Fix bug with iteration of empty character class

It appears that it expects a Fixes [Rakudo Issue #1622](rakudo/rakudo#1622)
jstuder-gh · Mar 23, 2018 · 820c214 · 820c214
1 parent b5f9716
commit 820c214
Showing 1 changed file with 2 additions and 2 deletions.
diff --git a/src/QRegex/P6Regex/Actions.nqp b/src/QRegex/P6Regex/Actions.nqp
@@ -765,8 +765,8 @@ class QRegex::P6Regex::Actions is HLL::Actions {
             @alts.push(QAST::Regex.new( $str, :rxtype<enumcharlist>, :node($/), :negate( $<sign> eq '-' ),
                                         :subtype($RXm ?? 'ignoremark' !! '') ))
                 if nqp::chars($str);
-            $qast := +@alts == 1 ?? @alts[0] !!
-                $<sign> eq '-' ??
+            $qast := ( my $num := +@alts ) == 1 ?? @alts[0] !!
+                0 < $num && $<sign> eq '-' ??
                     QAST::Regex.new( :rxtype<concat>, :node($/), :negate(1),
                         QAST::Regex.new( :rxtype<conj>, :subtype<zerowidth>, |@alts ),
                         QAST::Regex.new( :rxtype<cclass>, :name<.> ) ) !!