From ac2e692f8057d6f9c41817ff964561205b856c2c Mon Sep 17 00:00:00 2001
From: pimjager <pim@pimjager.nl>
Date: Sun, 8 May 2016 22:40:38 +0200
Subject: [PATCH] Start with gen for statements

---
 gen.icl | 59 ++++++++++++++++++++++++++++++++++++++++-----------------
 1 file changed, 42 insertions(+), 17 deletions(-)

diff --git a/gen.icl b/gen.icl
index d0ec628..b24830e 100644
--- a/gen.icl
+++ b/gen.icl
@@ -7,6 +7,8 @@ import StdOverloaded
 import StdString
 from StdFunc import id
 import StdTuple
+import StdEnum
+from StdEnv import const
 
 import Data.Func
 import qualified Data.Map as Map
@@ -28,34 +30,43 @@ import RWST
 TRUE :== -1
 FALSE :== 0
 :: Instr    = Instr String [Arg] String
-            | Lab String
+            | Lab Label
 :: Label :== String
 :: Arg = L Label | Lit Int
 :: SSMProgram :== [Instr]
-
-
-gen :: AST -> String
-gen _ = toString    [Lab "Test"
-                    ,Instr "ldc" [Lit 1] "Eerste instructie"
-                    ,Instr "ldc" [Lit 2] "Tweede instructie"]
-
-
-//Scrap this, we'll need shared state when generating
-//i.e. to figure out the positions of vars relative to the 
-//SP/MP/whatever or in which register they are 
-//and to supply with fresh labels 
-
-//The generation monad
 :: GenError = Error String
 :: GenMap :== 'Map'.Map String LoadPlace
 :: LoadPlace    = LDA Int | LDC Int | LDH Int | LDL Int 
                 | LDR Int | LDS Int
                 | FUNC Label
-:: Gen a :== RWST [Int] SSMProgram (GenMap, [Label]) (Either GenError) a
+:: Gen a :== RWST Label SSMProgram (GenMap, [Label]) (Either GenError) a
+
+labelStream :: [Label]
+labelStream = map (\i-> concat ["lab_", toString i]) [1..]
 
+gen :: AST -> String
+gen _ = prog
+    where
+        expr = (Op2Expr zero (Op1Expr zero UnMinus (IntExpr zero 4)) BiPlus (IntExpr zero 7))
+        expr2 = (FunExpr zero "test" [IntExpr zero 4] [])
+        stmt = (IfStmt (BoolExpr zero True) [] [])
+        prog = case evalRWST (g stmt) "end" ('Map'.newMap, labelStream) of
+            Left (Error e) = abort e
+            Right (_, prog) = toString prog
+//gen _ = toString    [Lab "Test"
+//                    ,Instr "ldc" [Lit 1] "Eerste instructie"
+//                    ,Instr "ldc" [Lit 2] "Tweede instructie"]
+
+
+//helper functions for the gen monad
 genMap :: Gen GenMap
 genMap = gets fst
 
+fresh :: Gen Label
+fresh = gets snd >>= \vars-> 
+        modify (appSnd $ const $ tail vars) >>| 
+        pure (head vars)
+
 class g a :: a -> Gen ()
 
 instance g Expr where
@@ -69,7 +80,21 @@ instance g Expr where
     g (Op1Expr _ UnMinus e) = g e >>| tell [Instr "neg" [] ""]
     g (EmptyListExpr _) = abort "Shit, empty list expr"
     g (TupleExpr p (e1,e2)) = abort "How to deal with tuples?"
-    g (FunExpr _ k es fs) = mapM g es >>| jump "bra" k >>= \instr-> tell [instr]
+    g (FunExpr _ k es fs) = mapM g es >>| jump "bsr" k >>= \instr-> tell [instr]
+            //bra is probably not right, figure out function call way
+
+instance g Stmt where
+    g (IfStmt cond th el) = 
+        fresh >>= \elseLabel->
+        fresh >>= \endLabel->
+        g cond >>|
+        tell [Instr "brf" [L elseLabel] "branch false"] >>|
+        mapM_ g th >>|
+        tell [Instr "bra" [L endLabel] "branch end if"] >>|
+        tell [Lab elseLabel] >>|
+        mapM_ g el  >>|
+        tell [Lab endLabel]
+
 
 op2ins :: Op2 -> String
 op2ins op = case op of
-- 
2.20.1