[wg-camlp4] Changes to the parsetree

[Leo White]

>>   - So far, a begin/end pair can always be replaced by normal parentheses.
>>     The "keyword" rules do not allow it so far - when we have
>>     begin [@foo] ... end, why not also allow ([@foo] ...) ?
>
> This (and also (%foo ...)) used to be recognized, but there has been some resistance to it.  I don't have a strong
> opinion on this topic and it will always be possible to add more syntax if the current one turns out to be inconvenient
> in some cases.

Note that my objection was to "(% foo ...)", I have no problem with
"([@foo ...] ...)".