removePrefix
lib.removePrefix
Docs pulled from | This Revision | 16 minutes ago
Return 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: str:
# Before 23.05, paths would be copied to the store before converting them
# to strings and comparing. This was surprising and confusing.
warnIf (isPath prefix)
''
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.
This behavior is deprecated and will throw an error in the future.''
(
let
preLen = stringLength prefix;
in
if substring 0 preLen str == prefix then
# -1 will take the string until the end
substring preLen (-1) str
else
str
);