[lec9] Hands-on lab3 live code snippets

Author: andreasabel

README.md

@@ -50,8 +50,8 @@ Material: plt = course book, dragon = Dragon book. Slides follow closely the plt
 | Tue 26/11 | 13-14 | Hands-on with Lab 2 (Haskell) |  [script](notes/monads.html), [live code](live/2024/lab2-live-haskell.zip) |
 | Tue 26/11 | 14-15 | Hands-on with Lab 2 (Java)    | [script](notes/java.html), [Annotated.java](notes/Annotated.java) |
 | Thu 28/11 | 13-15 **SB-H5** | Code generation | [slides](plt-book/ipl-book/slides/6-slides-ipl-book.pdf), plt 6, dragon 6,7, [notes](notes/compilation.html), [prime.c](notes/prime.c), [prime.j](notes/prime.j) |
-| Tue 03/12 | 13-14 | Hands-on with Lab 3 (Haskell) |  |
-| Tue 03/12 | 14-15 | Hands-on with Lab 3 (Java)    |  |
+| Tue 03/12 | 13-14 | Hands-on with Lab 3 (Haskell) | [live code snippet](live/2024/lab3-live-haskell.hs) |
+| Tue 03/12 | 14-15 | Hands-on with Lab 3 (Java)    | [live code snippet](live/2024/lab3-live-java.java) |
 | *Wed 04/12* | *23* | *Lab 2 deadline* |  |
 | Thu 05/12 | 13-15 | Functional programming languages | [slides](plt-book/ipl-book/slides/7-slides-ipl-book.pdf), plt 7, dragon 6.5,7.3, [script](notes/cbn-cbv.html) |
 | Tue 10/12 | 13-15 | Type inference and polymorphism | plt 7.7-9, [script](notes/typing.html) |

live/2024/lab3-live-haskell.hs

@@ -0,0 +1,62 @@
+
+-- | Compile a function, to be called in initial environment.
+
+compileFun :: Type -> [Arg] -> [Stm] -> Compile ()
+compileFun t args ss = do
+    mapM_ (\ (ADecl t' x) -> newVar x t') args
+    mapM_ compileStm ss
+    -- Default return
+    -- Push 0 on the stack, depending on t
+    if t == Type_double then emit $ DConst 0.0 else
+      if t /= Type_void then emit $ IConst 0
+        else pure ()
+    emit $ Return t
+-- | Compile a statement.
+
+compileStm :: Stm -> Compile ()
+compileStm s0 = do
+
+  -- Output a comment with the statement to compile.
+  -- TODO
+
+  -- Compile the statement.
+  case s0 of
+
+    SDecl t x -> newVar x t
+    SExp t e -> do
+      compileExp e
+      emit $ Pop t
+    SReturn t e -> do
+      compileExp e
+      emit $ Return t
+    SBlock b -> compileBlock b
+    s -> error $ "Not yet implemented: compileStm " ++ printTree s
+
+-- | Compile a block.
+
+compileBlock :: Block -> Compile ()
+compileBlock (Block ss) = do
+  inNewBlock $ mapM_ compileStm ss
+
+
+-- | Compile an expression to leave its value on the stack.
+
+compileExp :: Exp -> Compile ()
+compileExp = \case
+    EInt i -> emit $ IConst i
+    EBool b -> emit $ IConst $ if b then 1 else 0
+    EId x -> do
+      (a, t) <- lookupVar x
+      emit $ Load t a
+    EAss x e -> do
+      compileExp e
+      (a, t) <- lookupVar x
+      emit $ Store t a
+      emit $ Load t a
+    EApp t x es -> do
+      mapM_ compileExp es
+      m <- gets sig
+      let f = Map.findWithDefault (error "undefined fun") x m
+      emit $ Call f
+
+    e -> error $ "Not yet implemented: compileExp " ++ printTree e

live/2024/lab3-live-java.java

@@ -0,0 +1,33 @@
+
+  void compile(Ann.Stm s) {
+    switch(s) {
+      case Ann.SDecl p -> { newVar(p.name(), p.type()); }
+      case Ann.SBlock p -> { newBlock(); compile(p.stms()); popBlock(); }
+      case Ann.SExp p -> { compile(p.exp()); emit(new Code.Pop(p.exp().type())); }
+      case Ann.SReturn p -> { compile(p.exp()); emit(new Code.Return(p.exp().type())); }
+
+      default -> throw new RuntimeException("compile(Stm): case nyi");
+    }
+  }
+
+  void compile(Ann.Exp e) {
+    switch(e) {
+      case Ann.EInt p -> { emit (new Code.IConst(p.lit()));}
+      case Ann.EAss p -> {
+        int addr = lookupVar(p.name()).addr();
+        compile(p.exp());
+        emit (new Code.Store(p.type(), addr));
+        emit (new Code.Load(p.type(), addr));
+      }
+      case Ann.EId p -> {
+        int addr = lookupVar(p.name()).addr();
+        emit (new Code.Load(p.type(), addr));
+      }
+      case Ann.EApp p -> {
+        for (Ann.Exp e1 : p.args()) compile(e1);
+        Fun f = lookupFun(p.fun());
+        emit(new Code.Call(f));
+      }
+      default -> throw new RuntimeException("compile(Exp): case nyi");
+    }
+  }