anchor.diff:  
     /* Read the contents of a file removing the trailing \n
   
  +     Type: fileContents :: path -> string
  +
        Example:
          $ echo "1.0" > ./version
   
  
positive.code:        optionalString false "some-string"
         => ""
    */
    optionalString = cond: string: if cond then string else "";
  
    /* Determine whether a string has given prefix.
  
       Example:
         hasPrefix "foo" "foobar"
  
negative.code:   /* Manipulate a string character by character and replace them by
       strings before concatenating the results.
  
       Type: stringAsChars :: (string -> string) -> string -> string
  
       Example:
         stringAsChars (x: if x == "a" then "i" else x) "nax"
         => "nix"
    */
    stringAsChars =
      # Function to map over each individual character
      f:
      # Input string
      s: concatStrings (
        map f (stringToCharacters s)
      );
  
    /* Escape occurrence of the elements of `list` in `string` by
       prefixing it with a backslash.
  
       Type: escape :: [string] -> string -> string
  
       Example:
         escape ["(" ")"] "(foo)"
  