Re^2: To return and/or not?

Replies are listed 'Best First'.
Re^3: To return and/or not? by moritz (Cardinal) on Oct 08, 2011 at 11:21 UTC
It seems to be the general sentiment that if a certain decision bites you, you consider it strange/weird/harmful/whatever, and forget all those idioms that are enabled by it. Yet all language design decisions are tradeoffs, and even generally good decisions bite you sometimes. Go figure. `return` is a normal listop, with normal listop precedence. The looser precedence of and/or/not is exactly the reason for having them. There wouldn't be any reason for them to exist if they had the same precedence as &&/\|\|/!. The only thing perl could do better here is to warn about unreachable code in sub c2; but I think that has been tried before for `if 0 { ... }` code, and has been discarded at not helpful. Perl 6 - second systems done right	[reply] [d/l] [select]
Re^3: To return and/or not? by choroba (Cardinal) on Oct 08, 2011 at 09:50 UTC
Seems a strange decision. Not really. It make the famous `open my $IN, '<', $filename or die "Cannot open $filename: $!\n";` [download] possible.	[reply] [d/l]
Re^4: To return and/or not? by Anonymous Monk on Oct 08, 2011 at 10:10 UTC
How would lowering the precedence of 'return' stop that from working?	[reply]
Re^5: To return and/or not? by choroba (Cardinal) on Oct 08, 2011 at 10:12 UTC
Operators have different precedence, not the commands. See perlop. Updated.	[reply]
Re^3: To return and/or not? by Anonymous Monk on Oct 08, 2011 at 10:13 UTC
So basically the operators... Yeah, `perldoc perlop` indeed says that not/and/or/xor have the lowest precedence left terms and list operators (leftward) left -> nonassoc ++ -- right ** right ! ~ \ and unary + and - left =~ !~ left * / % x left + - . left << >> nonassoc named unary operators nonassoc < > <= >= lt gt le ge nonassoc == != <=> eq ne cmp ~~ left & left \| ^ left && left \|\| // nonassoc .. ... right ?: right = += -= = etc. left , => nonassoc list operators (rightward)* right not left and left or xor Seems a strange decision. How many other programming languages do you know? That have the keywords not/and/or/xor as operators?	[reply]
Re^4: To return and/or not? by Anonymous Monk on Oct 08, 2011 at 10:37 UTC
What other programming languages? OK, I think I get it - its not that return is strange, its that not, and, or , xor are lower precedence than everything else (eg other operators, statements like return, and functions like open). I expected return to be even lower precedence.	[reply]
Re^5: To return and/or not? by Anonymous Monk on Oct 08, 2011 at 10:59 UTC
What other programming languages? That is what I asked you :) What previous programming experience do you have that makes perls precedence order seem strange	[reply]