Re^2: Perl oddities (s/// doesn't DWIM in map)

A related oddity is that map can modify its input, in addition to generating output. That leads to the pitfall of

my @new = map { s/foo/bar/; $_ } @old;
# @old is modified along with @new!
# should be my @new = map { s/foo/bar/; $_ } map {$_} @old;
[download]

If map couldn't modify its input, the whole "map in a void context" debate might never have happened. for would be used for modifying input, map would be used for generating new output. Of course, it's a tradeoff, giving up some liberty for safety.

Caution: Contents may have been coded under pressure.

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Re^3: Perl oddities (s/// doesn't DWIM in map) by ikegami (Patriarch) on Mar 01, 2005 at 22:59 UTC
`my @new = map { local $_ = $_; s/foo/bar/; $_ } @old;` also avoids the problem. Probably faster than using two `map`s, too. Still ugly, unfortunately.	[reply] [d/l] [select]
Re^3: Perl oddities (s/// doesn't DWIM in map) by Aristotle (Chancellor) on Nov 19, 2005 at 09:02 UTC
I write that as `s/foo/bar/ for my @new = @old;` [download] Makeshifts last the longest.	[reply] [d/l]