foldl'
builtins.foldl'
Primop
Docs pulled from | This Revision | 1 day ago
Takes 3 arguments
op, nul, list
Reduce a list by applying a binary operator, from left to right,
e.g. foldl' op nul [x0 x1 x2 ...] = op (op (op nul x0) x1) x2) ....
For example, foldl' (acc: elem: acc + elem) 0 [1 2 3] evaluates
to 6 and foldl' (acc: elem: { "${elem}" = elem; } // acc) {} ["a" "b"] evaluates to { a = "a"; b = "b"; }.
The first argument of op is the accumulator whereas the second
argument is the current element being processed. The return value
of each application of op is evaluated immediately, even for
intermediate values.
This function is not defined in a .nix file. It is likely a builtins function or an alias of a builtins function. builtins functions are predefined functions provided by Nix.
Noogle detected
Detected Type
foldl' :: (a -> b -> a) -> a -> [b] -> a
Implementation
This function is implemented in c++ and is part of the native nix runtime.