gistfile1.txt

use v6;
my $css = q:to/END/;
<!--
pre { white-space: pre-wrap; font-family: monospace; color: #000000; background-color: #ffffff; }
body { font-family: monospace; color: #000000; background-color: #ffffff; }
* { font-size: 1em; }
.Constant { color: #0000c0; text-decoration: underline; }
.Comment { color: #c00000; font-weight: bold; }
.Special { color: #c000c0; font-weight: bold; }
.Identifier { color: #804000; text-decoration: underline; }
.Statement { color: #008080; font-weight: bold; }
.PreProc { color: #c000c0; text-decoration: underline; }
.Type { color: #008000; text-decoration: underline; }
-->
END

grammar KeyValuePairs {
    token TOP {
        [<pair> \n+]*
    }
    token ws { \h* }

    rule pair {
        \.<c=.c> '{' <rules=.rules> '}'
    }
    token c { \w+ }
    token rules { <-[}]>+ }
}

class KeyValuePairsActions {
    method c         ($/) { $/.make: ~$/                          }
    method rules     ($/) { $/.make: ~$/                          }
    method pair      ($/) { $/.make: $<c>.made => $<rules>.made }
    method TOP       ($/) { $/.make: $<pair>».made                }
}

my $res = KeyValuePairs.parse($css, :actions(KeyValuePairsActions)).made;
for @$res -> $p {
    say $p
    # say "Key: $p.c()\tValue: $p.rules()";
}