From seki@sysrap.cs.fujitsu.co.jp Wed Jan 8 10:24:29 1992 Received: from mcsun.EU.net by dkuug.dk via EUnet with SMTP (5.64+/8+bit/IDA-1.2.8) id AA15845; Wed, 8 Jan 92 10:24:29 +0100 Received: by mcsun.EU.net via EUnet; id AA11281 (5.65a/CWI-2.130); Wed, 8 Jan 1992 10:24:34 +0100 Received: from uunet.uu.net (via LOCALHOST.UU.NET) by relay1.UU.NET with SMTP (5.61/UUNET-internet-primary) id AA06210; Wed, 8 Jan 92 04:21:24 -0500 Received: from fai.UUCP by uunet.uu.net with UUCP/RMAIL (queueing-rmail) id 042106.9714; Wed, 8 Jan 1992 04:21:06 EST Received: by fai.fai.com; id AA13732; Wed, 8 Jan 92 01:19:20-1795 Received: from fdm.fujitsu.co.jp (fdm.ARPA) by a50.fujitsu.co.jp (4.12/6.4J.4 *** FUJITSU National Gateway ***) id AA02352; Wed, 8 Jan 92 18:01:14 JST Received: from [133.161.1.9] by fdm.fujitsu.co.jp (5.65/6.4J.6) id AA07232; Wed, 8 Jan 92 18:15:42 +0900 Received: by spad.sysrap.cs.fujitsu.co.jp (/\==/\ Smail3.1.24.1 #24.2) id ; Wed, 8 Jan 92 18:08 JST Date: Wed, 8 Jan 92 18:06:25 JST From: Masahiro SEKIGUCHI Return-Path: Message-Id: <9201080906.AA00641@seki.sysrap.cs.fujitsu.co.jp> To: wg14@dkuug.dk, i18n@dkuug.dk Subject: Re: (SC22WG14.166) Re: support for symbolic character names References: <9201061934.AA16247@dkuug.dk> X-Charset: ASCII X-Char-Esc: 29 > > What is the purpose of these two functions? Or, in other words, > > what kind of application will use them? > The mechanism is to support portability of international C programs. Great. > It is a lowercase-o-with-stroke. If I want to write a portable > program, which tests for this letter, then it is very difficult. O.K. I agree with you on the point ``it is very difficult.'' but, I don't agree the idea of ``a facility to do such a job easier will increase international portability of applications.'' > It depends on the execution character set. In the one I am really > using now (IBM865) it is one value, in ISO8859-1 it is another, > and in MacIntosh it is yet another. And, in my system, there is no such character. My point is following: If an application *must* check whether a character is an o-with-stroke, it *cannot* be internationally portable. With your proposal, you could write a ``pseudo-portable'' program which tests against o-with-stroke like: if (wc == L'\') ... but it will cause an error like "character(s) specified by a symbolic name notation is not avalable." Is this a portable program? Or, with your function version, your could write: if (wc == scntowc("")) ... This version will be compiled successfully in all countries, but will or will not work appropriately... On my system in Japanese locale, scntowc("") will return WEOF, and ``...'' part will never be executed. If this code is used, for example, as a part of menu driver, I will not able to select an item represented by o-with-stroke. My solution to menu drivers is using messaging facility. For example, with XPG3 style messing facility, I can write (This code might look lengthy, but the first three lines can be done at the startup phase.) : item_3_selector = catgets(cd, SET_MENU, MSG_ITEM_3_SELECTOR); mbtowc(NULL, NULL, 0); mbtowc(&item_3_wchar, item_3_selector, strlen(item_3_selector)); if (wc == item_3_wchar) ... In my code, the character wc is compared against is determined by locale, so users can select items by their most natural keys, e.g., for English: E) EXECUTE Q) QUIT ENTER SELECTION: for German: A) AUSFUEHREN B) BEENDEN AUSWAHL ANGEBEN: and you can use o-with-stroke for Danish if you want. >The mechanism is much in line with current documenter software >like TeX or SGML that has such symbolic names for "weird" characters. Yes. We can use such names safely in TeX, because TeX defines its own codeset (and because it supplies public doman fonts. :-) The case is different from C applications.