make method creation class methods in MethodCompiler

and pass the wish to use main explicitly, which is really a test
feature

lib/vm/method_compiler.rb

@@ -56,7 +56,7 @@ module Vm
   # Helper function to create a new compiler and compie the statement(s)
   # Statement must be and AST::Node as generated by s expressions
   def self.compile_ast( statement )
-    compiler = MethodCompiler.new
+    compiler = MethodCompiler.new(:main)
     code = Vm.ast_to_code statement
     compiler.process code
   end
@@ -66,15 +66,15 @@ module Vm
       include Vm.const_get( mod.camelize )
     end
 
-    def initialize( method = nil )
+    def initialize( method )
       @regs = []
-      if method
-        @method = method
-        @type = method.for_type
-      else
+      if method == :main
         @type = Parfait.object_space.get_type()
         @method = @type.get_method( :main )
         @method = @type.create_method( :main ,{}) unless @method
+      else
+        @method = method
+        @type = method.for_type
       end
       @current = @method.instructions
     end
@@ -107,7 +107,7 @@ module Vm
 
     # create the method, do some checks and set it as the current method to be added to
     # class_name and method_name are pretty clear, args are given as a ruby array
-    def create_method( class_name , method_name , args = {})
+    def self.create_method( class_name , method_name , args = {})
       raise "create_method #{class_name}.#{class_name.class}" unless class_name.is_a? Symbol
       clazz = Parfait.object_space.get_class_by_name! class_name
       create_method_for( clazz.instance_type , method_name , args)
@@ -118,13 +118,12 @@ module Vm
     # args a hash that will be converted to a type
     # the created method is set as the current and the given type too
     # return the compiler (for chaining)
-    def create_method_for( type , method_name , args )
-      @type = type
+    def self.create_method_for( type , method_name , args )
       raise "create_method #{type.inspect} is not a Type" unless type.is_a? Parfait::Type
       raise "Args must be Hash #{args}" unless args.is_a?(Hash)
       raise "create_method #{method_name}.#{method_name.class}" unless method_name.is_a? Symbol
-      @method = type.create_method( method_name , args)
-      self
+      method = type.create_method( method_name , args)
+      self.new(method)
     end
 
     # add method entry and exit code. Mainly save_return for the enter and