+ g (IntExpr _ i) = tell [Instr "ldc" [Lit i] ""]
+ g (CharExpr _ c) = tell [Instr "ldc" [Lit (toInt c)] ""]
+ g (BoolExpr _ b) = tell [Instr "ldc" [Lit (if b TRUE FALSE)] ""]
+ g (EmptyListExpr _) = tell [Instr "ldc" [Lit 0] ""]
+ >>| tell [Instr "sth" [] ""]
+ g (Op1Expr _ o e) = g e >>| g o
+ g (Op2Expr _ e1 BiCons e2) = g e2 >>| g e1
+ >>| tell [Instr "sth" [] ""]
+ >>| tell [Instr "ajs" [Lit -1] ""]
+ >>| tell [Instr "sth" [] ""]
+ g (Op2Expr _ e1 op e2) = g e1 >>| g e2 >>| g op
+ g (TupleExpr _ (e1,e2)) = g e1
+ >>| tell [Instr "sth" [] ""]
+ >>| g e2
+ >>| tell [Instr "sth" [] ""]
+ >>| tell [Instr "ajs" [Lit -1] ""]
+ g (VarExpr _ (VarDef k fs)) = getAdressbook >>= \ab->case 'Map'.get k ab of
+ Nothing = liftT (Left $ Error "PANIC: undefined variable")
+ Just (ADDR t) = tell [Instr "ldl" [Lit t] ""]
+ Just (LAB t) = liftT (Left $ Error "PANIC: variable and function name clash")
+ //load k >>= \instr-> tell [instr] //note: pure is pure for list, i.e. []
+ g (FunExpr _ k es fs) =
+ mapM_ g es
+ >>| jump "bsr" k
+ >>| mapM_ (const $ tell [Instr "ajs" [Lit -1] ""]) es //clean up args
+ >>| tell [Instr "ldr" [Raw "RR"] ""]
+
+jump :: String String -> Gen ()
+jump instr k = getAdressbook >>= \ab->case 'Map'.get k ab of
+ Nothing = liftT (Left $ Error $ concat ["PANIC: ", k, " not found as function"])
+ Just (LAB t) = tell [Instr instr [L t] (k +++"()")]
+ Just (ADDR t) = liftT (Left $ Error $ "PANIC: jump should go to label")
+
+instance g Stmt where
+ g (IfStmt cond th el) =
+ fresh >>= \elseLabel->
+ fresh >>= \endLabel->
+ g cond >>|
+ tell [Instr "brf" [L elseLabel] "branch else"] >>|
+ mapM_ g th >>|
+ tell [Instr "bra" [L endLabel] "branch end if"] >>|
+ tell [Lab elseLabel] >>|
+ mapM_ g el >>|
+ tell [Lab endLabel]
+ g (WhileStmt cond th) =
+ fresh >>= \startLabel->
+ fresh >>= \endLabel ->
+ tell [Lab startLabel] >>|
+ g cond >>|
+ tell [Instr "brf" [L endLabel] "branch end while"] >>|
+ mapM_ g th >>|
+ tell [Instr "bra" [L startLabel] "branch start while"] >>|
+ tell [Lab endLabel]
+ g (AssStmt (VarDef k fs) e) =
+ g e >>| getAdressbook >>= \ab->case 'Map'.get k ab of
+ Nothing = liftT (Left $ Error $ concat ["PANIC: ", k, " not found as var"])
+ Just (LAB t) = liftT (Left $ Error $ "PANIC: cannot assign to function")
+ Just (ADDR t) = tell [Instr "stl" [Lit t] ""]
+ g (FunStmt k es) = mapM_ g es
+ >>| mapM_ (const $ tell [Instr "ajs" [Lit -1] ""]) es //clean up args
+ >>| jump "bsr" k
+ g (ReturnStmt Nothing) = tell [Instr "unlink" [] ""]
+ >>| tell [Instr "ret" [] ""]
+ g (ReturnStmt (Just e)) = g e
+ >>| tell [Instr "str" [Raw "RR"] ""]
+ >>| g (ReturnStmt Nothing)
+
+foldVarDecl :: Int VarDecl -> Gen Int
+foldVarDecl x (VarDecl _ _ k e) = g e
+ >>| annote x k
+ >>| updateAdressbook (extend k (ADDR x)) >>| pure (x + 1)
+
+addVars :: [String] -> (Addressbook -> Addressbook)
+addVars [] = id
+addVars [x:xs] = \ab->extend x (ADDR (-2 - (length xs))) (addVars xs ab)
+
+instance g FunDecl where
+ g (FunDecl _ k args _ vds stms) =
+ //varDecls can call the enclosing function, so first reserve a label for it
+ updateAdressbook (extend k (LAB k)) >>|
+ getAdressbook >>= \oldMap ->
+ updateAdressbook (addVars args) >>|
+ tell [Lab k] >>|
+ tell [Instr "link" [Lit 0] ""] >>|
+ //add the vars
+ foldM foldVarDecl 1 vds >>|
+ //and the statements
+ mapM_ g stms >>|
+ updateAdressbook (const oldMap) >>| pure ()
+
+annote :: Int -> String -> Gen ()
+annote pos key =
+ tell [Instr "annote" [Raw "MP", Lit pos, Lit pos, Raw "orange", Raw key] ""]