On Mon, May 12, 2025 at 09:54:54AM -0500, Nikolaos Chatzikonstantinou wrote: > > $ echo 'eval(1 || (1/0))' | m4-1.4.20 > > 1 > > $ echo 'eval(1 || (1/0))' | m4p > > m4:stdin:1: divide by zero in eval: 1 || (1/0) > > 1 > > > > I have a file where I noted some of these here: > https://codeberg.org/annoyingusername/m4p/src/branch/main/tests/resources/eval_bugs.txt
Useful. The '1 || (0 / 0)' bug was indeed fixed in 1.4.20. '1 || 2 &= 3' still complains about invalid operator, but that's intentional: &= is not a supported operator. But the complaint about '1 || (2 &= 3)') complaining about a missing right parenthesis (instead of a bad operator) is something I hadn't noticed before today, and something still present in 1.4.20. The parser is correctly detecting that the expression is not valid at the point it hits the invalid operator; but perhaps the error message could be improved (by stating that it expects ')' instead of '&=', for example). Writing a parser that handles only good expressions is easy. Writing a parser that provides sane error messages with useful suggestions when the parse fails is hard. Yours may be the first (indirect) bug report against 1.4.20! > PS. I'm tracking feature progress here, > https://codeberg.org/annoyingusername/m4p/wiki/Features and I will note > some of the things you mentioned when I get back home. Another one that is hopefully easy: $ printf 'divert(2)2\ndivert(1)1\n' | m4 1 2 $ printf 'divert(2)2\ndivert(1)1\n' | m4p $ Non-negative diversions are not being dumped automatically at end of input. -- Eric Blake, Principal Software Engineer Red Hat, Inc. Virtualization: qemu.org | libguestfs.org
