raku-rosettacode/programming_tasks/A/Anagram_generator.md

Anagram generator

Using the unixdict.txt word file by default.

unit sub MAIN ($in is copy = '', :$dict = 'unixdict.txt');
 
say 'Enter a word or phrase to be anagramed. (Loading dictionary)' unless $in.chars;
 
# Load the words into a word / Bag hash
my %words = $dict.IO.slurp.lc.words.race.map: { .comb(/\w/).join => .comb(/\w/).Bag };
 
# Declare some globals
my ($phrase, $count, $bag);
 
loop {
    ($phrase, $count, $bag) = get-phrase;
    find-anagram Hash.new: %words.grep: { .value ⊆ $bag };
}
 
sub get-phrase {
    my $prompt = $in.chars ?? $in !! prompt "\nword or phrase? (press Enter to quit) ";
    $in = '';
    exit unless $prompt;
    $prompt,
    +$prompt.comb(/\w/),
    $prompt.lc.comb(/\w/).Bag;
}
 
sub find-anagram (%subset, $phrase is copy = '', $last = Inf) {
    my $remain = $bag ∖ $phrase.comb(/\w/).Bag;        # Find the remaining letters
    my %filtered = %subset.grep: { .value ⊆ $remain }; # Find words using the remaining letters
    my $sofar = +$phrase.comb(/\w/);                   # Get the count of the letters used so far
    for %filtered.sort: { -.key.chars, ~.key } {       # Sort by length then alphabetically then iterate
        my $maybe = +.key.comb(/\w/);                  # Get the letter count of the maybe addition
        next if $maybe > $last;                        # Next if it is longer than last - only consider descending length words
        next if $maybe == 1 and $last == 1;            # Only allow one one character word
        next if $count - $sofar - $maybe > $maybe;     # Try to balance word lengths
        if $sofar + $maybe == $count {                 # It's an anagram
            say $phrase ~ ' ' ~ .key and next;         # Display it and move on
        } else {                                       # Not yet a full anagram, recurse
            find-anagram %filtered, $phrase ~ ' ' ~ .key, $maybe;
        }
    }
}

Punctuation, capitalization and (in some cases) word order manually massaged.

Output:

Enter a word or phrase to be anagramed. (Loading dictionary)

word or phrase? (press Enter to quit) Rosettacode
doctor tease

word or phrase? (press Enter to quit) thundergnat
dragnet hunt
Gent? Nah, turd.

word or phrase? (press Enter to quit) Clint Eastwood
downcast eliot
I contest waldo
nose to wildcat