Re: m4_pattern_forbid

[Eric Blake]

On 03/17/2015 06:02 PM, Matěj Týč wrote:

> 
> What is interesting: I wanted to point out that it should be more
> appropriate to write m4_pattern_forbid([\bMACRO]) than ...([^MACRO]),
> but I found out that it is not really the true:

The perl code in autom4te splits all words of the input into one word
per line before running the regex.

> 
> cat << EOF | autom4te -l m4sugar
> m4_pattern_forbid([^FOO])
> m4_divert_push(1)dnl
>  FOO1
> FOO2
> hidden FOO3

so all three instances of these FOO match the pattern to be rejected
(after being rewritten as:
FOO1
FOO2
hidden
FOO3
before testing the regex)

> hiddenFOO4

and this does not.

> So maybe getting involved \b is not needed under these circumstances?

The accept/reject patterns operate on each word as if on the line by
themselves, so no need to use \b.

-- 
Eric Blake   eblake redhat com    +1-919-301-3266
Libvirt virtualization library http://libvirt.org

signature.asc
Description: OpenPGP digital signature