+class g a :: a -> Gen SSMProgram
+
+instance g Expr where
+ g (VarExpr _ (VarDef k fs)) = pure <$> load k //note: pure is pure for list, i.e. []
+
+load :: String -> Gen Instr
+load k = genMap >>= \g-> case 'Map'.member k g of
+ False = liftT (Left $ Error $ concat ["PANIC: ", k, " not found in variable mapping"])
+ True = loadP $ 'Map'.find k g
+
+loadP :: LoadPlace -> Gen Instr
+loadP pl = dec pl >>= \(instr, arg)-> pure $ Instr instr [arg] ""
+where
+ dec (LDA i) = pure ("lda", Lit i)
+ dec (LDC i) = pure ("ldc", Lit i)
+ dec (LDH i) = pure ("ldh", Lit i)
+ dec (LDL i) = pure ("ldl", Lit i)
+ dec (LDR i) = pure ("ldr", Lit i)
+ dec (LDS i) = pure ("lds", Lit i)
+ dec _ = liftT (Left $ Error "PANIC: trying to load non adres")