Define {builder,fs}.nix for utils.nix

Re-export everything from utils.nix.
This commit is contained in:
William Carroll 2020-09-01 12:16:34 +01:00
parent fb5ec068dd
commit a076027945
3 changed files with 63 additions and 11 deletions

11
utils/builder.nix Normal file
View file

@ -0,0 +1,11 @@
{ pkgs, ... }:
let
inherit (pkgs) writeShellScriptBin;
in {
# Create a derivation that creates an executable shell script named `as` that
# calls the program located at `path`, forwarding all of the arguments.
wrapNonNixProgram = { path, as }: writeShellScriptBin as ''
exec ${path} "$@"
'';
}

View file

@ -1,14 +1,14 @@
{ pkgs, ... }:
args@{ pkgs, ... }:
# Using this as a library to define some common utility functions that I often
# reach for.
{
# A unary function that returns its argument.
identity = x: x;
# This top-level module exposes all of my utility functions for Nix. It should
# be used like:
# ```nix
# inherit (briefcase.utils) fs;
# ```
# Create a derivation that creates an executable shell script named `as` that
# calls the program located at `path`, forwarding all of the arguments.
wrapNonNixProgram = { path, as }: pkgs.writeShellScriptBin as ''
exec ${path} "$@"
'';
let
builder = import ./builder.nix args;
fs = import ./fs.nix args;
in {
inherit builder fs;
}

41
utils/fs.nix Normal file
View file

@ -0,0 +1,41 @@
{ pkgs, ... }:
# `fs` contains utility functions for working with the filesystem.
let
inherit (builtins) attrNames hasAttr map readDir;
inherit (pkgs.lib) filterAttrs;
in {
# Returns a list of all of the regular files in `dir`.
files = dir:
map (name: dir + "/${name}")
(attrNames
(filterAttrs (_: type: type == "regular") (readDir dir)));
# Returns a list of all of the directories in `dir`.
dirs = dir:
map (name: dir + "/${name}")
(attrNames
(filterAttrs (_: type: type == "directory") (readDir dir)));
# Returns a list of paths to all of the `name` files starting at `dir`.
find = name: dir:
if hasAttr name (readDir dir) then
[ (dir + name) ] ++ concatMap findAllDefaultNix (dirs dir)
else
concatMap findAllDefaultNix (dirs dir);
# Looks for `name` in `dir`; if it cannot find it, it checks the parent
# directory.
resolve = name: dir:
if hasAttr name (readDir dir) then
dir + "/${name}"
else
# This prevents the function from infinitely recursing and eventually
# stack overflowing.
if (dirOf dir) == dir then
null
else
resolve name (dirOf dir);
};
}