9279174dde
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).
19 lines
183 B
Nix
19 lines
183 B
Nix
rec {
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x = 123;
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a = "foo";
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b = "bar";
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c = "foo" + "bar";
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f = {z, x, y}: if y then x else z;
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id = x: x;
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at = args@{x, y, z}: x;
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ellipsis = {x, y, z, ...}: x;
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}
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