Perl Weekly Challenge 317: only Raku for now!

This post presents my solutions to the Perl Weekly Challenge 317.
I keep doing the Perl Weekly Challenge in order to mantain my coding skills in good shape, as well as in order to learn new things, with particular regard to Raku, a language that I love.
This week, I solved the following tasks:

• PWC 317 - Task 1 - Raku
• PWC 317 - Task 2 - Raku

Raku Implementations

PWC 317 - Task 1 - Raku Implementation

The first task was to find out if the first letter of a list of words created an acronym passed as argument.

sub MAIN( Str $acronym, *@words where { @words.elems == $acronym.chars } ) {
    'True'.say and exit if ( @words.map( *.fc.comb[ 0 ] ).join ~~ $acronym.fc );
    'False'.say;
}

This is quite simple: I extract all the first char of the given list of @words and join it back to compare with the smart match against the $acronym.

PWC 317 - Task 2 - Raku Implementation

The second task was to find out if exchanging any two characters in a word resulted in the other given word.

sub MAIN( Str $needle, Str $haystack where { $haystack.chars == $needle.chars } ) {
    # short circuit: the strings are the same
    'True'.say if ( $needle.fc ~~ $haystack.fc );

    my $differences = 0;
    my @needle = $needle.lc.comb;
    my @haystack = $haystack.lc.comb;

    for 0 ..^ @needle.elems {
		$differences++ unless ( @needle[ $_ ] eq @haystack[ $_ ] );
    }

    'True'.say and exit if ( $differences == 2 );
    'False'.say;
}

This is quite simple: I keep a list of characters of the two strings into @needle and @haystack. Then I iterate over the first of the two and count how many $differences there are, assuming a difference is the fact that the character at the very same position in the other string is not equal. If the $differences are exactly two, the task is succesful.