{ lib }:
# Operations on attribute sets.
let
inherit (builtins) head tail length;
inherit (lib.trivial) id mergeAttrs;
inherit (lib.strings) concatStringsSep concatMapStringsSep escapeNixIdentifier sanitizeDerivationName;
inherit (lib.lists) foldr foldl' concatMap concatLists elemAt all partition groupBy take foldl;
in
rec {
inherit (builtins) attrNames listToAttrs hasAttr isAttrs getAttr removeAttrs;
/* Return an attribute from nested attribute sets.
Example:
x = { a = { b = 3; }; }
# ["a" "b"] is equivalent to x.a.b
# 6 is a default value to return if the path does not exist in attrset
attrByPath ["a" "b"] 6 x
=> 3
attrByPath ["z" "z"] 6 x
=> 6
Type:
attrByPath :: [String] -> Any -> AttrSet -> Any
*/
attrByPath =
# A list of strings representing the attribute path to return from `set`
attrPath:
# Default value if `attrPath` does not resolve to an existing value
default:
# The nested attribute set to select values from
set:
let attr = head attrPath;
in
if attrPath == [] then set
else if set ? ${attr}
then attrByPath (tail attrPath) default set.${attr}
else default;
/* Return if an attribute from nested attribute set exists.
Example:
x = { a = { b = 3; }; }
hasAttrByPath ["a" "b"] x
=> true
hasAttrByPath ["z" "z"] x
=> false
Type:
hasAttrByPath :: [String] -> AttrSet -> Bool
*/
hasAttrByPath =
# A list of strings representing the attribute path to check from `set`
attrPath:
# The nested attribute set to check
e:
let attr = head attrPath;
in
if attrPath == [] then true
else if e ? ${attr}
then hasAttrByPath (tail attrPath) e.${attr}
else false;
/* Create a new attribute set with `value` set at the nested attribute location specified in `attrPath`.
Example:
setAttrByPath ["a" "b"] 3
=> { a = { b = 3; }; }
Type:
setAttrByPath :: [String] -> Any -> AttrSet
*/
setAttrByPath =
# A list of strings representing the attribute path to set
attrPath:
# The value to set at the location described by `attrPath`
value:
let
len = length attrPath;
atDepth = n:
if n == len
then value
else { ${elemAt attrPath n} = atDepth (n + 1); };
in atDepth 0;
/* Like `attrByPath`, but without a default value. If it doesn't find the
path it will throw an error.
Example:
x = { a = { b = 3; }; }
getAttrFromPath ["a" "b"] x
=> 3
getAttrFromPath ["z" "z"] x
=> error: cannot find attribute `z.z'
Type:
getAttrFromPath :: [String] -> AttrSet -> Any
*/
getAttrFromPath =
# A list of strings representing the attribute path to get from `set`
attrPath:
# The nested attribute set to find the value in.
set:
let errorMsg = "cannot find attribute `" + concatStringsSep "." attrPath + "'";
in attrByPath attrPath (abort errorMsg) set;
/* Map each attribute in the given set and merge them into a new attribute set.
Type:
concatMapAttrs :: (String -> a -> AttrSet) -> AttrSet -> AttrSet
Example:
concatMapAttrs
(name: value: {
${name} = value;
${name + value} = value;
})
{ x = "a"; y = "b"; }
=> { x = "a"; xa = "a"; y = "b"; yb = "b"; }
*/
concatMapAttrs = f: v:
foldl' mergeAttrs { }
(attrValues
(mapAttrs f v)
);
/* Update or set specific paths of an attribute set.
Takes a list of updates to apply and an attribute set to apply them to,
and returns the attribute set with the updates applied. Updates are
represented as `{ path = ...; update = ...; }` values, where `path` is a
list of strings representing the attribute path that should be updated,
and `update` is a function that takes the old value at that attribute path
as an argument and returns the new
value it should be.
