in reply to Custom, Reusable Sort Subroutine for Hashes?

#!/usr/bin/perl use warnings; use strict; use feature qw{ say }; sub sort_hash (&\%) { my ($sub, $hash) = @_; sort { local($a, $b) = @$hash{$a, $b}; $sub->() } keys %$hash } my %hash = ( second => 2, fourth => 4, third => 3, first => 1 ); say for sort_hash { $a <=> $b } %hash;

I used a prototype to make the syntax of sort_hash similar to that of sort. The trick is replacing the magical variables $a and $b with the respective values from the hash.

Update: explanation added.

($q=q:Sq=~/;[c](.)(.)/;chr(-||-|5+lengthSq)`"S|oS2"`map{chr |+ord }map{substrSq`S_+|`|}3E|-|`7**2-3:)=~y+S|`+$1,++print+eval$q,q,a,

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Re^2: Custom, Reusable Sort Subroutine for Hashes?
by QM (Parson) on Aug 30, 2017 at 12:45 UTC
    This is very good, thanks.

    Just as an extension, can I use this with a named sort sub? I expect so, but I'll have to go off and experiment.

    -QM
    --
    Quantum Mechanics: The dreams stuff is made of

      > can I use this with a named sort sub?

      Sure, but you can't use the nice syntax anymore:

      sub numerically { $a <=> $b } say for sort_hash(\&numerically, %hash);
      ($q=q:Sq=~/;[c](.)(.)/;chr(-||-|5+lengthSq)`"S|oS2"`map{chr |+ord }map{substrSq`S_+|`|}3E|-|`7**2-3:)=~y+S|`+$1,++print+eval$q,q,a,
        > but you can't use the nice syntax anymore:

        > say for sort_hash(\&numerically, %hash);

        well you don't need the braces

        say for sort_hash \&numerically, %hash ;

        and this works too

        say for sort_hash {numerically} %hash ;

        Cheers Rolf
        (addicted to the Perl Programming Language and ☆☆☆☆ :)
        Je suis Charlie!