lib/ebnf/ll1.rb in ebnf-1.0.1 vs lib/ebnf/ll1.rb in ebnf-1.0.2

@@ -283,11 +283,11 @@
 
       if rule.alt?
         # A First/Follow conflict appears when _eps is in the first
         # of one rule and there is a token in the first and
         # follow of the same rule
-        if rule.first.include?(:_eps) && !(overlap = ((rule.first & rule.follow) - [:eps])).empty?
+        if rule.first.include?(:_eps) && !(overlap = ((rule.first & (rule.follow || [])) - [:eps])).empty?
           error("First/Follow Conflict: #{overlap.first.inspect} is both first and follow of #{rule.sym}")
         end
 
         # Add entries for each alternative, based on the alternative's first/seq
         rule.expr[1..-1].each do |prod|
@@ -304,10 +304,11 @@
           else
             prod_rule.first.reject{|f| f == :_eps}.each do |f|
               # A First/First conflict appears when there are two rules having
               # the same first, so the parser can't know which one to choose.
               if branchDict.has_key?(f)
-                error("First/First Conflict: #{f.inspect} is also the condition for #{branchDict[f].first}")
+                #require 'byebug'; byebug
+                error("First/First Conflict: #{f.inspect} is the condition for both #{prod_rule.sym} and #{branchDict[f].first}")
               end
 
               debug("   alt") {"[#{f}] => #{prod}"}
               branchDict[f] = [prod]
             end