From f74dd82111c0f50fc7b1a222c796d258e82281fb Mon Sep 17 00:00:00 2001
From: Camil Staps
Date: Wed, 22 Nov 2017 11:19:41 +0100
Subject: Resolve run-time error for functions that use arguments twice further
 down the expression graph

---
 pf.icl | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

(limited to 'pf.icl')

diff --git a/pf.icl b/pf.icl
index 7e0f76f..46016e1 100644
--- a/pf.icl
+++ b/pf.icl
@@ -134,20 +134,20 @@ optim (Lambda id e)
 | otherwise = Ident "const" @ optim e
 where
 	optApp :: Expr -> Expr
-	optApp (f @ x)
-	| hasIdent id f && hasIdent id x = Ident "ap" @ Lambda id f @ Lambda id x
-	| otherwise = case moveOutside id (f @ x) of
+	optApp (f @ x) = case moveOutside id (f @ x) of
 		a=:(f @ Ident id`) -> if (id == id`) f (Ident "const" @ a)
 		a                  -> Ident "const" @ a
-optim (Ident "flip" @ Ident "ap" @ Ident "id") = Ident "join"
-optim (f @ x) = optim f @ optim x
+optim (f @ x) = case optim f @ optim x of
+	Ident "flip" @ Ident "ap" @ Ident "id" -> Ident "join"
+	Ident "ap" @ f @ Ident "id" -> Ident "join" @ f
+	e -> e
 optim e = e
 
 moveOutside :: Ident Expr -> Expr
 moveOutside _ (Ident id) = Ident id
 moveOutside _ (Literal l) = Literal l
 moveOutside id (f @ x)
-| hasIdent id f && hasIdent id x = abort "moveOutside on @ with id in both sides"
+| hasIdent id f && hasIdent id x = Ident "ap" @ Lambda id f @ Lambda id x @ Ident id
 | hasIdent id f = case moveOutside id f of
 	Ident id -> Ident "flip" @ Ident "id" @ x @ Ident id
 	g @ Ident id -> Ident "flip" @ g @ x @ Ident id
-- 
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