3 commits

Author	SHA1	Message	Date
Eelco Dolstra	8a10360c91	* Simplify @-patterns: only {attrs}@name' or name@{attrs}' are now ... allowed. So `name1@name2', `{attrs1}@{attrs2}' and so on are now no longer legal. This is no big loss because they were not useful anyway. This also changes the output of builtins.toXML for @-patterns slightly.	2010-03-25 12:19:41 +00:00
Eelco Dolstra	9279174dde	* Added an experimental feature suggested by Andres: ellipses ("...") ... in attribute set pattern matches. This allows defining a function that takes *at least* the listed attributes, while ignoring additional attributes. For instance, {stdenv, fetchurl, fuse, ...}: stdenv.mkDerivation { ... }; defines a function that requires an attribute set that contains the specified attributes but ignores others. The main advantage is that we can then write in all-packages.nix aefs = import ../bla/aefs pkgs; instead of aefs = import ../bla/aefs { inherit stdenv fetchurl fuse; }; This saves a lot of typing (not to mention not having to update all-packages.nix with purely mechanical changes). It saves as much typing as the "args: with args;" style, but has the advantage that the function arguments are properly declared (not implicit in what the body of the "with" uses).	2008-08-14 14:00:44 +00:00
Eelco Dolstra	1b962fc720	* @-patterns as in Haskell. For instance, in a function definition ... f = args @ {x, y, z}: ...; `args' refers to the argument as a whole, which is further pattern-matched against the attribute set pattern {x, y, z}.	2008-08-14 12:53:29 +00:00