private static ClassExpression Class(INode node)
{
var parts = new List <ClassPartExpression>();
foreach (var part in node.Children.Skip(1))
{
switch (part.Name)
{
case "range":
parts.Add(ClassRangeExpression.From(part,
Char.ConvertToUtf32(DecodeChar(part[0]), 0),
Char.ConvertToUtf32(DecodeChar(part[1]), 0)));
break;
default:
parts.Add(ClassCharExpression.From(part, Char.ConvertToUtf32(DecodeChar(part), 0)));
break;
}
}
return(ClassExpression.From(node, node[0].Count != 0, parts));
}
private ClassPartExpression SingleOrRange(INode node)
{
if (node.Name == "single")
{
Debug.Assert(node.Count == 1);
var c = Character(node[0]);
Debug.Assert(c.Length == 1);
return(ClassCharExpression.From(node, c[0]));
}
else if (node.Name == "range")
{
Debug.Assert(node.Count == 2);
var c1 = Character(node[0]);
Debug.Assert(c1.Length == 1);
var c2 = Character(node[1]);
Debug.Assert(c2.Length == 1);
return(ClassRangeExpression.From(node, c1[0], c2[0]));
}
throw new NotImplementedException();
}
protected override void VisitClassCharExpression(ClassCharExpression expression)
{
Writer.Write($"{expression.Value.InClass()}");
}
protected override void VisitClassCharExpression(ClassCharExpression expression)
{
// handled by VisitClassExpression
throw new NotImplementedException();
}
protected override void VisitClassCharExpression(ClassCharExpression expression)
{
Push(new SingleChar(expression.Value));
}
protected override void VisitClassCharExpression(ClassCharExpression expression)
{
base.VisitClassCharExpression(expression);
SetNullable(expression, false);
}
