in reply to Re^2: map vs for\foreach.
in thread map vs for\foreach.

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!

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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.
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.
      > 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!