adds basic math operators, thanks to kasper associative and prioritised

lib/parser/expression.rb

@@ -14,5 +14,9 @@ module Parser
     rule(:expressions_else)   { delimited_expressions(keyword_else) }
     rule(:expressions_end)    { delimited_expressions(keyword_end) }
 
+    rule(:operator_expression) do
+       infix_expression(expression,  [multiply, 2, :left],  [plus, 1, :right]) 
+     end
+
   end
 end

lib/parser/tokens.rb

@@ -12,7 +12,10 @@ module Parser
     rule(:comma)  { str(',') >> space? }
     rule(:colon)  { str(':') >> space? }
     rule(:semicolon)  { str(';') >> space? }
-    rule(:question_mark)  { str('?') >> space? }    
-    rule(:excamation_mark)  { str('!') >> space? }    
+    rule(:question_mark)  { str('?') >> space? }
+    rule(:excamation_mark)  { str('!') >> space? }  
+
+    rule(:multiply) { match['*/']  >> space? }
+    rule(:plus) { match['+-']  >> space? }
   end
 end

lib/parser/transform.rb

@@ -41,6 +41,11 @@ module Parser
     rule(:asignee => simple(:left) , :asigned => simple(:right) ) do
       Ast::AssignmentExpression.new(left , right ) 
     end
+    
+    rule(l: simple(:l), o: simple(:o) , r: simple(:r)) do 
+      Ast::OperatorExpression.new( o.to_s.strip , l ,r)
+    end
+    
     #shortcut to get the ast tree for a given string
     # optional second arguement specifies a rule that will be parsed (mainly for testing)     
     def self.ast string , rule = :root