That's good to know, thanks.

Which version are you checking this on? And do you know if this is a recent change?

I ask because I had at least one situation where for (@array){...} definitly (seemed to?) caused a very large list to be built. At least, that's what my testing (basically watching the memory grow) showed under 5.6.1.

Update Seems I didn't keep the script, and I can't seem to reproduce the behaviour either.

I'm looking now to see if I can locate the program.

I assume that you're determining this by looking at the opcodes (as is your want:)?

That's "wont". Its a different word. I tested this on 5.6.1 withe following programs. In all cases the list op was removed from the execution path (so named as 'ex-list'). Now from the use of pushmark I infer there's some stack muckery so maybe while list() isn't doing anything, perhaps there is some other form of listification going on here. I'm not motivated enough to break out gdb to find out.

perl -MO=Concise -e 'for(@_){print}'
perl -MO=Concise -e 'for(@A,@B){print}'
perl -MO=Concise -e 'for(@A,@B,1){print}'
[download]

Wow, I've never seen that before. Is there anyplace I can find better documentation on this than B::Concise? I got an idea what was going on, but I don't really know how to interpret the various opcodes...

Thanks for any pointers!