Merge pull request #100953 from AtnNn/splitStrings

Implement splitString using builtins.split
This commit is contained in:
Silvan Mosberger 2020-10-20 22:12:52 +02:00 committed by GitHub
commit a2fe9a7abc
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2 changed files with 28 additions and 21 deletions

View file

@ -315,6 +315,16 @@ rec {
*/
escapeNixString = s: escape ["$"] (builtins.toJSON s);
/* Turn a string into an exact regular expression
Type: string -> string
Example:
escapeRegex "[^a-z]*"
=> "\\[\\^a-z]\\*"
*/
escapeRegex = escape (stringToCharacters "\\[{()^$?*+|.");
/* Quotes a string if it can't be used as an identifier directly.
Type: string -> string
@ -386,8 +396,6 @@ rec {
/* Cut a string with a separator and produces a list of strings which
were separated by this separator.
NOTE: this function is not performant and should never be used.
Example:
splitString "." "foo.bar.baz"
=> [ "foo" "bar" "baz" ]
@ -396,26 +404,11 @@ rec {
*/
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;
sep = builtins.unsafeDiscardStringContext _sep;
s = builtins.unsafeDiscardStringContext _s;
splits = builtins.filter builtins.isString (builtins.split (escapeRegex sep) s);
in
recurse 0 0;
map (v: addContextFrom _sep (addContextFrom _s v)) splits;
/* Return a string without the specified prefix, if the prefix matches.

View file

@ -154,6 +154,20 @@ runTests {
expected = [ "2001" "db8" "0" "0042" "" "8a2e" "370" "" ];
};
testSplitStringsRegex = {
expr = strings.splitString "\\[{}]()^$?*+|." "A\\[{}]()^$?*+|.B";
expected = [ "A" "B" ];
};
testSplitStringsDerivation = {
expr = take 3 (strings.splitString "/" (derivation {
name = "name";
builder = "builder";
system = "system";
}));
expected = ["" "nix" "store"];
};
testSplitVersionSingle = {
expr = versions.splitVersion "1";
expected = [ "1" ];