tvl-depot/users/sterni/nix/fun/default.nix

60 lines
1 KiB
Nix
Raw Normal View History

{ depot, lib, ... }:
let
inherit (lib)
id
;
# Simple function composition,
# application is right to left.
rl = f1: f2:
(x: f1 (f2 x));
# Compose a list of functions,
# application is right to left.
rls = fs:
builtins.foldl' (fOut: f: lr f fOut) id fs;
# Simple function composition,
# application is left to right.
lr = f1: f2:
(x: f2 (f1 x));
# Compose a list of functions,
# application is left to right
lrs = x: fs:
builtins.foldl' (v: f: f v) x fs;
# Warning: cursed function
#
# Check if a function has an attribute
# set pattern with an ellipsis as its argument.
#
# s/o to puck for discovering that you could use
# builtins.toXML to introspect functions more than
# you should be able to in Nix.
hasEllipsis = f:
builtins.isFunction f &&
builtins.match ".*<attrspat ellipsis=\"1\">.*"
(builtins.toXML f) != null;
in
{
inherit (lib)
fix
flip
const
;
inherit
id
rl
rls
lr
lrs
hasEllipsis
;
}