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Re: Replacing whitespaces with a regex

by ISAI student (Scribe)
on Mar 04, 2013 at 16:24 UTC ( #1021672=note: print w/ replies, xml ) Need Help??


in reply to Replacing whitespaces with a regex

There is, of course, more than 1 to do it. My favorite is:

map {s/\s+$/ /} @array;
It uses the @array, which makes the code more readable, and PERL's great map function for 1 liners.


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Re^2: Replacing whitespaces with a regex
by choroba (Abbot) on Mar 04, 2013 at 16:44 UTC
    map in a void context can be replaced by for:
    s/\s+$/ / for @array;
    لսႽ ᥲᥒ⚪⟊Ⴙᘓᖇ Ꮅᘓᖇ⎱ Ⴙᥲ𝇋ƙᘓᖇ
      Yes. But map brings me memories of the times I got to know the PERL magic, +and more than 1 way to do it. If I use for or foreach, I feel like I +use TCL/Python, and not enjoying an experience unique to PERL. map seems, to me, as more decidedly PERLISH that for. It's a personal thing, and this is why I have said that it is a person +al prefernce (unless there is a performance consideration).

        I'm a huge fan of map, but I wouldn't use it that way. Most recommendations on Perl best practices that I've seen suggest against map in void context (using for/foreach instead), and I think that one makes a lot of sense.

        When I see map, I expect that it is being used in the conventional higher-order function way: taking a list, applying a given function to each item in the list, and returning the resulting list. The original array isn't changed.

        This gives me a strong visual cue when I'm reading code: if I see map, it's creating a (modified) copy of a list, if I see for/foreach loop, then I'm making a change to the list itself. I would go so far as to say that these are the fairly standard (in so far as Perl has standards) and idiomatic way of using map and for/foreach.

        Just as a historical side-note, map isn't a Perl creation; it comes from the world of functional programming. This is also where the recommended usage (as suggested above) comes from, as that is how it is used in most languages. Many languages have a map function (including Python).

        You are, of course, free to use it any way you want, but don't be surprised if most programmers (especially those familiar with functional programming) expect it to be used as described above.

        Christopher Cashell

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