Any function supports dereferencing now. Also traits

examples/traits.ns

@@ -1,10 +1,12 @@
 Runnable = trait({
   run: -> speed
-    print('running with traits at speed:', speed)
+    print(@name, 'is running with traits at speed:', speed)
   end
 })
 
 person = Object.clone()
 person.uses(Runnable)
 
+person.name = 'John'
+
 person.run(10)

lib/noscript/ast.rb

@@ -27,9 +27,13 @@ def compile(context)
       end
     end
 
-    class Identifier < Struct.new(:name)
+    class Identifier < Struct.new(:name, :deref)
       def compile(context)
-        context.lookup_var(name)
+        if deref
+          context.current_receiver.slots[name]
+        else
+          context.lookup_var(name)
+        end
       end
       def to_s
         name
@@ -76,17 +80,24 @@ def compile(context)
 
     class Message < Struct.new(:receiver, :slot)
       def compile(context)
+        ctx = Context.new(context)
+        ctx.current_receiver = context.current_receiver
+
         if receiver
           # rcv.foo() looks up the message in the receiver slots
           rcv = receiver.compile(context)
+
+          # Save a reference to the current receiver
+          ctx.current_receiver = rcv
+
           retval = rcv.send(name)
         else
           # foo() looks up a function in the global context
           retval = context.lookup_var(name)
         end
 
         if call?
-          retval.call(context, *arguments)
+          retval.call(ctx, *arguments)
         else
           retval
         end

lib/noscript/context.rb

@@ -17,12 +17,11 @@ def self.generate
       ctx
     end
 
-    attr_accessor :lvars, :methods
+    attr_accessor :lvars, :current_receiver
 
     def initialize(parent_context = nil)
       @parent = parent_context
       @lvars = {}
-      @methods = {}
     end
 
     def lookup_var(symbol)

lib/noscript/method.rb

@@ -4,6 +4,8 @@ def call(context, *args)
       raise_argument_error(args) if args.size > params.size
 
       ctx = Context.new(context)
+      ctx.current_receiver = context.current_receiver
+
       params.each_with_index do |param, idx|
         if passed_value = args[idx]
           ctx.store_var(param.name, passed_value.compile(ctx))

lib/noscript/parser/noscript.racc

@@ -29,6 +29,7 @@ rule
   while   : WHILE expression end_of_statement statements END { result = AST::WhileNode.new(val[1], val[3]) }
 
   identifier : IDENTIFIER { result = AST::Identifier.new(val[0]) }
+             | DEREF { result = AST::Identifier.new(val[0], true)}
 
   digit : DIGIT { result = AST::Digit.new(val[0]) }
   string : STRING { result = AST::String.new(val[0]) }

lib/noscript/parser/noscript.rex

@@ -34,6 +34,7 @@ rule
   else          { [:ELSE, text] }
   while         { [:WHILE, text] }
 
+  @\w[{BLANK}\w]* { [:DEREF, text.strip[1..-1]] }
   \w[{BLANK}\w]* { [:IDENTIFIER, text.strip] }
 
   \s

lib/noscript/parser/noscript.rex.rb

@@ -129,6 +129,9 @@ def _next_token
       when (text = @ss.scan(/while/))
          action { [:WHILE, text] }
 
+      when (text = @ss.scan(/@\w[[ ]\w]*/))
+         action { [:DEREF, text.strip[1..-1]] }
+
       when (text = @ss.scan(/\w[[ ]\w]*/))
          action { [:IDENTIFIER, text.strip] }
 

test/context_test.rb

@@ -5,7 +5,6 @@ class ContextTest < MiniTest::Unit::TestCase
   def setup
     @context = Noscript::Context.new
     @context.lvars   = { 'foo' => 3 }
-    @context.methods = { 'lorem' => proc { 'ipsum' } }
   end
 
   # Local variable lookup and storage

test/integration_test.rb

@@ -34,7 +34,8 @@ def test_traits
     output = `./bin/noscript examples/traits.ns`.split("\n")
 
     assert_equal [
-      "running with traits at speed:",
+      "John",
+      "is running with traits at speed:",
       "10"
     ], output
   end

test/lexer/lexer_test.rb

@@ -95,4 +95,8 @@ def test_fun
     tokenizes "->", [[:FUN, '->']]
   end
 
+  def test_deref
+    tokenizes "@name", [[:DEREF, 'name']]
+  end
+
 end

test/method_test.rb

@@ -104,4 +104,21 @@ def test_method_with_too_many_arguments
     end
   end
 
+  def test_method_with_dereferencing
+    # -> bar=23
+    #   a = 3
+    #   74
+    #   @foo
+    # end
+    @method.body.nodes.push(
+      Noscript::AST::Identifier.new('foo', true)
+    )
+    object = Noscript::Object.new
+    object.add_slot('foo', Noscript::AST::Digit.new(123))
+
+    @context.current_receiver = object
+
+    assert_equal Noscript::AST::Digit.new(123), @method.call(@context)
+  end
+
 end