-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Hello Gary,
According to Gary V. Vaughan on 5/31/2007 5:19 AM: >> Meanwhile, m4's format builtin, for the past 17 years, has handled %c as >> a conversion from integer to character (with ASCII, format(%c,9) results >> in TAB, [[...]] > > Gratuitously breaking 17 years of accumulated GNU m4 input seems like a > bad idea to me. What do other m4 implementations do? format is a GNU extension. Not even BSD m4 provides this extension. There is no precedent, which is why I think making format more like printf(1) has merit. >> Any objections to this approach? > > Not if it is only turned on in POSIXLY_CORRECT mode, at least in the > stable branch. But that seems wrong. Since format is a GNU extension, POSIXLY_CORRECT should not affect it. And I have already ensured that the changes I am proposing to the branch do not affect the expansion of existing valid strings; all it does is add new expansions that were previously undocumented and invalid (therefore no one could have been using them), and add warnings on certain expansions that are not compatible with printf(1). > For 2.0, using a posixy approach by default is okay, > provided there is no code in recent autoconf releases that barfs at the > change... For the branch, %c would continue to behave in the old clunky way, only it would now also emit a warning (but not affect exit status, so as not to kill autoconf). And to make sure, we could even do this: if the string looks like an integer, use the old semantics with a warning; otherwise, use the first character of the string, so that it is not until 2.1 where %c can finally fully match printf by always using the first character of the string. However, I think the amount of autoconf code that relies on the old %c syntax is minimal, particularly since it is so confusing because it is currently different than printf(1). Maybe it is also worth improving the command line to add a --warnings=level option that can silence the new warnings, without impacting other warnings? - -- Don't work too hard, make some time for fun as well! Eric Blake [EMAIL PROTECTED] -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.5 (Cygwin) Comment: Public key at home.comcast.net/~ericblake/eblake.gpg Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org iD8DBQFGXsgR84KuGfSFAYARAjUBAKCOh3t2KnzWlRSd062WgB06PW/cCwCfXr75 fYUGT3oZzG1Y1VMu5yOiyu4= =LLdp -----END PGP SIGNATURE----- _______________________________________________ M4-discuss mailing list M4-discuss@gnu.org http://lists.gnu.org/mailman/listinfo/m4-discuss
