recurring bug, don't save label positions

labels are ethereal, no length, so they don’t get to occupy a position

lib/risc/position.rb

@@ -65,9 +65,11 @@ module Risc
         if testing.class != position.class
           raise "Mismatch (at #{to.to_s(16)}) new:#{position}:#{position.class} , was #{testing}:#{testing.class}"
         end
-        @reverse_cache.delete(to)
       end
+      unless position.object.is_a? Label
+        @reverse_cache.delete(to)
         @reverse_cache[position.at] = position
+      end
       log.debug "Reset #{position} (#{to.to_s(16)}) for #{position.class}"
       return position
     end
@@ -81,7 +83,7 @@ module Risc
       raise "Mismatch (at #{pos.to_s(16)}) was:#{position} #{position.class} #{position.object} , should #{testing}#{testing.class}" if testing and testing.class != position.class
       self.positions[object] = position
       position.init(pos)
-      @reverse_cache[position.at] = position
+      @reverse_cache[position.at] = position unless object.is_a? Label
       log.debug "Set #{position} (#{pos.to_s(16)}) for #{position.class}"
       position
     end

test/risc/position/test_instruction_position.rb

@@ -35,6 +35,14 @@ module Risc
         assert_equal InstructionPosition , at_4.class
         assert_equal Branch , at_4.instruction.class
       end
+      def test_label_at_reverse
+        branch = Branch.new("b" , @label)
+        Position.set(branch , 8 , @binary)
+        Position.set(@label , 8 , @binary)
+        at_4 = Position.at(8)
+        assert_equal InstructionPosition , at_4.class
+        assert_equal Branch , at_4.instruction.class
+      end
       def test_reset_false_type
         assert_raises {Position.set(@label , 0 , @binary)}
       end

test/risc/test_interpreter.rb

@@ -3,16 +3,16 @@ require_relative "helper"
 module Risc
   class TestInterpreterBasics < MiniTest::Test
 
-    def pest_class
+    def test_class
       assert_equal Risc::Interpreter , Interpreter.new.class
     end
-    def pest_starts_stopped
+    def test_starts_stopped
       assert_equal :stopped , Interpreter.new.state
     end
-    def pest_has_regs
+    def test_has_regs
       assert_equal 12 , Interpreter.new.registers.length
     end
-    def pest_has_r0
+    def test_has_r0
       assert_equal :r0 , Interpreter.new.registers.keys.first
     end
   end
@@ -23,14 +23,14 @@ module Risc
       @machine.position_all
       @interpreter = Interpreter.new
     end
-    def pest_starts
+    def test_starts
       assert_equal 0 , @interpreter.start_machine
     end
-    def pest_started
+    def test_started
       @interpreter.start_machine
       assert_equal :running , @interpreter.state
     end
-    def pest_pos
+    def test_pos
       @interpreter.start_machine
       assert_equal 1 , @interpreter.clock
     end
@@ -43,30 +43,30 @@ module Risc
       @interpreter = Interpreter.new
       @interpreter.start_machine
     end
-    def pest_tick1
+    def test_tick1
       assert_equal 2 , @interpreter.tick
     end
-    def pest_clock1
+    def test_clock1
       @interpreter.tick
       assert_equal 2 , @interpreter.clock
     end
-    def pest_pc1
+    def test_pc1
       @interpreter.tick
-      assert_equal 19484 , @interpreter.pc
+      assert_equal 18392 , @interpreter.pc
     end
-    def pest_tick2
+    def test_tick2
       @interpreter.tick
       assert_equal 3 , @interpreter.tick
     end
-    def pest_clock2
+    def test_clock2
       @interpreter.tick
       @interpreter.tick
       assert_equal 3 , @interpreter.clock
     end
-    def pest_pc2
+    def test_pc2
       @interpreter.tick
       @interpreter.tick
-      assert_equal 19488 , @interpreter.pc
+      assert_equal 18396 , @interpreter.pc
     end
     def test_tick_15
       15.times {@interpreter.tick}