foo

#!/usr/bin/env perl6

sub sprint( Match:D $m, $nm='TOP', $indent is copy = 0) {
   sub i { ' ' x ($indent * 2) }
   sub show(Str $s) {  $s.substr(0, 30).perl; }

   my $s = '';
   $s = i() ~ "$m.from() $m.to() $nm  " ~ show( ~$m)  ~ "\n";
#   for $m.caps {
        $s ~= sprint $_.value, $_.key, $indent + 1 if $_.value ~~ Match for $m.caps;
#   }
   $s;
}

"foo bar baz" ~~ m:s/ (\w+) ((\w)+) (\w+) /;
say sprint($/);

output

➤ ./perl6 foo
0 11 TOP  "foo bar baz"
  0 3 0  "foo"
  4 7 1  "bar"
    4 5 0  "b"
    5 6 0  "a"
    6 7 0  "r"
  8 11 2  "baz"

patch

diff --git a/src/Perl6/Actions.pm b/src/Perl6/Actions.pm
index 2ea20e9..5a93bd7 100644
--- a/src/Perl6/Actions.pm
+++ b/src/Perl6/Actions.pm
@@ -552,7 +552,7 @@ class Perl6::Actions is HLL::Actions {
                         PAST::Op.new(
                             :pasttype<callmethod>, :name<map>, :node($/),
                             PAST::Op.new(:name('&infix:<,>'), $cond),
-                            $past
+                            block_closure($past)
                         ));
                 }
                 else {