SlotLanguage reborn in the Machine

Just added the compiler, that can parse Slot directly into SlotMachine code (no language layer in between)
Still unclear wheather the Maker is a thing, but since it was in the Language layer i did not remove it (yet)
Otherwise just the compiler and all the tests, moved from the slot_language.

test/slot_machine/compiler/test_variable.rb

@@ -0,0 +1,38 @@
+require_relative "../helper"
+
+module SlotMachine
+  class TestVariable < MiniTest::Test
+    include SlotHelper
+    def compile_var(str)
+      var = compile(str)
+      assert var.is_a?(Slotted) , "Was #{var.class}"
+      var
+    end
+    def test_local
+      assert_equal SlottedMessage , compile_var("a").class
+    end
+    def test_inst
+      var = compile_var("@a")
+      assert_equal SlottedMessage , var.class
+    end
+    def test_local_chain
+      chain = compile_var("a.b")
+      assert_equal Slot , chain.slots.class
+      assert_equal :b , chain.slots.next_slot.name
+    end
+    def test_local_chain2
+      chain = compile_var("a.b.c")
+      assert_equal Slot , chain.slots.next_slot.next_slot.class
+      assert_equal :c , chain.slots.next_slot.next_slot.name
+    end
+    def test_inst_chain
+      chain = compile_var("@a.b")
+      assert_equal SlottedMessage , chain.class
+      assert_equal Slot , chain.slots.class
+      assert_equal :receiver , chain.slots.name
+      assert_equal Slot , chain.slots.class
+      assert_equal :a , chain.slots.next_slot.name
+      assert_equal :b , chain.slots.next_slot.next_slot.name
+    end
+  end
+end