if and goto for slot_language

lib/slot_language/README.md

@@ -10,11 +10,11 @@ The Problem with the current way is that some of the slot_machine instruction ar
 really quite complex. They are really more function than instructions.
 
 This is especially true for everything around the dynamic call. Dynamic call itself
-is still or, but resolve_method is too much. And it even uses method_missing, another
+is still ok, but resolve_method is too much. And it even uses method_missing, another
 instruction that is too much, which in turn should use raise and now we really see
 the point.
 
-I though about making those "super" instruction real methods and just calling them,
+I thought about making those "super" instruction real methods and just calling them,
 but the calling overhead is just too much, and really it is the wrong tool for the
 job. Calling implies switching of context, while resolve_method and raise and mm
 really all operate on the same context.
@@ -23,7 +23,7 @@ really all operate on the same context.
 
 The Slot Machine is a kind of memory based, oo abstraction of the risc machine, that in
 turn mirrors a cpu relatively closely. The machine "knows" the message in the way a
-cpu knows it's registers. And the oo part means it also knows the parfait object
+cpu knows its registers. And the oo part means it also knows the parfait object
 model.
 
 While Ruby/Sol code only ever assumes the type of self, the Slot Machine assumes types
@@ -41,10 +41,15 @@ the message.
 
 ## Syntax (projection)
 
-Since we are not defining methods, etc, there is no scope. In other words the only
-"scope" is the current message and global constants. This also means we will
-use the file scope, ie one file defines one instruction, by convention of the
-same name.
+Since we are not defining methods, there is no seperate scope. We create objects that
+will transform to SlotMachine Instructions _in_ the scope of the current method.
+In other words they will have access to the compiler and the callable, when transforming
+to SlotMachine (similar to Sol in that way). This means at compile time we have
+can use the frame type and constants, while we can always assume the Message (and not
+much else) at runtime.
+
+As the scope is "fixed", we will use the file scope, ie one file defines one
+instruction/macro, by convention of the same name.
 
 For starters we will use ruby syntax, with these semantics:
 - only globals and message (the literal) are valid variable names

lib/slot_language/check_maker.rb

@@ -0,0 +1,14 @@
+module SlotLanguage
+  class CheckMaker
+    attr_reader :check , :left , :right, :goto
+
+    def initialize(check , left , right)
+      @check = check
+      @left = left
+      @right = right
+    end
+    def set_goto(go)
+      @goto = go
+    end
+  end
+end

lib/slot_language/slot_compiler.rb

@@ -16,19 +16,27 @@ module SlotLanguage
       not_implemented(node)
     end
     def on_send(statement)
-      #puts  statement
       kids = statement.children.dup
       receiver = process(kids.shift) || MessageSlot.new
       name = kids.shift
       return label(name) if(name.to_s.end_with?("_label"))
+      return goto(name,kids) if(name == :goto)
+      return check(name,receiver, kids) if(name == :==)
       SlotMaker.new( name , receiver )
     end
     def on_lvasgn expression
-      #puts expression
       name = expression.children[0]
       value = process(expression.children[1])
       Sol::LocalAssignment.new(name,value)
     end
+    def on_if(expression)
+      condition = process(expression.children[0])
+      condition.set_goto( process(expression.children[1]) )
+      condition
+    end
+    def on_begin(exp)
+      process(exp.first)
+    end
     def on_ivar expression
       Sol::InstanceVariable.new(instance_name(expression.children.first))
     end
@@ -40,8 +48,21 @@ module SlotLanguage
     def label(name)
       SlotMachine::Label.new(name.to_s , name)
     end
+    def goto(name , args)
+      # error handling would not hurt
+      label = process(args.first)
+      SlotMachine::Jump.new(  label )
+    end
+    def check(name , receiver , kids)
+      raise "Only ==, not #{name}" unless name == :==
+      raise "Familiy too large #{kids}" if kids.length > 1
+      puts  "Kids " + kids.to_s
+      right = process(kids.first)
+      CheckMaker.new(name , receiver , right)
+    end
   end
 end
 require_relative "named_slot"
 require_relative "message_slot"
 require_relative "slot_maker"
+require_relative "check_maker"

test/slot_language/helper.rb

@@ -6,7 +6,7 @@ module SlotLanguage
       SlotCompiler.compile(input)
     end
     def compile_class(input)
-      compile.class
+      compile(input).class
     end
   end
 end

test/slot_language/test_slot_compiler.rb

@@ -19,7 +19,15 @@ module SlotLanguage
       assert_equal :while_label , label.name
     end
     def test_slot_load
-      compile("a = @b")
+      assert_equal Sol::LocalAssignment , compile_class("a = @b")
+    end
+    def test_goto
+      assert_equal SlotMachine::Jump , compile_class("goto(exit_label)")
+    end
+    def test_if
+      check = compile("goto(exit_label) if(a == b)")
+      assert_equal CheckMaker , check.class
+      assert_equal SlotMachine::Jump , check.goto.class
     end
   end
 end