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Merge pull request #312217 from hsjobeki/doc/lib-derivations

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doc: migrate lib.derivations to doc-comment format
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Silvan Mosberger 2024-06-26 21:59:34 +02:00 committed by GitHub
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102
lib/derivations.nix
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@ -17,7 +17,7 @@ let
else "";
in
{
/*
/**
Restrict a derivation to a predictable set of attribute names, so
that the returned attrset is not strict in the actual derivation,
saving a lot of computation when the derivation is non-trivial.
@ -62,25 +62,36 @@ in
(lazyDerivation { inherit derivation }).pythonPath
# Inputs
Takes an attribute set with the following attributes
`derivation`
: The derivation to be wrapped.
`meta`
: Optional meta attribute.
While this function is primarily about derivations, it can improve
the `meta` package attribute, which is usually specified through
`mkDerivation`.
`passthru`
: Optional extra values to add to the returned attrset.
This can be used for adding package attributes, such as `tests`.
`outputs`
: Optional list of assumed outputs. Default: ["out"]
This must match the set of outputs that the returned derivation has.
You must use this when the derivation has multiple outputs.
*/
lazyDerivation =
args@{
# The derivation to be wrapped.
derivation
, # Optional meta attribute.
#
# While this function is primarily about derivations, it can improve
# the `meta` package attribute, which is usually specified through
# `mkDerivation`.
meta ? null
, # Optional extra values to add to the returned attrset.
#
# This can be used for adding package attributes, such as `tests`.
passthru ? { }
, # Optional list of assumed outputs. Default: ["out"]
#
# This must match the set of outputs that the returned derivation has.
# You must use this when the derivation has multiple outputs.
derivation,
meta ? null,
passthru ? { },
outputs ? [ "out" ]
}:
let
@ -149,29 +160,50 @@ in
// genAttrs outputs (outputName: checked.${outputName})
// passthru;
/* Conditionally set a derivation attribute.
/**
Conditionally set a derivation attribute.
Because `mkDerivation` sets `__ignoreNulls = true`, a derivation
attribute set to `null` will not impact the derivation output hash.
Thus, this function passes through its `value` argument if the `cond`
is `true`, but returns `null` if not.
Because `mkDerivation` sets `__ignoreNulls = true`, a derivation
attribute set to `null` will not impact the derivation output hash.
Thus, this function passes through its `value` argument if the `cond`
is `true`, but returns `null` if not.
Type: optionalDrvAttr :: Bool -> a -> a | Null
Example:
(stdenv.mkDerivation {
name = "foo";
x = optionalDrvAttr true 1;
y = optionalDrvAttr false 1;
}).drvPath == (stdenv.mkDerivation {
name = "foo";
x = 1;
}).drvPath
=> true
# Inputs
`cond`
: Condition
`value`
: Attribute value
# Type
```
optionalDrvAttr :: Bool -> a -> a | Null
```
# Examples
:::{.example}
## `lib.derivations.optionalDrvAttr` usage example
```nix
(stdenv.mkDerivation {
name = "foo";
x = optionalDrvAttr true 1;
y = optionalDrvAttr false 1;
}).drvPath == (stdenv.mkDerivation {
name = "foo";
x = 1;
}).drvPath
=> true
```
:::
*/
optionalDrvAttr =
# Condition
cond:
# Attribute value
value: if cond then value else null;
}