Properties:
- Updates to deeper attribute paths are applied before updates to more
shallow attribute paths
- Multiple updates to the same attribute path are applied in the order
they appear in the update list
- If any but the last `path` element leads into a value that is not an
attribute set, an error is thrown
- If there is an update for an attribute path that doesn't exist,
accessing the argument in the update function causes an error, but
intermediate attribute sets are implicitly created as needed
Example:
updateManyAttrsByPath [
{
path = [ "a" "b" ];
update = old: { d = old.c; };
}
{
path = [ "a" "b" "c" ];
update = old: old + 1;
}
{
path = [ "x" "y" ];
update = old: "xy";
}
] { a.b.c = 0; }
=> { a = { b = { d = 1; }; }; x = { y = "xy"; }; }
Type: updateManyAttrsByPath :: [{ path :: [String]; update :: (Any -> Any); }] -> AttrSet -> AttrSet
*/
updateManyAttrsByPath = let
# When recursing into attributes, instead of updating the `path` of each
# update using `tail`, which needs to allocate an entirely new list,
# we just pass a prefix length to use and make sure to only look at the
# path without the prefix length, so that we can reuse the original list
# entries.
go = prefixLength: hasValue: value: updates:
let
# Splits updates into ones on this level (split.right)
# And ones on levels further down (split.wrong)
split = partition (el: length el.path == prefixLength) updates;
# Groups updates on further down levels into the attributes they modify
nested = groupBy (el: elemAt el.path prefixLength) split.wrong;
# Applies only nested modification to the input value
withNestedMods =
# Return the value directly if we don't have any nested modifications
if split.wrong == [] then
if hasValue then value
else
# Throw an error if there is no value. This `head` call here is
# safe, but only in this branch since `go` could only be called
# with `hasValue == false` for nested updates, in which case
# it's also always called with at least one update
let updatePath = (head split.right).path; in
throw
( "updateManyAttrsByPath: Path '${showAttrPath updatePath}' does "
+ "not exist in the given value, but the first update to this "
+ "path tries to access the existing value.")
else
# If there are nested modifications, try to apply them to the value
if ! hasValue then
# But if we don't have a value, just use an empty attribute set
# as the value, but simplify the code a bit
mapAttrs (name: go (prefixLength + 1) false null) nested
else if isAttrs value then
# If we do have a value and it's an attribute set, override it
# with the nested modifications
value //
mapAttrs (name: go (prefixLength + 1) (value ? ${name}) value.${name}) nested
else
# However if it's not an attribute set, we can't apply the nested
# modifications, throw an error
let updatePath = (head split.wrong).path; in
throw
( "updateManyAttrsByPath: Path '${showAttrPath updatePath}' needs to "
+ "be updated, but path '${showAttrPath (take prefixLength updatePath)}' "
+ "of the given value is not an attribute set, so we can't "
+ "update an attribute inside of it.");
# We get the final result by applying all the updates on this level
# after having applied all the nested updates
# We use foldl instead of foldl' so that in case of multiple updates,
# intermediate values aren't evaluated if not needed
in foldl (acc: el: el.update acc) withNestedMods split.right;
in updates: value: go 0 true value updates;
/* Return the specified attributes from a set.
Example:
attrVals ["a" "b" "c"] as
=> [as.a as.b as.c]
Type:
attrVals :: [String] -> AttrSet -> [Any]
*/
attrVals =
# The list of attributes to fetch from `set`. Each attribute name must exist on the attrbitue set
nameList:
# The set to get attribute values from
set: map (x: set.${x}) nameList;
/* Return the values of all attributes in the given set, sorted by
attribute name.
Example:
attrValues {c = 3; a = 1; b = 2;}
=> [1 2 3]
Type:
attrValues :: AttrSet -> [Any]
*/
attrValues = builtins.attrValues or (attrs: attrVals (attrNames attrs) attrs);
/* Given a set of attribute names, return the set of the corresponding
attributes from the given set.
Example:
getAttrs [ "a" "b" ] { a = 1; b = 2; c = 3; }
=> { a = 1; b = 2; }
Type:
getAttrs :: [String] -> AttrSet -> AttrSet
*/
getAttrs =
# A list of attribute names to get out of `set`
names:
# The set to get the named attributes from
attrs: genAttrs names (name: attrs.${name});
/* Collect each attribute named `attr` from a list of attribute
sets. Sets that don't contain the named attribute are ignored.
