rename register to risc

seems to fit the layer much better as we really have a very reduced
instruction set

lib/risc/instructions/slot_to_reg.rb

@@ -0,0 +1,25 @@
+module Risc
+
+  # SlotToReg moves data into a register from memory.
+  # RegToSlot moves data into memory from a register.
+  # Both use a base memory (a register)
+
+  # This is because that is what cpu's can do. In programming terms this would be accessing
+  #  an element in an array, in the case of SlotToReg setting the value in the array.
+
+  # btw: to move data between registers, use RiscTransfer
+
+  class SlotToReg < Getter
+
+  end
+
+  # Produce a SlotToReg instruction.
+  # Array and to are registers or symbols that can be transformed to a register by resolve_to_register
+  # index resolves with resolve_to_index.
+  def self.slot_to_reg source , array , index , to
+    index = resolve_to_index( array , index)
+    array = resolve_to_register( array )
+    to = resolve_to_register( to )
+    SlotToReg.new( source , array , index , to)
+  end
+end