protected override object OnRuleExpression(INonterminalToken token)
{
if (token == null)
{
throw new ArgumentNullException(nameof(token));
}
var expression = Visit <IExpression>(token[0]);
var children = token.Nonterminal(1).Children;
if (children.Count > 0)
{
var expressions = new List <IExpression> {
expression
};
foreach (var child in children)
{
expressions.Add(Visit <IExpression>(child));
}
expression = new Alternates(expressions);
}
return(expression);
}
protected override object OnGrammarRules(INonterminalToken token)
{
if (token == null)
{
throw new ArgumentNullException(nameof(token));
}
return(token.Nonterminal(0).Children.Select(Visit <NonterminalRule>).ToArray());
}
protected override object OnRuleSequence(INonterminalToken token)
{
var children = token.Nonterminal(0).Children;
var expressions = children.Select(Visit <IExpression>).ToArray();
if (expressions.Length > 1)
{
return(new Sequence(expressions));
}
return(expressions[0]);
}
protected override object OnGrammar(INonterminalToken token)
{
Debug.Assert(token[0].Symbol.Id == LinguId.Identifier);
var grammar = new RawGrammar(token.Terminal(0).Value);
foreach (var section in token.Nonterminal(1).Children)
{
var children = Visit <IReadOnlyList <Symbol> >(section);
grammar.Options.AddRange(children.OfType <Option>());
grammar.Terminals.AddRange(children.OfType <TerminalRule>());
grammar.Nonterminals.AddRange(children.OfType <NonterminalRule>());
}
return(grammar);
}
protected override object OnTerminalSequence(INonterminalToken token)
{
if (token == null)
{
throw new ArgumentNullException(nameof(token));
}
var children = token.Nonterminal(0).Children;
var expressions = children.Select(Visit <IExpression>).ToArray();
if (expressions.Length > 1)
{
return(new Sequence(expressions));
}
return(expressions[0]);
}
protected override object OnTerminalExpression(INonterminalToken token)
{
var expressions = new List <IExpression>()
{
Visit <IExpression>(token[0])
};
var children = token.Nonterminal(1).Children;
expressions.AddRange(children.Select(Visit <IExpression>));
if (expressions.Count > 1)
{
return(new Alternates(expressions));
}
return(expressions[0]);
}
protected override object OnTerminalRangeLoop(INonterminalToken token)
{
var expression = Visit <IExpression>(token[0]);
var range = token.Nonterminal(1).Children;
var x1 = Visit <Integer>(range[0]);
var rest = ((INonterminalToken)range[1]).Children;
if (rest.Count == 0)
{
return(Repeat.From(expression, x1.Value, x1.Value));
}
var x2 = Visit <Integer>(rest[0]);
return(Repeat.From(expression, x1.Value, x2.Value));
}
protected override object OnGrammarRules(INonterminalToken token)
{
return(token.Nonterminal(0).Children.Select(Visit <NonterminalRule>).ToArray());
}