diff --git a/website/lib.nix b/website/lib.nix index b1075d4e..f3cb7e4b 100644 --- a/website/lib.nix +++ b/website/lib.nix @@ -1,5 +1,19 @@ { lib }: rec { + /** + Recursively replace occurrences of `from` with `to` within `string` + + Example: + + replaceStringRec "--" "-" "hello-----world" + => "hello-world" + */ + replaceStringsRec = from: to: string: + let + replaced = lib.replaceStrings [ from ] [ to ] string; + in + if replaced == string then string else replaceStringsRec from to replaced; + /** Create a URL-safe slug from any string */ @@ -22,14 +36,30 @@ rec { 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); + trimHyphens (replaceStringsRec "--" "-" replaced); + + squash = replaceStringsRec "\n\n" "\n"; + + /** + Trim trailing spaces and squash non-leading spaces + */ + trim = string: + let + trimLine = line: + with lib; + let + # separate leading spaces from the rest + parts = split "(^ *)" line; + spaces = head (elemAt parts 1); + rest = elemAt parts 2; + # drop trailing spaces + body = head (split " *$" rest); + in + if body == "" then "" else + spaces + replaceStringsRec " " " " body; + in + join "\n" (map trimLine (splitLines string)); join = lib.concatStringsSep;