use v6.d;

module Sub::Memoized:ver<0.0.5>:auth<zef:lizmat> {

    # Create the identification string for the capture to serve as key
    my sub fingerprint(Capture:D $capture --> Str:D) {
        my str @parts = $capture.list.map: *<>.WHICH.Str;
        @parts.push('|');  # don't allow positionals to bleed into nameds
        for $capture.hash -> $pair {
            @parts.push( $pair.key );  # key is always a string with nameds
            @parts.push( $pair.value<>.WHICH.Str );
        }
        @parts.join('|')
    }

    # Perform the actual wrapping of the sub to have it memoized
    my sub memoize(\r, \cache --> Nil) {
        r.wrap(-> |c {
            my $key := fingerprint(c);
            cache.EXISTS-KEY($key)
              ?? cache.AT-KEY($key)
              !! cache.BIND-KEY($key,callsame);
        });
    }

    # Handle the "is memoized" / is memoized(Bool:D) cases
    multi sub trait_mod:<is>(Sub:D \r, Bool:D :$memoized! --> Nil) is export {
        if $memoized {
            my $name = r.^name;
            memoize(r, {});
            r.WHAT.^set_name("$name\(memoized)");
        }
    }

    # Handle the "is memoized(my %h)" case
    multi sub trait_mod:<is>(Sub:D \r, Hash:D :$memoized! --> Nil) is export {
        my $name = r.^name;
        memoize(r, $memoized<>);
        r.WHAT.^set_name("$name\(memoized)");
    }
}



head

Sub::Memoized - trait for memoizing calls to subroutines


sub a($a,$b) is memoized {
    # do some expensive calculation
}


sub b($a, $b) is memoized( my %cache ) {
    # do some expensive calculation with direct access to cache
}


use Hash::LRU;
sub c($a, $b) is memoized( my %cache is LRU( elements => 2048 ) ) {
    # do some expensive calculation, keep last 2048 results returned
}


Sub::Memoized provides a C<is memoized> trait on C<Sub>routines as an easy
way to cache calculations made by that subroutine (assuming a given set of
input parameters will always produce the same result).


Optionally, you can specify a hash that will serve as the cache.  This
allows later access to the generated results.  Or you can specify a specially
crafted hash, such as one made with C<Hash::LRU>.


Source can be located at: https://github.com/lizmat/Sub-Memoized . Comments and
Pull Requests are welcome.


This library is free software; you can redistribute it and/or modify it under
the Artistic License 2.0.


root

README

React

=begin React :component<HeaderCol> :id<menu> 
=para L<Documentation|/doc/introduction>
=para L<Modules| /mods>
=para L<Examples| file:../examples/index.podlite>
=para L<Download |file:../download/index.podlite>
=para L<About|file:../about/index.podlite>
=para 🔍 K<⌘K>/K<ctrl-K>
=end React


=begin React :component<HeaderCol> :id<footer>  
=begin nested :!nested
=item1 B<Language>
    =item2 L<Get started|file:../getting-started/getting-started.podlite>
    =item2 L<Why Raku?|/doc/language/faq#Why-should-I-learn-Raku-What's-so-great-about-it>
    =item2 L<Try Raku|https://glot.io/new/raku>
    =item2 L<Raku cheat sheet|https://github.com/Raku/mu/blob/master/docs/Perl6/Cheatsheet/cheatsheet.txt>
    =item2 L<empty|#>
    =item2 L<empty|#>
    =item2 L<empty|#>
    =item2 L<Raku on Exercism|https://exercism.org/tracks/raku>
    =item2 L<Wikipedia|https://en.wikipedia.org/wiki/Raku_(programming_language)>
    =item2 L<empty|#>
    =item2 L<empty|#>
    =item2 L<empty|#>

=end nested
=begin nested :!nested

=item1 B<L<Documentation|/doc>>
    =item2 L<Getting started, Migration guides from other languages, & Tutorials | file:../doc/introduction.podlite>
    =item2 L<Language References|file:../doc/reference.podlite>
    =item2 L<Type Reference| file:../doc/types.podlite>
    =item2 L<Miscellaneous| file:../doc/miscellaneous.podlite>
    =item2 L<FAQs (Frequently Asked Questions)|/doc/language/faq>
    =item2 L<Community|/doc/language/community>
    =item2 L<The list of all documents|file:../doc/index.podlite>

=item1 B<Resources>
    =item2 L<The Raku Guide|https://raku.guide/>
    =item2 L<Books |https://perl6book.com/>
    =item2 L<Rosetta Code | https://www.raku.org/community/rosettacode>

=end nested
=begin nested :!nested

=item1 B<Resoures>
    =item2 L<Download | file:../download/index.podlite>
    =item2 L<empty|#>
    =item2 L<empty|#>
    =item2 L<empty|#>
    =item2 L<empty|#>
    =item2 L<empty|#>
    =item2 L<empty|#>
    =item2 L<empty|#>

=item1 B<Learning>
    =item2 L<The Raku Guide|https://raku.guide/>
    =item2 L<Wikibook |https://en.wikibooks.org/wiki/Raku_Programming>
    =item2 L<Books |https://perl6book.com/>
    =item2 L<Rosetta Code | https://www.raku.org/community/rosettacode>
    =item2 L<Learn Raku in Y minutes|https://learnxinyminutes.com/docs/raku/>
    =item2 L<Golfing |https://github.com/AlexDaniel/raku-golf-cheatsheet>
=end nested
=begin nested :!nested

=item1 B<Explore>
    =item2 L<Raku Blog Aggregator|https://planet.raku.org/>
    =item2 L<Rakudo Weekly|https://rakudoweekly.blog/>
    =item2 L<The Weekly Challenge |https://perlweeklychallenge.org/>
    =item2 L<Raku Advent Calendar|https://raku-advent.blog/>
    =item2 L<empty|#>
    =item2 L<empty|#>
    =item2 L<empty|#>
    =item2 L<empty|#>
    =item2 L<empty|#>

=end nested
=end React


=begin React :component<CookieConsent> :id<CookieConsent> :buttonCaption("Got it!")
=para
This website uses cookies for analytics.
=end React


Memoized

NAME

SYNOPSIS

DESCRIPTION

AUTHOR

COPYRIGHT AND LICENSE

Sub::Memoized v0.0.5

Authors

License

Dependencies

Test Dependencies

Provides

Documentation