to-json.p6

use v6;
use Test;

sub to-json($arg) {
  given $arg.^name {
  when 'Bool' { $arg.Str.lc }
  when 'Int' { $arg.Str }
  when 'Rat' { $arg.Str }
  when 'Num' { $arg.Str }
  when 'Str' { $arg.Str.perl }
  when 'Array' { "[{{$arg.map(&to-json).join(',')}}]" }
  when 'Hash' { "\{{{$arg.map(&to-json).join(',')}}\}" }
  when 'Pair' { "{{to-json $arg.key}}:{{to-json $arg.value}}" }
  default { die "WHY JAPANESE PEOPLE!: {{$arg.^name}}" }
  }
}

Any.^add_method('to-json', method () { to-json self; });
.^compose for [Num,Int,Rat,Array,Str,Hash,Bool];

is [1, "foo"].to-json, '[1,"foo"]';
is 1.to-json, '1';
is 1.2.to-json, '1.2';
is True.to-json, 'true';
is False.to-json, 'false';
is { foo => "bar", {bar => 'baz'}}.to-json, '{"bar":"baz","foo":"bar"}';
is 1e9.to-json, 1000000000;