Re^2: return if 0

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Re^3: return if 0 by zigdon (Deacon) on Jun 22, 2009 at 23:16 UTC
To be fair, it wouldn't be insane for the compiler to know that the block can never execute, and just remove it completely. Except for the part that it has unexpected consequences, as we've been discussing. -- zigdon	[reply]
Re^4: return if 0 by ikegami (Patriarch) on Jun 23, 2009 at 01:02 UTC
It does remove the `if`, but it keeps the constant to maintain the behaviour. `>perl -MO=Concise,-exec,f -e"sub f { return 1 if 0 }" main::f: 1 <;> nextstate(main 1 -e:1) v 2 <$> const[IV 0] s/SHORT 3 <1> leavesub[1 ref] K/REFC,1 -e syntax OK` [download] Compared to: `>perl -MO=Concise,-exec,f -e"sub f { return 1 if $c }" main::f: 1 <;> nextstate(main 1 -e:1) v 2 <#> gvsv[*c] s 3 <\|> and(other->4) K/1 4 <0> pushmark s 5 <$> const[IV 1] s 6 <@> return K 7 <1> leavesub[1 ref] K/REFC,1 -e syntax OK` [download] Note the `and` operator (used to implement `if`) is missing from the first snippet.	[reply] [d/l] [select]
Re^3: return if 0 by FloydATC (Deacon) on Jun 25, 2009 at 11:14 UTC
Perhaps I was a bit unclear; I meant to say the "return" will never happen because 0 will never be true. -- Time flies when you don't know what you're doing	[reply]
Re^4: return if 0 by ikegami (Patriarch) on Jun 25, 2009 at 11:48 UTC
In that case, your post simply didn't answer anything. The OP knew the return wasn't being executed. He was wondering why the following didn't return 1, `print`'s return value. `sub test { print "in test!"; return if 0; }` [download]	[reply] [d/l] [select]