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Re^2: extracting columns

by polettix (Vicar)
on Mar 22, 2012 at 23:10 UTC ( #961121=note: print w/ replies, xml ) Need Help??


in reply to Re: extracting columns
in thread extracting columns

When there are few fields, I usually prefer to avoid slicing and be more direct:

my (undef, $name, undef, $size) = split /\t/;
or even the full stuff
my ($id, $name, $effects, $size) = split /\t/;
I find it a bit more readable but... it's a matter of taste!

perl -ple'$_=reverse' <<<ti.xittelop@oivalf

Io ho capito... ma tu che hai detto?


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Re^3: extracting columns
by Marshall (Prior) on Mar 25, 2012 at 19:02 UTC
    I find it a bit more readable but... it's a matter of taste!

    Don't declare "my" variables that you do not use.

    Use a regex when you want to "keep" something.
    Use split when you want to "throw away something"

    Use list slice to "throw away" extraneous stuff from a split() or a match "global".

    my ($id, $name, $effects, $size) = split /\t/; #wrong
    Forget even declaring, for example, $effects if it is not used.
    Focus the code on what is used from the input - forget the stuff that is not used.
    Explain what $effects would have meant - but its not important to this code - in some kind of comment section - if that this important to the overall description of the input file.

    The use of "undef" instead of list slice is just fine for a case like this.
    List slice is great when you want #12, #3, #1, #50-67 in that order.

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