removePrefix
lib.strings.removePrefix
Docs pulled from | This Revision | 24 minutes ago
Nixpkgs manual
Returns a string without the specified prefix, if the prefix matches.
Inputs
prefix- Prefix to remove if it matches
str- Input string
Type
removePrefix :: String -> String -> String
Examples
lib.strings.removePrefix usage example
removePrefix "foo." "foo.bar.baz"
=> "bar.baz"
removePrefix "xxx" "foo.bar.baz"
=> "foo.bar.baz"
Noogle detected
Implementation
The following is the current implementation of this function.
removePrefix =
prefix:
let
preLen = stringLength prefix;
in
if isPath prefix then
# Before 23.05, paths would be copied to the store before converting them
# to strings and comparing. This was surprising and confusing.
throw ''
lib.strings.removePrefix: The first argument (${toString prefix}) is a path value, but only strings are supported.
There is almost certainly a bug in the calling code, since this function never removes any prefix in such a case.
This function also copies the path to the Nix store, which may not be what you want.''
else
str:
if substring 0 preLen str == prefix then
# -1 will take the string until the end
substring preLen (-1) str
else
str;