internal override IEnumerable <ParseStep> Parse(IRegexEngine outerEngine)
{
var engine = new RegexEngine.RegexEngineInternal(GetEngineInput(outerEngine));
foreach (var capture in outerEngine.GetAllDefinedCaptures().SelectMany(kvp => kvp.Value))
{
engine.AddCapture(capture.Number, capture.Index, capture.Value);
}
var modifier = GetModifier(outerEngine);
bool match = false;
yield return(ParseStep.StartLookaround(this, engine.State.Plus(modifier)).WithSkipAdvanceOnFail(ShouldSkipAdvance));
foreach (var result in _regex.Parse(engine))
{
// Don't report the results of the non-reporting start of string element.
if (ReferenceEquals(result.Node, _nonReportingNode))
{
continue;
}
if (ReferenceEquals(result.Node, _regex))
{
if (result.Type == ParseStepType.Match)
{
match = true;
break;
}
if (result.Type == ParseStepType.Fail)
{
continue;
}
if (result.Type == ParseStepType.Break)
{
break;
}
}
if (result.Type != ParseStepType.Break && engine.State.Index <= engine.Input.Length)
{
yield return(result
.ConvertToOuterContext(outerEngine.Input, modifier, this, n => ReferenceEquals(n, _regex), message => message.Replace(_regex.NodeType, NodeType))
.AsLookaround()
.WithSkipAdvanceOnFail(ShouldSkipAdvance));
}
}
if (match)
{
if (!Negative)
{
// TODO: we need to forward any captures from the look-around to the outer engine.
yield return(ParseStep.Pass(this, "", outerEngine.State, engine.State.Plus(modifier)).WithSkipAdvanceOnFail(ShouldSkipAdvance));
}
else
{
yield return(ParseStep.Fail(this, outerEngine.State, engine.State.Plus(modifier)).WithSkipAdvanceOnFail(ShouldSkipAdvance));
}
}
else
{
if (!Negative)
{
yield return(ParseStep.Fail(this, outerEngine.State, engine.State.Plus(modifier)).WithSkipAdvanceOnFail(ShouldSkipAdvance));
}
else
{
// TODO: we need to forward any captures from the look-around to the outer engine.
yield return(ParseStep.Pass(this, "", outerEngine.State, engine.State.Plus(modifier)).WithSkipAdvanceOnFail(ShouldSkipAdvance));
}
}
yield return(ParseStep.EndLookaround(this).WithSkipAdvanceOnFail(ShouldSkipAdvance));
yield return(ParseStep.Break(this).WithSkipAdvanceOnFail(ShouldSkipAdvance));
}