Example:
catAttrs "a" [{a = 1;} {b = 0;} {a = 2;}]
=> [1 2]
Type:
catAttrs :: String -> [AttrSet] -> [Any]
*/
catAttrs = builtins.catAttrs or
(attr: l: concatLists (map (s: if s ? ${attr} then [s.${attr}] else []) l));
/* Filter an attribute set by removing all attributes for which the
given predicate return false.
Example:
filterAttrs (n: v: n == "foo") { foo = 1; bar = 2; }
=> { foo = 1; }
Type:
filterAttrs :: (String -> Any -> Bool) -> AttrSet -> AttrSet
*/
filterAttrs =
# Predicate taking an attribute name and an attribute value, which returns `true` to include the attribute, or `false` to exclude the attribute.
pred:
# The attribute set to filter
set:
listToAttrs (concatMap (name: let v = set.${name}; in if pred name v then [(nameValuePair name v)] else []) (attrNames set));
/* Filter an attribute set recursively by removing all attributes for
which the given predicate return false.
Example:
filterAttrsRecursive (n: v: v != null) { foo = { bar = null; }; }
=> { foo = {}; }
Type:
filterAttrsRecursive :: (String -> Any -> Bool) -> AttrSet -> AttrSet
*/
filterAttrsRecursive =
# Predicate taking an attribute name and an attribute value, which returns `true` to include the attribute, or `false` to exclude the attribute.
pred:
# The attribute set to filter
set:
listToAttrs (
concatMap (name:
let v = set.${name}; in
if pred name v then [
(nameValuePair name (
if isAttrs v then filterAttrsRecursive pred v
else v
))
] else []
) (attrNames set)
);
/*
Like builtins.foldl' but for attribute sets.
Iterates over every name-value pair in the given attribute set.
The result of the callback function is often called `acc` for accumulator. It is passed between callbacks from left to right and the final `acc` is the return value of `foldlAttrs`.
Attention:
There is a completely different function
`lib.foldAttrs`
which has nothing to do with this function, despite the similar name.
Example:
foldlAttrs
(acc: name: value: {
sum = acc.sum + value;
names = acc.names ++ [name];
})
{ sum = 0; names = []; }
{
foo = 1;
bar = 10;
}
->
{
sum = 11;
names = ["bar" "foo"];
}
foldlAttrs
(throw "function not needed")
123
{};
->
123
foldlAttrs
(_: _: v: v)
(throw "initial accumulator not needed")
{ z = 3; a = 2; };
->
3
The accumulator doesn't have to be an attrset.
It can be as simple as a number or string.
foldlAttrs
(acc: _: v: acc * 10 + v)
1
{ z = 1; a = 2; };
->
121
Type:
foldlAttrs :: ( a -> String -> b -> a ) -> a -> { ... :: b } -> a
*/
foldlAttrs = f: init: set:
foldl'
(acc: name: f acc name set.${name})
init
(attrNames set);
/* Apply fold functions to values grouped by key.
Example:
foldAttrs (item: acc: [item] ++ acc) [] [{ a = 2; } { a = 3; }]
=> { a = [ 2 3 ]; }
Type:
foldAttrs :: (Any -> Any -> Any) -> Any -> [AttrSets] -> Any
*/
foldAttrs =
# A function, given a value and a collector combines the two.
op:
# The starting value.
nul:
# A list of attribute sets to fold together by key.
list_of_attrs:
foldr (n: a:
foldr (name: o:
o // { ${name} = op n.${name} (a.${name} or nul); }
) a (attrNames n)
) {} list_of_attrs;
/* Recursively collect sets that verify a given predicate named `pred`
from the set `attrs`. The recursion is stopped when the predicate is
verified.
Example:
collect isList { a = { b = ["b"]; }; c = [1]; }
=> [["b"] [1]]
collect (x: x ? outPath)
{ a = { outPath = "a/"; }; b = { outPath = "b/"; }; }
=> [{ outPath = "a/"; } { outPath = "b/"; }]
Type:
collect :: (AttrSet -> Bool) -> AttrSet -> [x]
*/
collect =
# Given an attribute's value, determine if recursion should stop.
pred:
# The attribute set to recursively collect.
attrs:
if pred attrs then
[ attrs ]
else if isAttrs attrs then
concatMap (collect pred) (attrValues attrs)
else
[];
/* Return the cartesian product of attribute set value combinations.
