a good stab at array anf hash constants

lib/parser/transform.rb

@@ -10,6 +10,12 @@ module Parser
     rule(:integer => simple(:value)) { Ast::IntegerExpression.new(value.to_i) }
     rule(:name   => simple(:name))  { Ast::NameExpression.new(name.to_s) }
 
+    rule(:array => sequence(:array) ) { Ast::ArrayExpression.new(array) } 
+    rule(:element  => simple(:element))    { element  }
+    rule(:hash => sequence(:hash) ) { Ast::HashExpression.new(hash) } 
+    rule(:argument => simple(:argument) , :element => simple(:element)) {  Ast::AssociationExpression.new(argument,element) }
+    rule(:hash_pair => simple(:hash_pair) ) {  hash_pair }
+
     rule(:argument  => simple(:argument))    { argument  }
     rule(:argument_list => sequence(:argument_list)) { argument_list }