cartesianProduct
lib.attrsets.cartesianProduct
Docs pulled from | This Revision | 13 minutes ago
Return the cartesian product of attribute set value combinations.
Inputs
attrsOfLists-
Attribute set with attributes that are lists of values
Type
cartesianProduct :: AttrSet -> [AttrSet]
Examples
lib.attrsets.cartesianProduct usage example
cartesianProduct { a = [ 1 2 ]; b = [ 10 20 ]; }
=> [
{ a = 1; b = 10; }
{ a = 1; b = 20; }
{ a = 2; b = 10; }
{ a = 2; b = 20; }
]
Noogle detected
Implementation
The following is the current implementation of this function.
cartesianProduct =
attrsOfLists:
foldl' (listOfAttrs: attrName:
concatMap (attrs:
map (listValue: attrs // { ${attrName} = listValue; }) attrsOfLists.${attrName}
) listOfAttrs
) [{}] (attrNames attrsOfLists);