Example:
cartesianProductOfSets { a = [ 1 2 ]; b = [ 10 20 ]; }
=> [
{ a = 1; b = 10; }
{ a = 1; b = 20; }
{ a = 2; b = 10; }
{ a = 2; b = 20; }
]
Type:
cartesianProductOfSets :: AttrSet -> [AttrSet]
*/
cartesianProductOfSets =
# Attribute set with attributes that are lists of values
attrsOfLists:
foldl' (listOfAttrs: attrName:
concatMap (attrs:
map (listValue: attrs // { ${attrName} = listValue; }) attrsOfLists.${attrName}
) listOfAttrs
) [{}] (attrNames attrsOfLists);
/* Utility function that creates a `{name, value}` pair as expected by `builtins.listToAttrs`.
Example:
nameValuePair "some" 6
=> { name = "some"; value = 6; }
Type:
nameValuePair :: String -> Any -> { name :: String; value :: Any; }
*/
nameValuePair =
# Attribute name
name:
# Attribute value
value:
{ inherit name value; };
/* Apply a function to each element in an attribute set, creating a new attribute set.
Example:
mapAttrs (name: value: name + "-" + value)
{ x = "foo"; y = "bar"; }
=> { x = "x-foo"; y = "y-bar"; }
Type:
mapAttrs :: (String -> Any -> Any) -> AttrSet -> AttrSet
*/
mapAttrs = builtins.mapAttrs or
(f: set:
listToAttrs (map (attr: { name = attr; value = f attr set.${attr}; }) (attrNames set)));
/* Like `mapAttrs`, but allows the name of each attribute to be
changed in addition to the value. The applied function should
return both the new name and value as a `nameValuePair`.
Example:
mapAttrs' (name: value: nameValuePair ("foo_" + name) ("bar-" + value))
{ x = "a"; y = "b"; }
=> { foo_x = "bar-a"; foo_y = "bar-b"; }
Type:
mapAttrs' :: (String -> Any -> { name :: String; value :: Any; }) -> AttrSet -> AttrSet
*/
mapAttrs' =
# A function, given an attribute's name and value, returns a new `nameValuePair`.
f:
# Attribute set to map over.
set:
listToAttrs (map (attr: f attr set.${attr}) (attrNames set));
/* Call a function for each attribute in the given set and return
the result in a list.
Example:
mapAttrsToList (name: value: name + value)
{ x = "a"; y = "b"; }
=> [ "xa" "yb" ]
Type:
mapAttrsToList :: (String -> a -> b) -> AttrSet -> [b]
*/
mapAttrsToList =
# A function, given an attribute's name and value, returns a new value.
f:
# Attribute set to map over.
attrs:
map (name: f name attrs.${name}) (attrNames attrs);
/* Like `mapAttrs`, except that it recursively applies itself to
the *leaf* attributes of a potentially-nested attribute set:
the second argument of the function will never be an attrset.
Also, the first argument of the argument function is a *list*
of the attribute names that form the path to the leaf attribute.
For a function that gives you control over what counts as a leaf,
see `mapAttrsRecursiveCond`.
Example:
mapAttrsRecursive (path: value: concatStringsSep "-" (path ++ [value]))
{ n = { a = "A"; m = { b = "B"; c = "C"; }; }; d = "D"; }
=> { n = { a = "n-a-A"; m = { b = "n-m-b-B"; c = "n-m-c-C"; }; }; d = "d-D"; }
Type:
mapAttrsRecursive :: ([String] -> a -> b) -> AttrSet -> AttrSet
*/
mapAttrsRecursive =
# A function, given a list of attribute names and a value, returns a new value.
f:
# Set to recursively map over.
set:
mapAttrsRecursiveCond (as: true) f set;
/* Like `mapAttrsRecursive`, but it takes an additional predicate
function that tells it whether to recurse into an attribute
set. If it returns false, `mapAttrsRecursiveCond` does not
recurse, but does apply the map function. If it returns true, it
does recurse, and does not apply the map function.
