implement put string and fix set

lib/interpreter.rb

@@ -7,9 +7,11 @@ class Interpreter
   attr_accessor :instruction
   attr_accessor :link
   attr_accessor :block
-  attr_accessor :registers
+  attr_reader :registers
+  attr_reader :stdout
 
   def initialize
+    @stdout = ""
     @registers = {}
     (0...12).each do |r|
       set_register "r#{r}".to_sym , "undefined"
@@ -32,7 +34,6 @@ class Interpreter
   def set_instruction i
     return if @instruction == i
     raise "Error, nil instruction" unless i
-    puts "next up #{i.class}"
     old = @instruction
     @instruction = i
     trigger(:instruction_changed, old , i)
@@ -70,8 +71,9 @@ class Interpreter
 
   def object_for reg
     id = get_register(reg)
-    object = Virtual.machine.objects[id]
+    Virtual.machine.objects[id]
   end
+
   # Instruction interpretation starts here
   def execute_Branch
     target = @instruction.block
@@ -95,8 +97,8 @@ class Interpreter
   end
 
   def execute_SetSlot
-    object = object_for( @instruction.register )
-    value = object_for( @instruction.array )
+    value = object_for( @instruction.register )
+    object = object_for( @instruction.array )
     object.internal_object_set( @instruction.index , value )
     true
   end
@@ -116,8 +118,21 @@ class Interpreter
 
   def execute_SaveReturn
     object = object_for @instruction.register
+    raise "save return has nothing to save" unless @link
     object.internal_object_set @instruction.index , @link
     true
   end
 
+  def execute_Syscall
+    name = @instruction.name
+    case name
+    when :putstring
+      str = object_for( :r1 ) # should test length, ie r2
+      raise "NO string for putstring #{str}" unless str.is_a? Symbol
+      @stdout += str.to_s
+    else
+      raise "un-implemented syscall #{name}"
+    end
+    true
+  end
 end

test/interpreter_test.rb

@@ -19,40 +19,51 @@ class InterpreterTest < MiniTest::Test
     end
     return last
   end
-  def test_first_branch
+  def test_branch
     was = @interpreter.block
     assert_equal Register::Branch , ticks(1).class
     assert was != @interpreter.block
   end
-  def test_second
+  def test_load
     assert_equal Register::LoadConstant ,  ticks(2).class
     assert_equal Parfait::Space ,  Virtual.machine.objects[ @interpreter.get_register(:r1)].class
     assert_equal :r1,  @interpreter.instruction.array.symbol
   end
-  def test_third
+  def test_get
     assert_equal Register::GetSlot , ticks(3).class
     assert @interpreter.get_register( :r3 )
     assert @interpreter.get_register( :r3 ).is_a? Integer
   end
-  def test_fourth
-    assert_equal Register::SetSlot ,  ticks(4).class
-  end
-  def test_fifth
+  def test_transfer
     transfer = ticks 5
     assert_equal Register::RegisterTransfer ,  transfer.class
     assert_equal @interpreter.get_register(transfer.to) , @interpreter.get_register(transfer.from)
   end
-  def test_sixth
-    assert_equal Register::GetSlot ,  ticks(6).class
-  end
-  def test_seventh
+  def test_call
     assert_equal Register::FunctionCall ,  ticks(7).class
+    assert @interpreter.link
   end
-  def test_eighth
-    assert_equal Register::SaveReturn ,  ticks(8).class
+  def test_save
+    done = ticks(8)
+    assert_equal Register::SaveReturn ,  done.class
+    assert @interpreter.get_register done.register.symbol
   end
-  def test_ninth
-    assert_equal Register::LoadConstant ,  ticks(9).class
+
+  def test_chain
+    ["Branch" , "LoadConstant" , "GetSlot" , "SetSlot" , "RegisterTransfer" ,
+     "GetSlot" , "FunctionCall" , "SaveReturn" , "LoadConstant"  , "SetSlot" ,
+     "GetSlot" ,  "GetSlot" , "SetSlot" , "LoadConstant" , "SetSlot" ,
+     "RegisterTransfer" ,  "GetSlot" ,  "FunctionCall" , "SaveReturn" ,
+     "RegisterTransfer" , "Syscall"].each_with_index do |name , index|
+      got = ticks(1)
+      assert got.class.name.index(name) , "Wrong class for #{index}, expect #{name} , got #{got}"
+    end
+  end
+
+  def test_putstring
+    done = ticks(21)
+    assert_equal Register::Syscall ,  done.class
+    assert_equal "Hello again" , @interpreter.stdout  
   end
 
 end