private IEnumerable <RuleResult> ImplCoroutine(CurrentTokenCallback t)
{
while (_shouldKeepLooping(t()))
{
_rules.Reset();
// Keep feeding tokens until one of the rules completes, or
// until there's an error.
RuleResult result = RuleResult.GoodSoFar();
while (result.status == RuleStatus.GoodSoFar)
{
result = _rules.FeedToken(t());
if (result.status == RuleStatus.GoodSoFar)
{
yield return(result);
}
}
switch (result.status)
{
case RuleStatus.Complete:
yield return(RuleResult.GoodSoFar());
continue;
case RuleStatus.Failed:
IsFinished = true;
yield return(result);
yield break;
default:
IsFinished = true;
yield return(RuleResult.Failed(t().Position, "Unexpected rule result " + result.status));
yield break;
}
}
IsFinished = true;
yield return(RuleResult.Complete(_node));
}
private static RuleResult SpecificToken(
Token t,
TokenType type,
string content,
object node = null
)
{
if (t.Type != type || t.Content != content)
{
string msg = $@"Expected the {type} ""{content}"", but got the {t.Type} ""{t.Content}"" instead.";
return(RuleResult.Failed(t.Position, msg));
}
// If a node was provided, return a Completed result instead of GoodSoFar
if (node != null)
{
return(RuleResult.Complete(node));
}
return(RuleResult.GoodSoFar());
}