Example:
# To prevent recursing into derivations (which are attribute
# sets with the attribute "type" equal to "derivation"):
mapAttrsRecursiveCond
(as: !(as ? "type" && as.type == "derivation"))
(x: ... do something ...)
attrs
Type:
mapAttrsRecursiveCond :: (AttrSet -> Bool) -> ([String] -> a -> b) -> AttrSet -> AttrSet
*/
mapAttrsRecursiveCond =
# A function, given the attribute set the recursion is currently at, determine if to recurse deeper into that attribute set.
cond:
# A function, given a list of attribute names and a value, returns a new value.
f:
# Attribute set to recursively map over.
set:
let
recurse = path:
let
g =
name: value:
if isAttrs value && cond value
then recurse (path ++ [name]) value
else f (path ++ [name]) value;
in mapAttrs g;
in recurse [] set;
/* Generate an attribute set by mapping a function over a list of
attribute names.
Example:
genAttrs [ "foo" "bar" ] (name: "x_" + name)
=> { foo = "x_foo"; bar = "x_bar"; }
Type:
genAttrs :: [ String ] -> (String -> Any) -> AttrSet
*/
genAttrs =
# Names of values in the resulting attribute set.
names:
# A function, given the name of the attribute, returns the attribute's value.
f:
listToAttrs (map (n: nameValuePair n (f n)) names);
/* Check whether the argument is a derivation. Any set with
`{ type = "derivation"; }` counts as a derivation.
Example:
nixpkgs = import <nixpkgs> {}
isDerivation nixpkgs.ruby
=> true
isDerivation "foobar"
=> false
Type:
isDerivation :: Any -> Bool
*/
isDerivation =
# Value to check.
value: value.type or null == "derivation";
/* Converts a store path to a fake derivation.
Type:
toDerivation :: Path -> Derivation
*/
toDerivation =
# A store path to convert to a derivation.
path:
let
path' = builtins.storePath path;
res =
{ type = "derivation";
name = sanitizeDerivationName (builtins.substring 33 (-1) (baseNameOf path'));
outPath = path';
outputs = [ "out" ];
out = res;
outputName = "out";
};
in res;
/* If `cond` is true, return the attribute set `as`,
otherwise an empty attribute set.
Example:
optionalAttrs (true) { my = "set"; }
=> { my = "set"; }
optionalAttrs (false) { my = "set"; }
=> { }
Type:
optionalAttrs :: Bool -> AttrSet -> AttrSet
*/
optionalAttrs =
# Condition under which the `as` attribute set is returned.
cond:
# The attribute set to return if `cond` is `true`.
as:
if cond then as else {};
/* Merge sets of attributes and use the function `f` to merge attributes
values.
Example:
zipAttrsWithNames ["a"] (name: vs: vs) [{a = "x";} {a = "y"; b = "z";}]
=> { a = ["x" "y"]; }
Type:
zipAttrsWithNames :: [ String ] -> (String -> [ Any ] -> Any) -> [ AttrSet ] -> AttrSet
*/
zipAttrsWithNames =
# List of attribute names to zip.
names:
# A function, accepts an attribute name, all the values, and returns a combined value.
f:
# List of values from the list of attribute sets.
sets:
listToAttrs (map (name: {
inherit name;
value = f name (catAttrs name sets);
}) names);
/* Merge sets of attributes and use the function f to merge attribute values.
Like `lib.attrsets.zipAttrsWithNames` with all key names are passed for `names`.
Implementation note: Common names appear multiple times in the list of
names, hopefully this does not affect the system because the maximal
laziness avoid computing twice the same expression and `listToAttrs` does
not care about duplicated attribute names.
Example:
zipAttrsWith (name: values: values) [{a = "x";} {a = "y"; b = "z";}]
=> { a = ["x" "y"]; b = ["z"]; }
Type:
zipAttrsWith :: (String -> [ Any ] -> Any) -> [ AttrSet ] -> AttrSet
*/
zipAttrsWith =
builtins.zipAttrsWith or (f: sets: zipAttrsWithNames (concatMap attrNames sets) f sets);
/* Merge sets of attributes and combine each attribute value in to a list.
