1ac9dcd24d
derivation evaluate inside the tryEval. This catches cases such as aufs2-util, which fails due to an assertion in its dependency aufs2. * Explicitly blacklist "xbursttools" because it gives some evaluation error in cross-OpenSSL. No idea why, probably due to some pass-through attribute. svn path=/nixpkgs/trunk/; revision=23247
25 lines
597 B
Nix
25 lines
597 B
Nix
rec {
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# Identity function.
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id = x: x;
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# Constant function.
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const = x: y: x;
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# Named versions corresponding to some builtin operators.
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concat = x: y: x ++ y;
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or = x: y: x || y;
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and = x: y: x && y;
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mergeAttrs = x: y: x // y;
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# Take a function and evaluate it with its own returned value.
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fix = f: let result = f result; in result;
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# Flip the order of the arguments of a binary function.
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flip = f: a: b: f b a;
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# `seq x y' evaluates x, then returns y. That is, it forces strict
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# evaluation of its first argument.
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seq = x: y: if x == null then y else y;
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}
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