214d4fb73c
For example, this allows writing nix.package = /nix/store/786mlvhd17xvcp2r4jmmay6jj4wj6b7f-nix-1.10pre4206_896428c; Also, document types.package in the manual.
227 lines
6.9 KiB
Nix
227 lines
6.9 KiB
Nix
/* String manipulation functions. */
|
||
|
||
let lib = import ./default.nix;
|
||
|
||
inherit (builtins) length;
|
||
|
||
in
|
||
|
||
rec {
|
||
|
||
inherit (builtins) stringLength substring head tail isString replaceStrings;
|
||
|
||
|
||
# Concatenate a list of strings.
|
||
concatStrings =
|
||
if builtins ? concatStringsSep then
|
||
builtins.concatStringsSep ""
|
||
else
|
||
lib.foldl' (x: y: x + y) "";
|
||
|
||
|
||
# Map a function over a list and concatenate the resulting strings.
|
||
concatMapStrings = f: list: concatStrings (map f list);
|
||
concatImapStrings = f: list: concatStrings (lib.imap f list);
|
||
|
||
|
||
# Place an element between each element of a list, e.g.,
|
||
# `intersperse "," ["a" "b" "c"]' returns ["a" "," "b" "," "c"].
|
||
intersperse = separator: list:
|
||
if list == [] || length list == 1
|
||
then list
|
||
else tail (lib.concatMap (x: [separator x]) list);
|
||
|
||
|
||
# Concatenate a list of strings with a separator between each element, e.g.
|
||
# concatStringsSep " " ["foo" "bar" "xyzzy"] == "foo bar xyzzy"
|
||
concatStringsSep = builtins.concatStringsSep or (separator: list:
|
||
concatStrings (intersperse separator list));
|
||
|
||
concatMapStringsSep = sep: f: list: concatStringsSep sep (map f list);
|
||
concatImapStringsSep = sep: f: list: concatStringsSep sep (lib.imap f list);
|
||
|
||
|
||
# Construct a Unix-style search path consisting of each `subDir"
|
||
# directory of the given list of packages. For example,
|
||
# `makeSearchPath "bin" ["x" "y" "z"]' returns "x/bin:y/bin:z/bin".
|
||
makeSearchPath = subDir: packages:
|
||
concatStringsSep ":" (map (path: path + "/" + subDir) packages);
|
||
|
||
|
||
# Construct a library search path (such as RPATH) containing the
|
||
# libraries for a set of packages, e.g. "${pkg1}/lib:${pkg2}/lib:...".
|
||
makeLibraryPath = makeSearchPath "lib";
|
||
|
||
|
||
# Idem for Perl search paths.
|
||
makePerlPath = makeSearchPath "lib/perl5/site_perl";
|
||
|
||
|
||
# Dependening on the boolean `cond', return either the given string
|
||
# or the empty string.
|
||
optionalString = cond: string: if cond then string else "";
|
||
|
||
|
||
# Determine whether a string has given prefix/suffix.
|
||
hasPrefix = pref: str:
|
||
substring 0 (stringLength pref) str == pref;
|
||
hasSuffix = suff: str:
|
||
let
|
||
lenStr = stringLength str;
|
||
lenSuff = stringLength suff;
|
||
in lenStr >= lenSuff &&
|
||
substring (lenStr - lenSuff) lenStr str == suff;
|
||
|
||
|
||
# Convert a string to a list of characters (i.e. singleton strings).
|
||
# For instance, "abc" becomes ["a" "b" "c"]. This allows you to,
|
||
# e.g., map a function over each character. However, note that this
|
||
# will likely be horribly inefficient; Nix is not a general purpose
|
||
# programming language. Complex string manipulations should, if
|
||
# appropriate, be done in a derivation.
|
||
stringToCharacters = s:
|
||
map (p: substring p 1 s) (lib.range 0 (stringLength s - 1));
|
||
|
||
|
||
# Manipulate a string charactter by character and replace them by
|
||
# strings before concatenating the results.
|
||
stringAsChars = f: s:
|
||
concatStrings (
|
||
map f (stringToCharacters s)
|
||
);
|
||
|
||
|
||
# Escape occurrence of the elements of ‘list’ in ‘string’ by
|
||
# prefixing it with a backslash. For example, ‘escape ["(" ")"]
|
||
# "(foo)"’ returns the string ‘\(foo\)’.
|
||
escape = list: replaceChars list (map (c: "\\${c}") list);
|
||
|
||
|
||
# Escape all characters that have special meaning in the Bourne shell.
|
||
escapeShellArg = lib.escape (stringToCharacters "\\ ';$`()|<>\t*[]");
