about_sort.pl

#!/usr/bin/perl
=pod
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=cut

package Perl::Koans::Sort;
use warnings;

use lib './lib';
use Perl::Koans;


################
# your code goes below this line

sub about_sort {
    # about_sort() - sort, reverse

    my @unsorted_nums  = (3, 1, 2);
    my @unsorted_chars = ('c', 'd', 'o');
    my @unsorted_mix   = ('a', 1, 'b', 2, 'c', 3);

    my @sorted_nums = sort @unsorted_nums;

    is_deeply (\@sorted_nums,          [1, 2, 3], 'sort(list) returns contents of list in ASCIIbetical order'); # TODO: where else do we need to replace is with is_deeply() ?, also need to overload this function in Perl::Koans 
    is_deeply ([sort @unsorted_chars], __, 'sort(list) returns contents of list in ASCIIbetical order -- part 2');
    is_deeply ([sort @unsorted_mix],   __, 'sort(list) returns contents of list in ASCIIbetical order -- part 3');
    
    my %h = (
        one   => 1,
        two   => 2,
        three => 3,
    );
    
    is_deeply ([sort keys %h],   __, 'sort(list) returns contents of list in ASCIIbetical order -- part 4');
    is_deeply ([sort values %h], __, 'sort(list) returns contents of list in ASCIIbetical order -- part 5');
    
    my @reversed_nums = reverse sort @unsorted_nums;
    is_deeply(\@reversed_nums, __, 'reverse(list) returns list in reverse order'); # TODO how to mention the difference between scalar and array context here? maybe it becomes a model in about_context.pl
    
    ## TODO, probably pull this, is a little advanced
    my @unsortable_array;
    my %phone_numbers = ( emergency => 911, operator => 0 );
    my %addresses     = ( work => '1 Market St' );
    
    push @unsortable_array, \%phone_numbers;
    push @unsortable_array, \%addresses;

    # TODO better comment / test name here
    is_deeply ([sort @unsortable_array], __, 'sort(list) requires that elements in list must be comparable');

    return (Perl::Koans::get_exit_code());
}

sub about_custom_sorts {
    # about_custom_sorts() - only covering inline functions
    
    my @array = ('01', 2, 3, 'a'..'c', 'D');
    is_deeply ([sort { $a cmp $b } @array], __, 'sort { } supports a -1|0|1 comparison block using $a, $b foreach in a list -- cmp is a string comparison'); # this is how Perl does sorting by default -- better hint here
    is_deeply ([sort { $a <=> $b } @array], __, 'sort { } supports a -1|0|1 comparison block using $a, $b foreach in a list -- <=> is a numeric comparison');
    
    fail("write some actually complete tests for custom sorting");
    
    # TODO finish this
    # a multilevel sort example? sort elements in an array according to their hash keys, and then their actual values
    # is_deeply ([], __, 'sort { } supports a -1|0|1 comparison block using $a, $b foreach in ')
    
    # (sort { $a <=> $b } @values )
    # (sort { $a <=> $b } keys %hash)
    # (sort { $hash{$a} <=> $hash{$b} } keys %hash)
    
    
}


# your code goes above this line
################

unless (caller(0)) {
    run(@ARGV) or print_illumination();
    exit();
}

sub run {
    # run() -- runs all functions in this module
    my $results = 0;
    
    about_sort();
    about_custom_sorts();
    
    return ($results) ? bail($results) : $results;
}


1;