diff options
Diffstat (limited to 'pkgs/lib/strings.nix')
| -rw-r--r-- | pkgs/lib/strings.nix | 16 |
1 files changed, 13 insertions, 3 deletions
diff --git a/pkgs/lib/strings.nix b/pkgs/lib/strings.nix index 071bb2c995b3..4bd7a5bebde3 100644 --- a/pkgs/lib/strings.nix +++ b/pkgs/lib/strings.nix @@ -2,12 +2,12 @@ let lib = import ./default.nix; -inherit (builtins) add sub lessThan; +inherit (builtins) add sub lessThan length; in rec { - inherit (builtins) stringLength substring head tail lessThan sub; + inherit (builtins) stringLength substring head tail; # Concatenate a list of strings. @@ -22,7 +22,7 @@ rec { # Place an element between each element of a list, e.g., # `intersperse "," ["a" "b" "c"]' returns ["a" "," "b" "," "c"]. intersperse = separator: list: - if list == [] || tail list == [] + if list == [] || length list == 1 then list else [(head list) separator] ++ (intersperse separator (tail list)); @@ -155,4 +155,14 @@ rec { # Return true iff string v1 denotes a version older than v2. versionOlder = v1: v2: builtins.compareVersions v2 v1 == 1; + # 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 ! eqStrings name filename; + name; + } |