adjust program tests to new syntax, hello world works there too -)

lib/arm/logic_instruction.rb

@@ -30,7 +30,7 @@ module Arm
           @operand = op_with_rot
           @i = 1
         else
-          raise "cannot fit numeric literal argument in operand #{arg}"
+          raise "cannot fit numeric literal argument in operand #{arg.inspect}"
         end
       elsif (arg.is_a?(Symbol))
         @operand = arg

lib/vm/block.rb

@@ -65,6 +65,16 @@ module Vm
       @next = block
     end
 
+    # sugar to create instructions easily. Any method with one arg is sent to the machine and the result
+    # (hopefully an instruction) added as code
+    def method_missing(meth, *args, &block)
+      if args.length == 1
+        add_code Machine.instance.send(meth , *args)
+      else
+        super
+      end
+    end
+
   end
 
 end

lib/vm/program.rb

@@ -30,7 +30,7 @@ module Vm
       @functions = []
       @entry = Core::Kernel::main_start
       #main gets executed between entry and exit
-      @main = nil
+      @main = Block.new("main")
       @exit = Core::Kernel::main_exit
     end
     attr_reader :context , :main , :functions