Ast.SetNode ParseSet(SeekableStringReader sr)
{
// set = '{' expr_list '}' .
sr.Read(); // {
sr.SkipWhitespace();
Ast.SetNode setnode = new Ast.SetNode();
List <Ast.INode> elts = ParseExprList(sr);
if (!sr.HasMore())
{
throw new ParseException("missing '}'");
}
char closechar = sr.Read();
if (closechar != '}')
{
throw new ParseException("expected '}'");
}
// make sure it has set semantics (remove duplicate elements)
HashSet <Ast.INode> h = new HashSet <Ast.INode>(elts);
setnode.Elements = new List <Ast.INode>(h);
return(setnode);
}
public void Visit(Ast.SetNode setnode)
{
HashSet <object> obj = new HashSet <object>();
foreach (Ast.INode node in setnode.Elements)
{
node.Accept(this);
obj.Add(generated.Pop());
}
generated.Push(obj);
}
public void Visit(Ast.SetNode setnode)
{
result.AppendLine("(set");
indent++;
foreach (Ast.INode node in setnode.Elements)
{
Indent();
node.Accept(this);
result.AppendLine(",");
}
indent--;
Indent();
result.Append(")");
}
private Ast.SetNode ParseSet(SeekableStringReader sr)
{
// set = '{' expr_list trailing_comma '}' .
// trailing_comma = '' | ',' .
sr.Read(); // {
sr.SkipWhitespace();
Ast.SetNode setnode = new Ast.SetNode();
var elts = ParseExprList(sr);
// handle trailing comma if present
sr.SkipWhitespace();
if (!sr.HasMore())
{
throw new ParseException("missing '}'");
}
if (sr.Peek() == ',')
{
sr.Read();
}
if (!sr.HasMore())
{
throw new ParseException("missing '}'");
}
char closechar = sr.Read();
if (closechar != '}')
{
throw new ParseException("expected '}'");
}
// make sure it has set semantics (remove duplicate elements)
var h = new HashSet <Ast.INode>(elts);
setnode.Elements = new List <Ast.INode>(h);
return(setnode);
}
