rubyx/lib/soml/compiler/field_access.rb

module Soml
  Compiler.class_eval do

    def on_field_access statement
      #puts statement.inspect
      receiver_ast , field_ast = *statement
      receiver = receiver_ast.first_from(:name)
      field_name = field_ast.first_from(:name)

      case receiver
      when :self
        index = @clazz.object_layout.variable_index(field_name)
        raise "field access, but no such field:#{field_name} for class #{@clazz.name}" unless index
        value = use_reg(@clazz.name) #TODO incorrect, this is the self, but should be the type of variable at index
        add_code Register.get_slot(statement , :message , :receiver , value )
        # reuse the register for next move
        move = Register.get_slot(statement, value , index , value )
        add_code move
      when :message
        #message Slot
        value = Register.message_reg
      else
        if( index = @method.has_arg(receiver)) #argument
          value = use_reg @method.arguments[index].type
          code = Register.get_slot(statement , :message , Parfait::Message.get_indexed(index), value)
        else # or a local so it is in the frame
          index = @method.has_local( receiver )
          if(index)
            value = use_reg @method.locals[index].type
            frame = use_reg :Frame
            add_code Register.get_slot(statement , :message , :frame , frame )
            code = Register.get_slot(statement ,frame , Parfait::Frame.get_indexed(index) , value )
          else
            raise "Variable not defined #{receiver}"
          end
        end
      end

      value
    end
  end
end