public virtual Expression VisitComprehension(Comprehension comprehension)
{
if (comprehension == null) return null;
comprehension.BindingsAndFilters = this.VisitExpressionList(comprehension.BindingsAndFilters);
comprehension.Elements = this.VisitExpressionList(comprehension.Elements);
return comprehension;
}
public override Expression VisitComprehension(Comprehension Comprehension)
{
if (Comprehension == null) return null;
return base.VisitComprehension((Comprehension)Comprehension.Clone());
}
public Quantifier(NodeType t, Comprehension comprehension)
: base(NodeType.Quantifier)
{
this.QuantifierType = t;
this.Comprehension = comprehension;
}
private Comprehension ParseComprehension(TokenSet followers, SourceContext sctx){
bool isDisplay = true;
ExpressionList bindingAndFilterList = new ExpressionList();
ExpressionList elementList = new ExpressionList();
Expression e = null;
if (this.currentToken != Token.RightBrace){
e = this.ParseIteratorOrExpression(followers|Token.RightBrace|Token.Semicolon|Token.Comma);
if (e == null){
this.HandleError(sctx, Error.SyntaxError,"iterator or expression");
return null;
}else{
bindingAndFilterList.Add(e);
}
isDisplay = !(e is ComprehensionBinding);
while (this.currentToken == Token.Comma){
this.GetNextToken();
e = this.ParseIteratorOrExpression(followers|Token.RightBrace|Token.Semicolon|Token.Comma);
if (e == null){
this.HandleError(sctx, Error.SyntaxError,"iterator or expression");
return null;
} else {
bindingAndFilterList.Add(e);
}
if (isDisplay)
isDisplay = !(e is ComprehensionBinding);
}
if (!isDisplay) {
if (this.currentToken != Token.Semicolon) {
this.SkipTo(followers, Error.InvalidExprTerm, this.scanner.GetTokenSource());
} else {
this.GetNextToken();
Expression temp = this.ParseExpression(followers | Token.RightBrace | Token.Semicolon);
if (temp != null)
elementList.Add(temp);
if (this.currentToken == Token.Semicolon) {
this.GetNextToken();
this.Skip(Token.Default);
temp = this.ParseExpression(followers | Token.RightBrace);
if (temp != null)
elementList.Add(temp);
}
}
}
}
sctx.EndPos = this.scanner.endPos;
this.Skip(Token.RightBrace);
if (isDisplay){ // display, what we thought were bindings/filters are actually all elements
elementList = bindingAndFilterList;
bindingAndFilterList = null;
}
Comprehension comp = new Comprehension();
if (bindingAndFilterList != null && bindingAndFilterList.Count > 0)
comp.BindingsAndFilters = bindingAndFilterList;
comp.Elements = elementList;
this.sawReturnOrYield = true;
comp.SourceContext = sctx;
comp.SourceContext.EndPos = this.scanner.CurrentSourceContext.StartPos;
this.SkipTo(followers);
return comp;
}
public EventingVisitor(Action<Comprehension> visitComprehension) { VisitedComprehension += visitComprehension; } public event Action<Comprehension> VisitedComprehension; public override Expression VisitComprehension(Comprehension comprehension) { if (VisitedComprehension != null) VisitedComprehension(comprehension); return base.VisitComprehension(comprehension); }