Accept extra commas in cron notation, gh-77

lib/fugit/cron.rb

@@ -660,7 +660,8 @@ module Parser include Raabro
       def s(i); rex(nil, i, /[ \t]+/); end
       def star(i); str(nil, i, '*'); end
       def hyphen(i); str(nil, i, '-'); end
-      def comma(i); str(nil, i, ','); end
+      def comma(i); rex(nil, i, /,([ \t]*,)*/); end
+      def comma?(i); rex(nil, i, /([ \t]*,)*/); end
 
       def slash(i); rex(:slash, i, /\/\d\d?/); end
 
@@ -720,12 +721,12 @@ def list_dom(i); jseq(:dom, i, :dom_elt, :comma); end
       def list_mon(i); jseq(:mon, i, :mon_elt, :comma); end
       def list_dow(i); jseq(:dow, i, :dow_elt_, :comma); end
 
-      def lsec_(i); seq(nil, i, :list_sec, :s); end
-      def lmin_(i); seq(nil, i, :list_min, :s); end
-      def lhou_(i); seq(nil, i, :list_hou, :s); end
-      def ldom_(i); seq(nil, i, :list_dom, :s); end
-      def lmon_(i); seq(nil, i, :list_mon, :s); end
-      alias ldow list_dow
+      def lsec_(i); seq(nil, i, :comma, '?', :list_sec, :comma, '?', :s); end
+      def lmin_(i); seq(nil, i, :comma, '?', :list_min, :comma, '?', :s); end
+      def lhou_(i); seq(nil, i, :comma, '?', :list_hou, :comma, '?', :s); end
+      def ldom_(i); seq(nil, i, :comma, '?', :list_dom, :comma, '?', :s); end
+      def lmon_(i); seq(nil, i, :comma, '?', :list_mon, :comma, '?', :s); end
+      def ldow(i); seq(nil, i, :comma, '?', :list_dow, :comma, '?'); end
 
       def _tz_name(i)
         rex(nil, i, / +[A-Z][a-zA-Z0-9+\-]+(\/[A-Z][a-zA-Z0-9+\-_]+){0,2}/)

spec/cron_spec.rb

@@ -1158,6 +1158,12 @@ class Fugit::Cron::TimeCursor
           #
           # some cronds are different, see https://crontab.guru/#7_0/1_*_*_*
 
+        [ '9,,19 * * * *', '9,19 * * * *' ],
+        [ ',8 * * * *', '8 * * * *' ],
+        [ ',,10,,20, * * * *', '10,20 * * * *' ],
+        [ '10,,20 * 1,,11,,21, * *', '10,20 * 1,11,21 * *' ],
+        [ ',,10,,22, * * * * Asia/Omsk', '10,22 * * * * Asia/Omsk' ],
+
       ].each { |c, e|
 
         it "parses #{c}" do