make condition brackets optional

lib/parser/control.rb

@@ -2,8 +2,10 @@ module Parser
   module Control
     include Parslet
     rule(:conditional) do
-      keyword_if >> left_parenthesis >> (simple_expression|operator_expression).as(:conditional) >> right_parenthesis >> newline >>
-        expressions_else.as(:if_true) >> newline >> expressions_end.as(:if_false)
+      keyword_if >> 
+      (( (simple_expression|operator_expression).as(:conditional) ) |
+        left_parenthesis >> (simple_expression|operator_expression).as(:conditional) >>  right_parenthesis) >>
+      newline >> expressions_else.as(:if_true) >> newline >> expressions_end.as(:if_false)
       end
     
     rule(:while_do) do

test/parser/test_conditional.rb

@@ -4,15 +4,22 @@ class TestConditional < MiniTest::Test
   # include the magic (setup and parse -> test method translation), see there
   include ParserHelper
   
-  def test_conditional
-    @string_input = <<HERE
-if(0) 
+  def test_conditional_brackets
+    check("(0)")
+  end
+  def test_conditional_no_brackets
+    check("0")
+  end
+    
+  def check cond
+    input = <<HERE
+
   42
 else
   667
 end
 HERE
-@string_input.chop!
+    @string_input = "if #{cond} " + input.chop!
     @parse_output = {:if=>"if", :conditional=>{:integer=>"0"}, 
     :if_true=>{:expressions=>[{:integer=>"42"}], :else=>"else"}, 
     :if_false=>{:expressions=>[{:integer=>"667"}], :end=>"end"}}