WithMessage("(1, 1): 'A' followed by 'B' expected");
}
public void CanBuildParserWhichSimulatesSuccessfulParsingOfGivenValueWithoutConsumingInput()
{
var parser = new MonadicUnitParser <int>(1);
parser.PartiallyParses(Tokenize("input")).LeavingUnparsedTokens("i", "n", "p", "u", "t").WithValue(1);
}
