checking return type is a type

lib/phisol/compiler/call_site.rb

@@ -56,7 +56,7 @@ module Phisol
           raise "unimplemented: \n#{code} \nfor #{ref.inspect}"
         end
       else
-        if( me.type == :int)
+        if( me.type.is_a? Phisol::Integer)
           name = :plus if name == :+
           method = Virtual.machine.space.get_class_by_name(:Integer).get_instance_method(name)
           puts Virtual.machine.space.get_class_by_name(:Integer).method_names.to_a

lib/phisol/compiler/function_definition.rb

@@ -40,13 +40,10 @@ module Phisol
       @method.source.receiver = r
       puts "compile method #{@method.name}"
 
-
-      #frame = frame.new_frame
       kids.to_a.each do |ex|
-        return_type = process(ex)
-        raise return_type.inspect if return_type.is_a? Virtual::Instruction
+        ret = process(ex)
+        raise ret.inspect if ret.is_a? Virtual::Instruction
       end
-      @method.source.return_type = return_type
       @method = nil
       Virtual::Return.new(return_type)
     end

lib/register/builtin/integer.rb

@@ -5,7 +5,7 @@ module Register
       module ClassMethods
         def plus c
           plus_function = Virtual::MethodSource.create_method(:Integer,:int,:plus , [:int] )
-          plus_function.source.return_type = Phisol::Type.int
+          plus_function.source.set_return_type Phisol::Type.int
           plus_function.source.receiver = Phisol::Integer
 
           tmp = Register.tmp_reg :int
@@ -44,7 +44,7 @@ module Register
 
         def putint context
           putint_function = Virtual::MethodSource.create_method(:Integer,:int,:putint , [] )
-          putint_function.source.return_type = Phisol::Type.int
+          putint_function.source.set_return_type Phisol::Type.int
           putint_function.source.receiver = Phisol::Integer
           return putint_function
           # buffer = Parfait::Word.new("           ") # create a buffer
@@ -73,7 +73,7 @@ module Register
         # not my hand off course, found in the net http://www.peter-cockerell.net/aalp/html/ch-5.html
         def fibo context
           fibo_function = Virtual::MethodSource.create_method(:Integer,:int,:fibo ,  [] )
-          fibo_function.source.return_type = Phisol::Type.int
+          fibo_function.source.set_return_type Phisol::Type.int
           fibo_function.source.receiver = Phisol::Integer
           return fibo_function
           # result = fibo_function.return_type

lib/register/builtin/kernel.rb

@@ -7,7 +7,7 @@ module Register
         # so it is responsible for initial setup
         def __init__ context
           function = Virtual::MethodSource.create_method(:Kernel,:int,:__init__ , [])
-          function.source.return_type = Phisol::Type.int
+          function.source.set_return_type Phisol::Type.int
           # no method enter or return (automatically added), remove
           function.source.blocks.first.codes.pop # no Method enter
           function.source.blocks.last.codes.pop # no Method return
@@ -26,7 +26,7 @@ module Register
         end
         def exit context
           function = Virtual::MethodSource.create_method(:Kernel,:int,:exit , [])
-          function.source.return_type = Phisol::Type.int
+          function.source.set_return_type  Phisol::Type.int
           return function
           ret = Virtual::RegisterMachine.instance.exit(function)
           function.set_return ret
@@ -34,7 +34,7 @@ module Register
         end
         def __send context
           function = Virtual::MethodSource.create_method(:Kernel,:int ,:__send , [] )
-          function.source.return_type = Phisol::Type.int
+          function.source.set_return_type Phisol::Type.int
           return function
         end
 

lib/virtual/method_source.rb

@@ -58,15 +58,20 @@ module Virtual
     def init method , return_type = nil
       # first block we have to create with .new , as new_block assumes a current
       enter = Block.new( "enter"  , method ).add_code(MethodEnter.new( method ))
-      @return_type = return_type if return_type
+      set_return_type( return_type )
       @blocks = [enter]
       @current = enter
       new_block("return").add_code(MethodReturn.new(method))
       @constants = []
     end
-    attr_reader   :blocks , :constants
-    attr_accessor :return_type , :current , :receiver
+    attr_reader   :blocks , :constants , :return_type
+    attr_accessor  :current , :receiver
 
+    def set_return_type type
+      return if type.nil?
+      raise "not type #{type}" unless type.is_a? Phisol::Type
+      @return_type = type
+    end
     # add an instruction after the current (insertion point)
     # the added instruction will become the new insertion point
     def add_code instruction