Re: Manual: Incorrect explanation of /\B/

[Neil R. Ormos]

arnold@skeeve.com wrote:
> Wolfgang Laun wrote:

>> Currently we have this text (in 3.7):

>> Matches the empty string that occurs between
>> two word-constituent characters. For example,
>> /\Brat\B/ matches "crate", but it does not
>> match "dirty rat". "\B" is essentially the
>> opposite of "\y".

>> It should read: [...]

> This text has been unchanged since at least
> 1997. I think it's OK as is.

I respectfully urge reconsideration.  I believe it was my inquiry on the 
help-gawk list that provoked W.L.'s proposal to revise the manual.

The Gawk manual states that \B "[m]atches the empty string that occurs between 
two word-constituent characters," but is silent as to where else \B matches.  

It is not clear from the manual text that \B also matches *outside* of a run of 
word-constituent characters.

A recent man page for grep(1) recites, "\B matches the empty string provided 
it's not at the edge of a word," which seems to be a concise formulation that 
could be reused in Gawk's manual.

(I'm not sure what led me not to connect the dots between grep's man page and 
Gawk's before I inguired on help-gawk.  Nonetheless, to the extent the Gawk 
manual has a tutorial function, I hope the manual's fine tradition of 
explaining how regexp operators work, without expecting that readers arrive 
with /a priori/ knowledge of the behavior of regexps in grep, Perl, or the 
like, may continue.)