Like `lib.attrsets.zipAttrsWith` with `(name: values: values)` as the function.
Example:
zipAttrs [{a = "x";} {a = "y"; b = "z";}]
=> { a = ["x" "y"]; b = ["z"]; }
Type:
zipAttrs :: [ AttrSet ] -> AttrSet
*/
zipAttrs =
# List of attribute sets to zip together.
sets:
zipAttrsWith (name: values: values) sets;
/* Does the same as the update operator '//' except that attributes are
merged until the given predicate is verified. The predicate should
accept 3 arguments which are the path to reach the attribute, a part of
the first attribute set and a part of the second attribute set. When
the predicate is satisfied, the value of the first attribute set is
replaced by the value of the second attribute set.
Example:
recursiveUpdateUntil (path: l: r: path == ["foo"]) {
# first attribute set
foo.bar = 1;
foo.baz = 2;
bar = 3;
} {
#second attribute set
foo.bar = 1;
foo.quz = 2;
baz = 4;
}
=> {
foo.bar = 1; # 'foo.*' from the second set
foo.quz = 2; #
bar = 3; # 'bar' from the first set
baz = 4; # 'baz' from the second set
}
Type:
recursiveUpdateUntil :: ( [ String ] -> AttrSet -> AttrSet -> Bool ) -> AttrSet -> AttrSet -> AttrSet
*/
recursiveUpdateUntil =
# Predicate, taking the path to the current attribute as a list of strings for attribute names, and the two values at that path from the original arguments.
pred:
# Left attribute set of the merge.
lhs:
# Right attribute set of the merge.
rhs:
let f = attrPath:
zipAttrsWith (n: values:
let here = attrPath ++ [n]; in
if length values == 1
|| pred here (elemAt values 1) (head values) then
head values
else
f here values
);
in f [] [rhs lhs];
/* A recursive variant of the update operator ‘//’. The recursion
stops when one of the attribute values is not an attribute set,
in which case the right hand side value takes precedence over the
left hand side value.
Example:
recursiveUpdate {
boot.loader.grub.enable = true;
boot.loader.grub.device = "/dev/hda";
} {
boot.loader.grub.device = "";
}
returns: {
boot.loader.grub.enable = true;
boot.loader.grub.device = "";
}
Type:
recursiveUpdate :: AttrSet -> AttrSet -> AttrSet
*/
recursiveUpdate =
# Left attribute set of the merge.
lhs:
# Right attribute set of the merge.
rhs:
recursiveUpdateUntil (path: lhs: rhs: !(isAttrs lhs && isAttrs rhs)) lhs rhs;
/* Returns true if the pattern is contained in the set. False otherwise.
Example:
matchAttrs { cpu = {}; } { cpu = { bits = 64; }; }
=> true
Type:
matchAttrs :: AttrSet -> AttrSet -> Bool
*/
matchAttrs =
# Attribute set structure to match
pattern:
# Attribute set to find patterns in
attrs:
assert isAttrs pattern;
all id (attrValues (zipAttrsWithNames (attrNames pattern) (n: values:
let pat = head values; val = elemAt values 1; in
if length values == 1 then false
else if isAttrs pat then isAttrs val && matchAttrs pat val
else pat == val
) [pattern attrs]));
/* Override only the attributes that are already present in the old set
useful for deep-overriding.
Example:
overrideExisting {} { a = 1; }
=> {}
overrideExisting { b = 2; } { a = 1; }
=> { b = 2; }
overrideExisting { a = 3; b = 2; } { a = 1; }
=> { a = 1; b = 2; }
Type:
overrideExisting :: AttrSet -> AttrSet -> AttrSet
*/
overrideExisting =
# Original attribute set
old:
# Attribute set with attributes to override in `old`.
new:
mapAttrs (name: value: new.${name} or value) old;
/* Turns a list of strings into a human-readable description of those
strings represented as an attribute path. The result of this function is
not intended to be machine-readable.
Create a new attribute set with `value` set at the nested attribute location specified in `attrPath`.
