fediversity.eu/lib.nix

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Nix
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2024-10-11 21:38:57 +02:00
{ lib }:
rec {
/**
Create a URL-safe slug from any string
*/
slug = str:
let
# Replace non-alphanumeric characters with hyphens
replaced = join ""
(
builtins.map
(c:
if (c >= "a" && c <= "z") || (c >= "0" && c <= "9")
then c
else "-"
)
(with lib; stringToCharacters (toLower str)));
# Remove leading and trailing hyphens
trimHyphens = s:
let
matched = builtins.match "(-*)([^-].*[^-]|[^-])(-*)" s;
in
with lib; optionalString (!isNull matched) (builtins.elemAt matched 1);
collapseHyphens = s:
let
result = builtins.replaceStrings [ "--" ] [ "-" ] s;
in
if result == s then s else collapseHyphens result;
in
trimHyphens (collapseHyphens replaced);
join = lib.concatStringsSep;
splitLines = s: with builtins; filter (x: !isList x) (split "\n" s);
indent = prefix: s:
join "\n" (map (x: if x == "" then x else "${prefix}${x}") (splitLines s));
}