public static RuleCallbackPair Token(Action <Token> onMatched)
{
var rule = new SingleTokenParser(t => RuleResult.Complete(t));
return(new RuleCallbackPair(() => rule, Wrapper));
void Wrapper(object node)
{
onMatched((Token)node);
}
}
public static RuleCallbackPair Token(TokenType type, string content)
{
var rule = new SingleTokenParser(t =>
{
if (t.Type == type && t.Content == content)
{
return(RuleResult.Complete(t));
}
string errMsg = $"Expected the {type} \"{content}\", but got the {t.Type} \"{t.Content}\"";
return(RuleResult.Failed(t.Position, errMsg));
});
return(new RuleCallbackPair(() => rule, BlankCallback));
void BlankCallback(object node)
{
}
}
public RuleResult FeedToken(Token t)
{
if (_isFinished)
{
throw new Exception("Tried to feed a token to an already-finished ThenChainParser.");
}
var currentCallabck = _ruleSequence[_currentRuleIndex].onMatched;
// HACK: Create the first rule, if it hasn't been already.
if (_currentRule == null)
{
_currentRule = _ruleSequence[_currentRuleIndex].ruleFactory();
}
// Feed the token to the current rule
var result = _currentRule.FeedToken(t);
// If it failed, cascade that failure upwards
if (result.status == RuleStatus.Failed)
{
return(result);
}
// If it succeeded, invoke the callback and move to the next rule
if (result.status == RuleStatus.Complete)
{
currentCallabck(result.node);
_currentRuleIndex++;
// If the last rule just succeeded, the whole chain is complete.
if (_currentRuleIndex >= _ruleSequence.Count)
{
_isFinished = true;
return(RuleResult.Complete(_node));
}
_currentRule = _ruleSequence[_currentRuleIndex].ruleFactory();
}
return(RuleResult.GoodSoFar());
}
public static RuleCallbackPair Token(TokenType type, Action <string> onMatched)
{
var rule = new SingleTokenParser(t =>
{
if (t.Type == type)
{
return(RuleResult.Complete(t));
}
string errMsg = $"Expected a {type}, but got the {t.Type} \"{t.Content}\"";
return(RuleResult.Failed(t.Position, errMsg));
});
return(new RuleCallbackPair(() => rule, Wrapper));
void Wrapper(object node)
{
var token = (Token)node;
onMatched(token.Content);
}
}
