make ints compile time mutable

to change the label value and use the allocated stubs

lib/mom/instruction/label.rb

@@ -1,6 +1,6 @@
 module Mom
 
-  # A Label is the only legal target for a branch (this is true in Mom and Risc)
+  # A Label is the only legal target for a branch (in Mom, in Risc a BinaryCode is ok too)
   #
   # In the dynamic view (runtime) where the instructions form a graph,
   # branches fan out, Labels collect. In other words a branch is the place where
@@ -31,6 +31,7 @@ module Mom
     # Off course some specific place still has to be responsible for actually
     # adding the label to the instruction list (usually an if/while)
     def to_risc(compiler)
+      
       @risc_label ||= Risc::Label.new(self,name)
     end
   end

lib/parfait/integer.rb

@@ -27,6 +27,12 @@ module Parfait
       type_length
     end
 
+    # compile time method to set the actual value.
+    # this should not really be part of parfait, as ints are immutable at runtime.
+    def set_value(value)
+      set_internal_word(Integer.integer_index, value)
+    end
+
     # :integer?, :odd?, :even?, :upto, :downto, :times, :succ, :next, :pred, :chr, :ord, :to_i, :to_int, :floor,
     # :ceil, :truncate, :round, :gcd, :lcm, :gcdlcm, :numerator, :denominator, :to_r, :rationalize,
     # :singleton_method_added, :coerce, :i, :+@, :-@, :fdiv, :div, :divmod, :%, :modulo, :remainder, :abs, :magnitude,

lib/parfait/space.rb

@@ -52,6 +52,16 @@ module Parfait
     attr_reader  :classes , :types , :first_message , :next_integer
     attr_reader  :true_object , :false_object , :nil_object
 
+    # hand out one of the preallocated ints for use as constant
+    # the same code is hardcoded as risc instructions for "normal" use, to
+    # avoid the method call at runtime. But at compile time we want to keep
+    # the number of integers known (fixed).
+    def get_integer
+      int = @next_integer
+      @next_integer = @next_integer.next_integer
+      int
+    end
+
     def each_type
       @types.values.each do |type|
         yield(type)

test/parfait/test_integer.rb

@@ -43,6 +43,9 @@ module Parfait
         int = int.next_integer
       end
     end
-
+    def test_set
+      @int.set_value(1)
+      assert_equal 1 , @int.value
+    end
   end
 end

test/parfait/test_space.rb

@@ -33,6 +33,10 @@ module Parfait
       assert_equal 14, int.instance_type.method_names.get_length
     end
 
+    def test_get_integer_instance
+      int = @space.get_integer
+      assert_equal Integer , int.class
+    end
     def test_classes_class
       classes.each do |name|
         assert_equal :Class , @space.classes[name].get_class.name