nixpkgs/lib/filesystem.nix
2022-10-26 15:10:47 +02:00

80 lines
2.3 KiB
Nix

# Functions for copying sources to the Nix store.
{ lib }:
let
inherit (lib.strings)
hasPrefix
;
in
{
/*
A map of all haskell packages defined in the given path,
identified by having a cabal file with the same name as the
directory itself.
Type: Path -> Map String Path
*/
haskellPathsInDir =
# The directory within to search
root:
let # Files in the root
root-files = builtins.attrNames (builtins.readDir root);
# Files with their full paths
root-files-with-paths =
map (file:
{ name = file; value = root + "/${file}"; }
) root-files;
# Subdirectories of the root with a cabal file.
cabal-subdirs =
builtins.filter ({ name, value }:
builtins.pathExists (value + "/${name}.cabal")
) root-files-with-paths;
in builtins.listToAttrs cabal-subdirs;
/*
Find the first directory containing a file matching 'pattern'
upward from a given 'file'.
Returns 'null' if no directories contain a file matching 'pattern'.
Type: RegExp -> Path -> Nullable { path : Path; matches : [ MatchResults ]; }
*/
locateDominatingFile =
# The pattern to search for
pattern:
# The file to start searching upward from
file:
let go = path:
let files = builtins.attrNames (builtins.readDir path);
matches = builtins.filter (match: match != null)
(map (builtins.match pattern) files);
in
if builtins.length matches != 0
then { inherit path matches; }
else if path == /.
then null
else go (dirOf path);
parent = dirOf file;
isDir =
let base = baseNameOf file;
type = (builtins.readDir parent).${base} or null;
in file == /. || type == "directory";
in go (if isDir then file else parent);
/*
Given a directory, return a flattened list of all files within it recursively.
Type: Path -> [ Path ]
*/
listFilesRecursive =
# The path to recursively list
dir:
lib.flatten (lib.mapAttrsToList (name: type:
if type == "directory" then
lib.filesystem.listFilesRecursive (dir + "/${name}")
else
dir + "/${name}"
) (builtins.readDir dir));
}