make ints compile time mutable

to change the label value and use the allocated stubs

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)