|
||
|
||
|
||
# Obsolete - use replaceStrings instead.
|
||
replaceChars = builtins.replaceStrings or (
|
||
del: new: s:
|
||
let
|
||
substList = lib.zipLists del new;
|
||
subst = c:
|
||
let found = lib.findFirst (sub: sub.fst == c) null substList; in
|
||
if found == null then
|
||
c
|
||
else
|
||
found.snd;
|
||
in
|
||
stringAsChars subst s);
|
||
|
||
|
||
# Case conversion utilities.
|
||
lowerChars = stringToCharacters "abcdefghijklmnopqrstuvwxyz";
|
||
upperChars = stringToCharacters "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
|
||
toLower = replaceChars upperChars lowerChars;
|
||
toUpper = replaceChars lowerChars upperChars;
|
||
|
||
|
||
# Appends string context from another string.
|
||
addContextFrom = a: b: substring 0 0 a + b;
|
||
|
||
|
||
# Cut a string with a separator and produces a list of strings which
|
||
# were separated by this separator; e.g., `splitString "."
|
||
# "foo.bar.baz"' returns ["foo" "bar" "baz"].
|
||
splitString = _sep: _s:
|
||
let
|
||
sep = addContextFrom _s _sep;
|
||
s = addContextFrom _sep _s;
|
||
sepLen = stringLength sep;
|
||
sLen = stringLength s;
|
||
lastSearch = sLen - sepLen;
|
||
startWithSep = startAt:
|
||
substring startAt sepLen s == sep;
|
||
|
||
recurse = index: startAt:
|
||
let cutUntil = i: [(substring startAt (i - startAt) s)]; in
|
||
if index < lastSearch then
|
||
if startWithSep index then
|
||
let restartAt = index + sepLen; in
|
||
cutUntil index ++ recurse restartAt restartAt
|
||
else
|
||
recurse (index + 1) startAt
|
||
else
|
||
cutUntil sLen;
|
||
in
|
||
recurse 0 0;
|
||
|
||
|
||
# return the suffix of the second argument if the first argument match its
|
||
# prefix. e.g.,
|
||
# `removePrefix "foo." "foo.bar.baz"' returns "bar.baz".
|
||
removePrefix = pre: s:
|
||
let
|
||
preLen = stringLength pre;
|
||
sLen = stringLength s;
|
||
in
|
||
if hasPrefix pre s then
|
||
substring preLen (sLen - preLen) s
|
||
else
|
||
s;
|
||
|
||
removeSuffix = suf: s:
|
||
let
|
||
sufLen = stringLength suf;
|
||
sLen = stringLength s;
|
||
in
|
||
if sufLen <= sLen && suf == substring (sLen - sufLen) sufLen s then
|
||
substring 0 (sLen - sufLen) s
|
||
else
|
||
s;
|
||
|
||
# Return true iff string v1 denotes a version older than v2.
|
||
versionOlder = v1: v2: builtins.compareVersions v2 v1 == 1;
|
||
|
||
|
||
# Return true iff string v1 denotes a version equal to or newer than v2.
|
||
versionAtLeast = v1: v2: !versionOlder v1 v2;
|
||
|
||
|
||
# Get the version of the specified derivation, as specified in its
|
||
# ‘name’ attribute.
|
||
getVersion = drv: (builtins.parseDrvName drv.name).version;
|
||
|
||
|
||
# Extract name with version from URL. Ask for separator which is
|
||
# supposed to start extension.
|
||
nameFromURL = url: sep:
|
||
let
|
||
components = splitString "/" url;
|
||
filename = lib.last components;
|
||
name = builtins.head (splitString sep filename);
|
||
in assert name != filename; name;
|
||
|
||
|
||
# Create an --{enable,disable}-<feat> string that can be passed to
|
||
# standard GNU Autoconf scripts.
|
||
enableFeature = enable: feat: "--${if enable then "enable" else "disable"}-${feat}";
|
||
|
||
|
||
# Create a fixed width string with additional prefix to match
|
||
# required width.
|
||
fixedWidthString = width: filler: str:
|
||
let
|
||
strw = lib.stringLength str;
|
||
reqWidth = width - (lib.stringLength filler);
|
||
in
|
||
assert strw <= width;
|
||
if strw == width then str else filler + fixedWidthString reqWidth filler str;
|
||
|
||
|
||
# Format a number adding leading zeroes up to fixed width.
|
||
fixedWidthNumber = width: n: fixedWidthString width "0" (toString n);
|
||
|
||
|
||
# Check whether a value is a store path.
|
||
isStorePath = x: builtins.substring 0 1 (toString x) == "/" && dirOf (builtins.toPath x) == builtins.storeDir;
|
||
|
||
}
|