Hi FKtPp -- To deal with your last question first, the integerp change dates from XEmacs 20.0, in the mid-1990s. It is a design decision of most modern programming languages that it is good and useful to be able to tell at runtime whether a given object is a character, and thus should be displayed as ?a, ?á, ?گ or ? 南, or whether it is an integer, and thus should be displayed as a numeric value. Of the major languages in current use, C and friends don’t make the distinction, and nor does GNU Emacs Lisp. XEmacs added it because emacs Lisp is already, compared to C, so slow that the performance impact (checking for whether something is an integer vs. a character) doesn’t matter, and because it is very useful for interactive use and for debugging in this *text* editor. Common Lisp, the other big influence on XEmacs, also has this distinction; MacLisp, the Lisp that both GNU Emacs Lisp and Common Lisp are ultimately based on, did not. The Right Way to handle this kind of incompatible integerp usage is to decide “is the code interested in this value as an integer, or as a character?” and, if the latter, to replace #'integerp calls with #'characterp. If it’s very difficult to tell if the writer is treating the value as a character or as an integer, consider #'char-or-char-int-p. The following comment from xsd-regexp.el suggests that it is most interested in characters: ;; ;; The semantics of XSD regexps are defined in terms of Unicode. ;; Non-Unicode characters are not allowed in regular expressions and ;; will not match against the generated regular expressions. A ;; Unicode character means a character in one of the Mule charsets ;; ascii, latin-iso8859-1, mule-unicode-0100-24ff, ;; mule-unicode-2500-33ff, mule-unicode-e000-ffff, eight-bit-control ;; or a character translateable to such a character (i.e a character ;; for which `encode-char’ will return non-nil). If it were interested in *Unicode values*, then yes, integerp would still be appropriate, but there it’s interested in characters. Another hint that the code is interested in the charater value is when they are compared with something with character syntax, e.g. like (eq value ?a) or (memq ?b list). As far as I can see xsd-regexp.el would be fine with characterp wherever integerp is used; if you’ve any questions about other files, get in touch. Best, Aidan Ar an cúigiú lá déag de mí Iúil, scríobh It's me FKtPp ;): -- ‘Tramadol is further fed to cattle […] when working them […] (as draft animals) so that the animals do not get tired quickly. …’ — Angewandte Chemie, Sept 2014, describing the social context of (synthetic) tramadol having been found in Cameroon tree roots. _______________________________________________ XEmacs-Beta mailing list XEmacs-Beta(a)xemacs.org http://lists.xemacs.org/mailman/listinfo/xemacs-beta