From 97e15cc2b8e7642ced353cd210169b32c289fd2d Mon Sep 17 00:00:00 2001
From: Michael Raskin <7c6f434c@mail.ru>
Date: Wed, 20 Aug 2008 06:45:14 +0000
Subject: [PATCH] Noticed an associativity direction problem
svn path=/nixpkgs/trunk/; revision=12664
---
pkgs/lib/default.nix | 22 +++++++++++++---------
1 file changed, 13 insertions(+), 9 deletions(-)
diff --git a/pkgs/lib/default.nix b/pkgs/lib/default.nix
index a23b7d947efd..cdf1b2f174f5 100644
--- a/pkgs/lib/default.nix
+++ b/pkgs/lib/default.nix
@@ -32,16 +32,20 @@ rec {
else (innerComposedArgs f (y x))));
composedArgs = f: innerComposedArgs f {};
+ defaultMerge = x : y: if builtins.isAttrs y then
+ x // y
+ else
+ y x;
sumTwoArgs = f: x: y:
- if builtins.isAttrs y then
- (f (x // y))
- else
- (f (y x));
- composedArgsAndFun = f : x : (f x) // {
- meta = {
- function = composedArgsAndFun (sumTwoArgs f x);
- };
- };
+ f (defaultMerge x y);
+ foldArgs = merger: f: init: x:
+ let arg=(merger init (defaultMerge init x)); in
+ (f arg) // {
+ meta = {
+ function = foldArgs merger f arg;
+ };
+ };
+ composedArgsAndFun = f: foldArgs (x: y: y) {} f;
# example a = pairMap (x : y : x + y) ["a" "b" "c" "d"];
# result: ["ab" "cd"]