Example:
showAttrPath [ "foo" "10" "bar" ]
=> "foo.\"10\".bar"
showAttrPath []
=> "<root attribute path>"
Type:
showAttrPath :: [String] -> String
*/
showAttrPath =
# Attribute path to render to a string
path:
if path == [] then "<root attribute path>"
else concatMapStringsSep "." escapeNixIdentifier path;
/* Get a package output.
If no output is found, fallback to `.out` and then to the default.
Example:
getOutput "dev" pkgs.openssl
=> "/nix/store/9rz8gxhzf8sw4kf2j2f1grr49w8zx5vj-openssl-1.0.1r-dev"
Type:
getOutput :: String -> Derivation -> String
*/
getOutput = output: pkg:
if ! pkg ? outputSpecified || ! pkg.outputSpecified
then pkg.${output} or pkg.out or pkg
else pkg;
/* Get a package's `bin` output.
If the output does not exist, fallback to `.out` and then to the default.
Example:
getBin pkgs.openssl
=> "/nix/store/9rz8gxhzf8sw4kf2j2f1grr49w8zx5vj-openssl-1.0.1r"
Type:
getBin :: Derivation -> String
*/
getBin = getOutput "bin";
/* Get a package's `lib` output.
If the output does not exist, fallback to `.out` and then to the default.
Example:
getLib pkgs.openssl
=> "/nix/store/9rz8gxhzf8sw4kf2j2f1grr49w8zx5vj-openssl-1.0.1r-lib"
Type:
getLib :: Derivation -> String
*/
getLib = getOutput "lib";
/* Get a package's `dev` output.
If the output does not exist, fallback to `.out` and then to the default.
Example:
getDev pkgs.openssl
=> "/nix/store/9rz8gxhzf8sw4kf2j2f1grr49w8zx5vj-openssl-1.0.1r-dev"
Type:
getDev :: Derivation -> String
*/
getDev = getOutput "dev";
/* Get a package's `man` output.
If the output does not exist, fallback to `.out` and then to the default.
Example:
getMan pkgs.openssl
=> "/nix/store/9rz8gxhzf8sw4kf2j2f1grr49w8zx5vj-openssl-1.0.1r-man"
Type:
getMan :: Derivation -> String
*/
getMan = getOutput "man";
/* Pick the outputs of packages to place in `buildInputs`
Type: chooseDevOutputs :: [Derivation] -> [String]
*/
chooseDevOutputs =
# List of packages to pick `dev` outputs from
drvs:
builtins.map getDev drvs;
/* Make various Nix tools consider the contents of the resulting
attribute set when looking for what to build, find, etc.
This function only affects a single attribute set; it does not
apply itself recursively for nested attribute sets.
Example:
{ pkgs ? import <nixpkgs> {} }:
{
myTools = pkgs.lib.recurseIntoAttrs {
inherit (pkgs) hello figlet;
};
}
Type:
recurseIntoAttrs :: AttrSet -> AttrSet
*/
recurseIntoAttrs =
# An attribute set to scan for derivations.
attrs:
attrs // { recurseForDerivations = true; };
/* Undo the effect of recurseIntoAttrs.
Type:
dontRecurseIntoAttrs :: AttrSet -> AttrSet
*/
dontRecurseIntoAttrs =
# An attribute set to not scan for derivations.
attrs:
attrs // { recurseForDerivations = false; };
/* `unionOfDisjoint x y` is equal to `x // y // z` where the
attrnames in `z` are the intersection of the attrnames in `x` and
`y`, and all values `assert` with an error message. This
operator is commutative, unlike (//).
Type: unionOfDisjoint :: AttrSet -> AttrSet -> AttrSet
*/
unionOfDisjoint = x: y:
let
intersection = builtins.intersectAttrs x y;
collisions = lib.concatStringsSep " " (builtins.attrNames intersection);
mask = builtins.mapAttrs (name: value: builtins.throw
"unionOfDisjoint: collision on ${name}; complete list: ${collisions}")
intersection;
in
(x // y) // mask;
# DEPRECATED
zipWithNames = zipAttrsWithNames;
# DEPRECATED
zip = builtins.trace
"lib.zip is deprecated, use lib.zipAttrsWith instead" zipAttrsWith;
}