Change Mom to SlotMachine

rather large commit, but essentially a simple rename
Rationale in docs and blogs

lib/slot_machine/macro/macro.rb

@@ -0,0 +1,67 @@
+module Mom
+  class Macro < Instruction
+
+    def to_s
+      self.class.name.split("::").last
+    end
+
+    # emit the syscall with given name
+    # there is a Syscall instruction, but the message has to be saved and restored
+    def self.emit_syscall( builder , name )
+      save_message( builder )
+      builder.add_code Risc::Syscall.new("emit_syscall(#{name})", name )
+      restore_message(builder)
+      return unless (@clazz and @method)
+      builder.add_code Risc.label( "#{@clazz.name}.#{@message.name}" , "return_syscall" )
+    end
+
+    # a sort of inline version of exit method.
+    # Used by exit and __init__ (so it doesn't have to call it)
+    # Assumes int return value and extracts the fixnum for process exit code
+    def self.exit_sequence(builder)
+      save_message( builder )
+      builder.build do
+        message << message[:return_value]
+        message.reduce_int
+        add_code Risc::Syscall.new("emit_syscall(exit)", :exit )
+      end
+    end
+
+    # save the current message, as the syscall destroys all context
+    #
+    # This relies on linux to save and restore all registers
+    #
+    def self.save_message(builder)
+      r8 = Risc::RegisterValue.new( :r8 , :Message).set_builder(builder)
+      builder.build {r8 << message}
+    end
+
+    # restore the message that we save in r8
+    # before th restore, the syscall return, a fixnum, is saved
+    # The caller of this method is assumed to caal prepare_int_return
+    # so that the return value already has an integer instance
+    # This instance is filled with os return value
+    def self.restore_message(builder)
+      r8 = Risc::RegisterValue.new( :r8 , :Message)
+      builder.build do
+        integer_reg! << message
+        message << r8
+        integer_2! << message[:return_value]
+        integer_2[Parfait::Integer.integer_index] << integer_reg
+      end
+    end
+  end
+end
+
+require_relative "comparison"
+require_relative  "exit"
+require_relative "init"
+require_relative	"putstring"
+require_relative "set_internal_word"
+require_relative "div10"
+require_relative "get_internal_byte"
+require_relative "method_missing"
+require_relative "div4"
+require_relative "get_internal_word"
+require_relative "operator"
+require_relative "set_internal_byte"