public bool Scan(char c)
{
// get expected lexemes
var expectedLexemes =
from rule in _parseEngine.GetExpectedLexerRules()
where rule.LexerRuleType == TerminalLexerRule.TerminalLexerRuleType
let terminalRule = rule as ITerminalLexerRule
select new TerminalLexeme(terminalRule);
// filter on first rule to pass (since all rules are one character per lexeme)
// PERF: Avoid Linq FirstOrDefault due to lambda allocation
TerminalLexeme firstPassingRule = null;
foreach (var lexeme in expectedLexemes)
if (lexeme.Scan(c))
{
firstPassingRule = lexeme;
break;
}
if (firstPassingRule == null)
return false;
var token = new Token(firstPassingRule.Capture, _parseEngine.Location, firstPassingRule.TokenType);
var result = _parseEngine.Pulse(token);
if (result)
_capture.Append(c);
return result;
}
private IForestNode CreateNullParseNode(ISymbol symbol, int location)
{
var symbolNode = _nodeSet.AddOrGetExistingSymbolNode(symbol, location, location);
var token = new Token(string.Empty, location, new TokenType(string.Empty));
var nullNode = new TokenForestNode(token, location, location);
symbolNode.AddUniqueFamily(nullNode);
return symbolNode;
}
public override void Visit(ITerminalForestNode terminalNode)
{
var token = new Token(
terminalNode.Capture.ToString(),
terminalNode.Origin,
new TokenType(terminalNode.ToString()));
VisitToken(terminalNode.Origin, terminalNode.Location, token);
}
