fmt p6

#!/usr/bin/env perl6

use v6;

grammar Fmt { 
    token TOP { ^[<para>+||<literal>+||<wordspace>+]+ <theend> }
    #token wordspace { [<:Cc>*||\w+][\h+||\n] }
    token wordspace { \S+[\h+||\n] }
    token para { ^^\h*\n }
    token literal { ^^\h+\N+\n }
    token theend { $ }
}

class FmtAction {
        has Str $.buf = "";
        has Int $!max = 80;
        method wordspace($/) {
                my $x = $/.make(~$/);
                $x.=subst(/\n/, ' ');
                if $x.chars + $!buf.chars < $!max {
                        $!buf ~= $x;
                } else {
                        say "$!buf";
                        $!buf = $x;
                }
        }
        method literal($/) {
                say "$!buf" if $!buf.chars > 0;
                $!buf = "";
                print $/.make(~$/);
        }
        method para($/) {
                say "$!buf" if $!buf.chars > 0;
                $!buf = "";
                print $/.make(~$/);
        }
        method theend($/) {
                say "$!buf";
                $!buf = "";
        }
}

my $a = FmtAction.new;
my $doc = $*IN.slurp-rest;
my $n = Fmt.parse($doc, :actions($a));