8ac0c81 · elk · git.iko.soy

git.iko.soy/elk

Improve optimizations a bit. The compiler now performs beta reduction in some simple cases.

commit8ac0c81c1c8f64b995716fedfec670d3dabe5bdb authorevancz <info@elm-lang.org> dateThu 13 Sep 2012, 21:31 (14 years ago) parent8a79164

3 files changed+19−6

compare with master

unifiedsplit

elm/src/Gen/Cases.hs+1−1 elm/src/Optimize.hs+14−1 elm/src/Substitute.hs+4−4

elm/src/Gen/Cases.hs+1−1

@@ -45,7 +45,7 @@ match vs cs def

4545

4646matchVar :: [String] -> [([Pattern],Expr)] -> Match -> GuidCounter Match

4747matchVar (v:vs) cs def = match vs (map subVar cs) def

48− where subVar (PVar x : ps, e) = (ps, subst v x e)

48+ where subVar (PVar x : ps, e) = (ps, subst x (Var v) e)

4949 subVar (PAnything : ps, e) = (ps, e)

5050

5151matchCon :: [String] -> [([Pattern],Expr)] -> Match -> GuidCounter Match

elm/src/Optimize.hs+14−1

@@ -3,7 +3,7 @@ module Optimize (optimize) where

33import Ast

44import Control.Arrow (second)

55import Data.Char (isAlpha)

6−

6+import Substitute

88optimize (Module name ims exs stmts) =

99 Module name ims exs (map optimizeStmt stmts)

@@ -21,6 +21,9 @@ simp expr =

2121 Range e1 e2 -> Range (f e1) (f e2)

2222 Binop op e1 e2 -> simp_binop op (f e1) (f e2)

2323 Lambda x e -> Lambda x (f e)

24+ App (Lambda x e1) e2 ->

25+ if isValue e2' then subst x e2' e1' else App (Lambda x e1') e2'

26+ where { e1' = f e1 ; e2' = f e2 }

2427 App e1 e2 -> App (f e1) (f e2)

2528 If e1 e2 e3 -> simp_if (f e1) (f e2) (f e3)

2629 Let defs e -> Let (map simpDef defs) (f e)

@@ -32,6 +35,15 @@ simp expr =

3235simp_if (Boolean b) e2 e3 = if b then e2 else e3

3336simp_if a b c = If a b c

3437

38+isValue e = case e of { IntNum _ -> True

39+ ; FloatNum _ -> True

40+ ; Chr _ -> True

41+ ; Str _ -> True

42+ ; Boolean _ -> True

43+ ; Var _ -> True

44+ ; Data _ _ -> True

45+ ; _ -> False }

46+

3547simp_binop = binop

3648

3749binop op (IntNum n) (IntNum m) = f n m

@@ -87,6 +99,7 @@ binop "++" e (Data "Nil" []) = e

8799binop "++" (Data "Cons" [h,t]) e = Data "Cons" [h, binop "++" t e]

88100

89101binop "$" e1 e2 = App e1 e2

102+binop "." e1 e2 = Lambda "x" (App e1 (App e2 (Var "x")))

90103

91104binop op e1 e2

92105 | isAlpha (head op) || '_' == head op = App (App (Var op) e1) e2

elm/src/Substitute.hs+4−4

@@ -4,9 +4,9 @@ import Control.Arrow (second)

55import Ast

7−subst :: String -> String -> Expr -> Expr

8−subst new old expr =

9− let f = subst new old in

7+subst :: String -> Expr -> Expr -> Expr

8+subst old new expr =

9+ let f = subst old new in

1010 case expr of

1111 Range e1 e2 -> Range (f e1) (f e2)

1212 Access e x -> Access (f e) x

@@ -20,7 +20,7 @@ subst new old expr =

2020 Input _ -> expr

2121 Let defs e -> Let (map substDef defs) (f e)

2222 where substDef (Definition name vs e) = Definition name vs (f e)

23− Var x -> if x == old then Var new else expr

23+ Var x -> if x == old then new else expr

2424 Case e cases -> Case (f e) $ map (second f) cases

2525 Data name es -> Data name (map f es)

2626 _ -> expr