AoC 2022, day 7

my %dirs;
my @cwd;

grammar FileTree {
    rule TOP { <command> || <dir-item> || <file-item> }

    rule command     { '$' [ 'ls' || <cd-command> ] }
    rule cd-command  { 'cd' <node-name> }

    rule dir-item  { 'dir' <node-name> }
    rule file-item { <file-size> <node-name> }

    token node-name { '/' || '..' || <[a..z] + [\.]>+ }
    token file-size { \d+ }
}

class FTactions {
    method cd-command($/) {
        given $<node-name>.made {
            when '/'  { @cwd = ''     }
            when '..' { @cwd.pop      }
            default   { @cwd.push($_) }
        }
    }
    method file-item($/) {
        for [\~] @cwd.map({ "$_/" }) -> \dir {
            %dirs{dir} += $<file-size>.made;
        }
    }
    method node-name($/) { make $/.Str }
    method file-size($/) { make $/.Int }
}

FileTree.parse($_, :actions(FTactions)) for $*IN.lines;
put 'part 1: ', %dirs.values.grep(* ≤ 10_0000).sum;
put 'part 2: ', %dirs.values.sort.first(* ≥ %dirs</> - 4000_0000);