Re^2: map vs for\foreach.

You right. But..

foreach(@a){$_+=1;};


real    0m3.756s
user    0m3.588s
sys    0m0.120s
[download]

map{$_+= 1} @a;

real    0m5.233s
user    0m5.056s
sys    0m0.164s
[download]

Comment on Re^2: map vs for\foreach. Select or Download Code

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Re^3: map vs for\foreach. by LanX (Saint) on Mar 11, 2015 at 14:36 UTC
Sorry I misunderstood your question (see update in meantime), but it can still be the same effect that `for` tries to be clever and iterates @a, while `map` is flattening. Output with `perl -MO=Terse` seems to indicate this... Cheers Rolf _{(addicted to the Perl Programming Language and ☆☆☆☆ :)} PS: Je suis Charlie!	[reply] [d/l] [select]
Re^4: map vs for\foreach. by ikegami (Patriarch) on Mar 13, 2015 at 17:35 UTC
`for (@a)` is indeed optimized to not place the elements of `@a` on the stack. `for ((),@a)` would prevent the optimization.	[reply] [d/l] [select]
Re^4: map vs for\foreach. by builat (Monk) on Mar 11, 2015 at 14:40 UTC
Thx. For this info. It new for me.	[reply]
Re^5: map vs for\foreach. by LanX (Saint) on Mar 11, 2015 at 14:56 UTC
> It new for me. Not sure if I was able to help you, this area of implementation details is a moving target. And the margins you benchmarked do not really justify any micro-optimisations here, because different Perl versions can behave differently. Personally I'd rather prefer `for` to alter an array via alias, such side-effects in `map` might confuse other readers (a map in void context used to be a matter of warning) Cheers Rolf _{(addicted to the Perl Programming Language and ☆☆☆☆ :)} PS: Je suis Charlie!	[reply]