anchor.diff:  
   
     /* This function recursively removes all derivation attributes from
  -     `x' except for the `name' attribute.  This is to make the
  -     generation of `options.xml' much more efficient: the XML
  -     representation of derivations is very large (on the order of
  -     megabytes) and is not actually used by the manual generator. */
  +     `x` except for the `name` attribute.
  +
  +     This is to make the generation of `options.xml` much more
  +     efficient: the XML representation of derivations is very large
  +     (on the order of megabytes) and is not actually used by the
  +     manual generator.
  +  */
     scrubOptionValue = x:
       if isDerivation x then
         { type = "derivation"; drvPath = x.name; outPath = x.name; name = x.name; }
  
positive.code:     else x;
  
  
    /* For use in the ‘example’ option attribute.  It causes the given
       text to be included verbatim in documentation.  This is necessary
       for example values that are not simple values, e.g.,
       functions. */
    literalExample = text: { _type = "literalExample"; inherit text; };
  
  
    /* Helper functions. */
  
    # Convert an option, described as a list of the option parts in to a
    # safe, human readable version. ie:
    #
    # (showOption ["foo" "bar" "baz"]) == "foo.bar.baz"
    # (showOption ["foo" "bar.baz" "tux"]) == "foo.\"bar.baz\".tux"
    showOption = parts: let
      escapeOptionPart = part:
        let
  
negative.code:       else
          val) (head defs).value defs;
  
    /* Extracts values of all "value" keys of the given list.
  
       Type: getValues :: [ { value :: a } ] -> [a]
  
       Example:
         getValues [ { value = 1; } { value = 2; } ] // => [ 1 2 ]
         getValues [ ]                               // => [ ]
    */
    getValues = map (x: x.value);
  
    /* Extracts values of all "file" keys of the given list
  
       Type: getFiles :: [ { file :: a } ] -> [a]
  
       Example:
         getFiles [ { file = "file1"; } { file = "file2"; } ] // => [ "file1" "file2" ]
         getFiles [ ]                                         // => [ ]
    */
    getFiles = map (x: x.file);
  
    # Generate documentation template from the list of option declaration like
  