public override MSAst.Expression Reduce()
{
MSAst.ParameterExpression list = Ast.Parameter(typeof(List), "list_comprehension_list");
// 1. Initialization code - create list and store it in the temp variable
MSAst.Expression initialize =
Ast.Assign(
list,
Ast.Call(AstMethods.MakeList)
);
// 2. Create body from _item: list.Append(_item)
MSAst.Expression body = GlobalParent.AddDebugInfo(
Ast.Call(
AstMethods.ListAddForComprehension,
list,
AstUtils.Convert(_item, typeof(object))
),
_item.Span
);
// 3. Transform all iterators in reverse order, building the true body:
int current = _iterators.Length;
while (current-- > 0)
{
ListComprehensionIterator iterator = _iterators[current];
body = iterator.Transform(body);
}
return(Ast.Block(
new[] { list },
initialize,
body,
list // result
));
}
public ListComprehension(Expression item, ListComprehensionIterator[] citers)
{
this.item = item; this.iters = citers;
}
public ListComprehension(Expression item, ListComprehensionIterator[] iterators) {
_item = item;
_iterators = iterators;
}