From f081c2c5e248331eb6e2f090f4afe818fd8259eb Mon Sep 17 00:00:00 2001
From: pimjager <pim@pimjager.nl>
Date: Thu, 19 May 2016 18:05:38 +0200
Subject: [PATCH] Added default functions, isEmpty does not typecheck...

---
 examples/codeGen.spl | 44 +++++++++++++++++++++++++++++-------------
 gen.icl              | 46 ++++++++++++++++++++++++++++++++------------
 sem.icl              |  8 +++++++-
 3 files changed, 72 insertions(+), 26 deletions(-)

diff --git a/examples/codeGen.spl b/examples/codeGen.spl
index 34474a7..ebede23 100644
--- a/examples/codeGen.spl
+++ b/examples/codeGen.spl
@@ -1,18 +1,36 @@
-f(x, y) {
-    var ret = 0;
-    if (x < y) {
-	   ret = x;
-    }
-    else {
-        ret = y;
+//f(x, y) {
+//    var ret = 0;
+//    if (x < y) {
+//	   ret = x;
+//    }
+//    else {
+//        ret = y;
+//    }
+//    return ret;
+//}//
+
+//main() {
+//	Int x1 = 1;
+//    var x2 = 4;
+//    var x3 = f(x1, x2);
+//    print(x1);
+//    x1 = 5;
+//    return x3 + x1;
+//}
+
+isE(x) :: [a] -> Bool {
+    if (x == []) {
+        return True;
+    } else {
+        return False;
     }
-    return ret;
 }
 
 main() {
-	Int x1 = 1;
-    var x2 = 4;
-    var x3 = f(x1, x2);
-    x1 = 5;
-    return x3 + x1;
+    [Int] x1 = 1 : 2 : [];
+    [Int] x2 = 0 : x1;
+    [Int] x3 = [];
+    //Bool y1 = isEmpty(x2); //gives weird type error, not sure why
+    isEmpty(x2);
+    return;
 }
diff --git a/gen.icl b/gen.icl
index 89af77c..d139804 100644
--- a/gen.icl
+++ b/gen.icl
@@ -39,24 +39,45 @@ FALSE :== 0
 labelStream :: [Label]
 labelStream = ["lbl_" +++ toString i\\i<-[1..]]
 
+defaultAddressBook :: Addressbook 
+defaultAddressBook = extend "print" (LAB "print")
+                        $ extend "read" (LAB "read")
+                        $ extend "isEmpty" (LAB "isEmpty")
+                        'Map'.newMap
+
 gen :: AST -> Either String String
-gen (AST fds) = case evalRWST prog () ('Map'.newMap, labelStream) of
+gen (AST fds) = case evalRWST prog () (defaultAddressBook, labelStream) of
             Left (Error e) = Left e
             Right (_, p) = Right $ toString p
     where
         prog = tell [
 			Instr "bsr" [L "main"] "",
 			Instr "halt" [] ""
-			] >>| mapM_ g fds
-
-//Current issues:
-//All VarDecls are added as function, how to deal with assignments?
-//  (And when we deal with assignments, how to deal with assignments to higher order functions?)
-//Dealing with arguments
-//Dealing with types that do not fit on the Stack
-//  Probably completely change LoadPlace to a Type and a position relative to *something*
-//  And where the type determines if this position is a pointer to the heap or an
-//  unboxed value
+			] >>| tell programContext
+            >>| mapM_ g fds
+
+programContext :: SSMProgram
+programContext =    [Lab "print" //there is no actual IO in SSM
+                    ,Instr "link" [Lit 0] ""
+                    ,Instr "unlink" [] ""
+                    ,Instr "ret" [] ""
+                    ,Lab "read" //there is no actual IO in SSM
+                    ,Instr "link" [Lit 0] ""
+                    ,Instr "ldc" [Lit 0] ""
+                    ,Instr "sth" [] ""
+                    ,Instr "str" [Raw "RR"] ""
+                    ,Instr "unlink" [] ""
+                    ,Instr "ret" [] ""
+                    ,Lab "isEmpty"
+                    ,Instr "link" [Lit 0] ""
+                    ,Instr "ldl" [Lit -2] "load prt to list"
+                    ,Instr "lda" [Lit 0] "derefrence ptr"
+                    ,Instr "ldc" [Lit 0] ""
+                    ,Instr "eq" [] "test for null pointer"
+                    ,Instr "str" [Raw "RR"] ""
+                    ,Instr "unlink" [] ""
+                    ,Instr "ret" [] ""
+                    ]
 
 //helper functions for the gen monad
 getAdressbook :: Gen Addressbook
@@ -158,8 +179,9 @@ instance g Stmt where
             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
+        >>| mapM_ (const $ tell [Instr "ajs" [Lit -1] ""]) es //clean up args
+        >>| pure ()
     g (ReturnStmt Nothing) = tell [Instr "unlink" [] ""]
 		>>| tell [Instr "ret" [] ""]
     g (ReturnStmt (Just e)) = g e
diff --git a/sem.icl b/sem.icl
index af49fdf..0da9c77 100644
--- a/sem.icl
+++ b/sem.icl
@@ -48,11 +48,17 @@ instance zero Gamma where
 variableStream :: [TVar]
 variableStream = map toString [1..]
 
+defaultGamma :: Gamma //includes all default functions
+defaultGamma = extend "print" (Forall ["a"] ((IdType "a") ->> VoidType))
+                $ extend "isEmpty" (Forall ["a"] (ListType (IdType "a") ->> BoolType))
+                $ extend "read" (Forall [] (IntType ->> (ListType CharType)))
+                zero
+
 sem :: AST -> Either [SemError] AST
 sem (AST fd) = case foldM (const $ hasNoDups fd) () fd 
             		>>| foldM (const isNiceMain) () fd
             		>>| hasMain fd
-                    >>| evalStateT (type fd) (zero, variableStream) of
+                    >>| evalStateT (type fd) (defaultGamma, variableStream) of
 	Left e = Left [e]
     Right (_,fds) = Right (AST fds)
 where
-- 
2.20.1