In my opinion (or "I personally believe" if you must) modifying an array with push/pop inside a map statement is one of those hints that there's a better way to go about a problem! :-)

The canonical form of map (according to me) is used to return a mapped version of the input: 

@a = map {
    # A function of $_, eg:
    $_ . ".txt"
} @a;

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One of the things I find particularly useful is that the block of code can evaluate to a list, including an empty one. Ie the output of map need not be the same length as the input. Eg 
# Emulate grep with map
@a = map { elementShouldBeIncluded($_) ? $_ : () } @a;

# Double up the list
@a = map { ($_, $_) } @a;

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In this particular case, this feature may be exactly what you're after, depending on how what exactly your vendor supplied program does. Consider the following structure: 

@a = map {
    # Is it a dir?
    (-d $_) ?
        # Expand it (somehow) into a list of files
        turnDirIntoFilesUsingVendorProg($_)
    :
        # It's a file - pass it straight through
        $_
} @a;

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Hope that helps.

In reply to Re: Unshift and push inside of map operation. by wol
in thread Unshift and push inside of map operation. by LNEDAD

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