nixpkgs/lib/meta.nix
2018-05-09 16:21:22 -05:00

90 lines
2.3 KiB
Nix

/* Some functions for manipulating meta attributes, as well as the
name attribute. */
{ lib }:
rec {
/* Add to or override the meta attributes of the given
derivation.
Example:
addMetaAttrs {description = "Bla blah";} somePkg
*/
addMetaAttrs = newAttrs: drv:
drv // { meta = (drv.meta or {}) // newAttrs; };
/* Disable Hydra builds of given derivation.
*/
dontDistribute = drv: addMetaAttrs { hydraPlatforms = []; } drv;
/* Change the symbolic name of a package for presentation purposes
(i.e., so that nix-env users can tell them apart).
*/
setName = name: drv: drv // {inherit name;};
/* Like `setName', but takes the previous name as an argument.
Example:
updateName (oldName: oldName + "-experimental") somePkg
*/
updateName = updater: drv: drv // {name = updater (drv.name);};
/* Append a suffix to the name of a package (before the version
part). */
appendToName = suffix: updateName (name:
let x = builtins.parseDrvName name; in "${x.name}-${suffix}-${x.version}");
/* Apply a function to each derivation and only to derivations in an attrset
*/
mapDerivationAttrset = f: set: lib.mapAttrs (name: pkg: if lib.isDerivation pkg then (f pkg) else pkg) set;
/* Decrease the nix-env priority of the package, i.e., other
versions/variants of the package will be preferred.
*/
lowPrio = drv: addMetaAttrs { priority = 10; } drv;
/* Apply lowPrio to an attrset with derivations
*/
lowPrioSet = set: mapDerivationAttrset lowPrio set;
/* Increase the nix-env priority of the package, i.e., this
version/variant of the package will be preferred.
*/
hiPrio = drv: addMetaAttrs { priority = -10; } drv;
/* Apply hiPrio to an attrset with derivations
*/
hiPrioSet = set: mapDerivationAttrset hiPrio set;
/* Check to see if a platform is matched by the given `meta.platforms`
element.
A `meta.platform` pattern is either
1. (legacy) a system string.
2. (modern) a pattern for the platform `parsed` field.
We can inject these into a patten for the whole of a structured platform,
and then match that.
*/
platformMatch = platform: elem: let
pattern =
if builtins.isString elem
then { system = elem; }
else { parsed = elem; };
in lib.matchAttrs pattern platform;
}