lib.attrsets.getAttrFromPath

Like attrByPath, but without a default value. If it doesn't find the path it will throw an error.

Nix has an attribute selection operator which is sufficient for such queries, as long as the number of attributes is static. For example:

x.a.b == getAttrByPath ["a" "b"] x
# and
x.${f p}."example.com" == getAttrByPath [ (f p) "example.com" ] x

Inputs

attrPath

A list of strings representing the attribute path to get from set

set

The nested attribute set to find the value in.

Type

getAttrFromPath :: [String] -> AttrSet -> Any

Examples

x = { a = { b = 3; }; }
getAttrFromPath ["a" "b"] x
=> 3
getAttrFromPath ["z" "z"] x
=> error: cannot find attribute `z.z'

Noogle detected

• lib.getAttrFromPath

getAttrFromPath =
    attrPath:
    set:
    attrByPath attrPath (abort ("cannot find attribute '" + concatStringsSep "." attrPath + "'")) set;