[SR-Dev] new operators & if($v) behaviour

Right now we have a problem with old scripts that use things like if ($v) (where $v could be avp, pseudovar or select). $v can evaluate to a int, a string or undefined. Now for string and undefined the if will evaluate to false (string being an error) and an error will be logged. If the type of $v can be found prior to runtime (e.g. @select is always string) you'll even get a parse error. I plan to add some new operators, to properly deal with these cases: defined($v) strempty($v) strlen($v) but the question still remains if we should preserve compatibility and still support things like if (@to.tag), instead of if (!strempty((a)to.tag)) or if (@to.tag!=""). What's trickier is that if we allow strings in int expressions then we have 2 problems: - "" evaluates to 1 or 0? - how to evaluate a string in an integer context: is "abc" 1 or 3 (strlen)? How about "123" ? - $v is 0 if v is not defined? Note that if we do this it will work in all types of expressions, e.g. if string evaluates to strlen(string) in interger context then: 3+"abc" = 6 ; 3+ ""=3 ; 3+"9"=4 3+"0"=4. Andrei