[GGE::Match] updated dump_str

It's now more in line with PGE's dump_str output. Need to make it recurse
when showing captures, but no need to do that before actually implementing
the captures.

Also added vertical whitespace here and there in the debug output so that
things group better visually.

lib/GGE/Match.pm

@@ -38,10 +38,18 @@ class GGE::Match {
         return $!to >= $!from;
     }
 
-    method dump_str() {
-        ?self.true()
-            ?? sprintf '<%s @ 0>', $!target.substr($!from, $!to - $!from)
-            !! '';
+    method dump_str($prefix?, $b1 = '[', $b2 = ']') {
+        my $out = sprintf "%s: <%s @ %d> \n",
+                          $prefix,
+                                $!target.substr($!from, $!to - $!from),
+                                     $!from;
+        if self.llist {
+            for self.llist.kv -> $index, $elem {
+                $out ~= [~] $prefix, $b1, $index, $b2;
+                $out ~= ': ', '...', "\n";
+            }
+        }
+        $out
     }
 
     method Str() {

lib/GGE/Perl6Regex.pm

@@ -138,6 +138,7 @@ class GGE::Perl6Regex {
     method postcircumfix:<( )>($target, :$debug) {
         if $debug {
             say $!regex.structure;
+            say '';
         }
         GGE::TreeSpider.new(:$!regex, :$target, :pos(*)).crawl(:$debug);
     }

t/perl6regex/01-regex.t

@@ -54,7 +54,8 @@ for @test-files -> $test-file {
         }
         else {
             $result .= substr(1,-1); # remove /'s
-            ok defined($match.dump_str.index($result)), $full-description;
+            ok defined($match.dump_str('mob', ' ', '').index($result)),
+               $full-description;
         }
     }
 }

test-regex

@@ -8,7 +8,9 @@ die "Usage: ./test-regex <pattern> <target>"
 my ($pattern, $target) = @*ARGS;
 my GGE::Match $match
     = GGE::Perl6Regex.new($pattern).(backslash_escape($target), :debug);
-say $match.dump_str() || 'No match';
+
+say '';
+say $match.dump_str('mob', ' ', '') || 'No match';
 
 sub backslash_escape($string) {
     return $string.trans(['\n', '\r', '\e', '\t', '\f'] =>