public static bool TryParseRuralRouteBox(string input, out RuralRouteBoxSyntaxNode result)
{
var tokens = Tokenizer.Tokenize(input).Reverse().ToImmutableArray();
var state = new ParserState(tokens);
var success = TryParseRuralRouteBox(ref state, out var syntax) && state.Current.IsNone;
result = success ? syntax : null;
return(success);
}
private static bool TryParseRuralRouteBox(ref ParserState state, out RuralRouteBoxSyntaxNode result)
{
result = null;
var snapshot = state;
RangeSyntaxNode routeNumber;
ImmutableArray <Token> boxKeywordTokens;
if (TryParseRange(ref state, out var boxNumber))
{
state.ConsumeWhiteSpace();
if (state.TryConsume(t => t.IsOctothorpe))
{
state.ConsumeWhiteSpace();
}
if (state.TryConsume("box"))
{
state.ConsumeWhiteSpace();
if (state.TryConsume(t => t.IsCommaOrPeriod))
{
state.ConsumeWhiteSpace();
}
boxKeywordTokens = state.TakeBuffer();
if (TryParseRange(ref state, out routeNumber))
{
state.ConsumeWhiteSpace();
if (state.TryConsume(t => t.IsOctothorpe))
{
state.ConsumeWhiteSpace();
}
if (state.TryConsume(t => t.IsCommaOrPeriod))
{
state.ConsumeWhiteSpace();
}
if (state.TryConsume(t => t.Matches("rr") || t.Matches("rd") || t.Matches("rfd")))
{
goto Parsed;
}
else if (state.TryConsume("r"))
{
state.ConsumeWhiteSpace();
if (state.TryConsume(t => t.IsCommaOrPeriod))
{
state.ConsumeWhiteSpace();
}
if (state.TryConsume("r"))
{
goto Parsed;
}
}
else if (state.TryConsume(t => t.Matches("route") || t.Matches("rt")))
{
state.ConsumeWhiteSpace();
state.TryConsume("rural");
goto Parsed;
}
}
}
}
state = snapshot;
return(false);
Parsed:
result = new RuralRouteBoxSyntaxNode(
state.TakeBuffer(),
routeNumber,
boxKeywordTokens,
boxNumber);
return(true);
}
