diff options
Diffstat (limited to 'lib/strings.nix')
| -rw-r--r-- | lib/strings.nix | 20 |
1 files changed, 20 insertions, 0 deletions
diff --git a/lib/strings.nix b/lib/strings.nix index 4d7fa1e774d..48420a36781 100644 --- a/lib/strings.nix +++ b/lib/strings.nix @@ -236,6 +236,26 @@ rec { in lenContent >= lenSuffix && substring (lenContent - lenSuffix) lenContent content == suffix; + /* Determine whether a string contains the given infix + + Type: hasInfix :: string -> string -> bool + + Example: + hasInfix "bc" "abcd" + => true + hasInfix "ab" "abcd" + => true + hasInfix "cd" "abcd" + => true + hasInfix "foo" "abcd" + => false + */ + hasInfix = infix: content: + let + drop = x: substring 1 (stringLength x) x; + in hasPrefix infix content + || content != "" && hasInfix infix (drop content); + /* Convert a string to a list of characters (i.e. singleton strings). This allows you to, e.g., map a function over each character. However, note that this will likely be horribly inefficient; Nix is not a |