Solution to task 2

1 files changed, 130 insertions, 0 deletions

diff --git a/challenge-305/jo-37/perl/ch-2.pl b/challenge-305/jo-37/perl/ch-2.pl
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+++ b/challenge-305/jo-37/perl/ch-2.pl
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+#!/usr/bin/perl -T
+
+use v5.26;
+use Test2::V0;
+use Test2::Tools::Subtest 'subtest_streamed';
+use Getopt::Long;
+use Unicode::Normalize;
+use warnings FATAL => 'all';
+use Data::Dump qw(dd pp);
+use experimental 'signatures';
+use utf8;
+
+### Options and Arguments
+
+my ($tests, $examples, $verbose, $order);
+GetOptions(
+    'examples!' => \$examples,
+    'tests!'    => \$tests,
+    'verbose!'  => \$verbose,
+    'order=s'   => \$order,
+) or usage();
+
+run_tests($examples, $tests);	# tests do not return
+
+usage() unless @ARGV;
+
+sub usage {
+    die <<~EOS;
+    $0 - alien sort
+
+    usage: $0 [-examples] [-tests] [-order C,... W...]
+
+    -examples
+        run the examples from the challenge
+     
+    -tests
+        run some tests
+
+    -order C,...
+        comma and/or whitspace separated list of characters 'a' .. 'z'
+
+    W...
+        list of words
+
+    EOS
+}
+
+
+### Input and Output
+
+say "@{[alien_sort([split /[,\s]\s*/, $order], @ARGV)]}";
+
+
+### Implementation
+#
+# For details see:
+# https://github.sommrey.de/the-bears-den/2025/01/24/ch-305.html#task-2
+
+BEGIN {
+    my @all = 'a' .. 'z';
+
+    sub alien_sort ($order, @words) {
+        my %a2n;
+        @a2n{@$order} = @all;
+        die 'order not valid' if @all > grep defined, @a2n{@all};
+        my %n2a = map {$a2n{$_} => $_} @all;
+        my $alien = join '', @n2a{@all};
+
+        map $_->[0],
+            sort {$a->[1] cmp $b->[1]}
+            map {
+                [$_, eval "NFD(fc) =~ tr/a-z//cdr =~ tr/$alien/a-z/r"]
+            } @words;
+    }
+}
+
+
+### Examples and Tests
+
+sub run_tests ($examples, $tests) {
+    return unless $examples || $tests;
+
+    state sub run_example ($args, $expected, $name) {
+        my $result = [alien_sort(@$args)];
+        my $alien = shift @$args;
+        like $result, $expected,
+            "$name: alien='@$alien' (@$args) -> (@$expected)", $@;
+    }
+
+    plan 2;
+
+    $examples ? subtest_streamed(examples => sub {
+        my @examples = (
+            [[[qw/h l a b y d e f g i r k m n o p q j s t u v w x c z/],
+                    "perl", "python", "raku"],
+                ["raku", "python", "perl"], 'example 1'],
+            [[[qw/c o r l d a b t e f g h i j k m n p q s w u v x y z/],
+                    "the", "weekly", "challenge"],
+                ["challenge", "the", "weekly"], 'example 2'],
+        );
+        plan scalar @examples;
+        for (@examples) {
+            run_example @$_;
+        }
+    }) : pass 'skip examples';
+
+    $tests ? subtest_streamed(tests => sub {
+        plan 5;
+        my $tainted = substr $ENV{PATH}, 0, 0;
+
+        ok lives {alien_sort([map $_ . $tainted, 'a' .. 'z'], 'abc')},
+            'laundered', $@;
+
+        like dies {alien_sort(['//;die-gotcha;tr/a', 'a' .. 'z'], 'abc')},
+            qr/order not valid/, 'missing letter in order';
+
+        ok lives {alien_sort(['a' .. 'z', '//;exit;tr/a-z'],
+                'abc', 'bcd')}, 'ignore injection', $@;
+
+        is [alien_sort([qw(z y a c b), 'd' .. 'x'], qw(ab ac yb zb))],
+            [qw(zb yb ac ab)], 'alien order';
+
+        is [alien_sort([qw(a e i o u b c d f g h j k
+                    l m n p q r s t v w x y z),],
+                'Oc', 'Öc', 'oc', 'öc', 'oe', 'öe', 'Oe', 'Öe')],
+        ['oe', 'öe', 'Oe', 'Öe', 'Oc', 'Öc', 'oc', 'öc'], 'upper and umlauts';
+    }) : pass 'skip tests';
+
+    exit;
+}