On 28-Mar-2021, at 23:36, Junio C Hamano <gitster@xxxxxxxxx> wrote:
>
> Atharva Raykar <raykar.ath@xxxxxxxxx> writes:
>
>>>> + "(\\.|[^][)(\\}\\{ ])+"),
>>>
>>> One or more "dot or anything other than SP or parentheses"? But
>>> a dot "." is neither a space or any {bra-ce} letter, so would the
>>> above be equivalent to
>>>
>>> "[^][()\\{\\} \t]+"
>>>
>>> I wonder...
>>
>> A backslash is allowed in scheme identifiers, and I erroneously thought that
>> the first part handles the case for identifiers such as `component\new` or
>> `\"id-with-quotes\"`. (I tested it with a regex engine that behaves differently
>> than the one git is using, my bad.)
>
> Ah, perhaps you didn't have enough backslashes. A half of the
> doubled one before the dot is eaten by the C compiler, so the regexp
> engine is seeing only a single backslash before the dot, which means
> "literally a single dot". If you meant "literally a single
> backslash, followed by any single char", you probably would write 4
> backslashes and a dot---half of the backslashes would be eaten by
> the compiler, so you'd be passing two backslashes and a dot, which
> is probably what you meant.
>
> Having said that, two further points.
>
> - the "anything but whitespaces and various forms of parentheses"
> set would include backslash, so 'component\new' would be taken as
> a single word with "[^][()\\{\\} \t]+", wouldn't it?
>
> - how common is the use of backslashes in identifiers? I am trying
> to see if the additional complexity needed to support them is
> worth the benefit.
I have refined the regex, and now it is much simpler and does all of what
I want it to:
"([^][)(}{[:space:]])+"
I did not have to escape the various parentheses, so I avoided the need to
handle backslashes separately. The "\\t" was causing problems as well because
it took it as a '\' followed by a 't' (Thanks to j416 on #git-devel for
helping me out on this).
>> Yes, this is exactly what I was trying to express. All words should be
>> delimited by either whitespace or a parenthesis, and all other special
>> characters should be accepted as part of the word.
>
> That sentence after "All words should be..." would be a good comment
> to replace what you wrote in the original, then ;-).
Yes, that should make it a lot more clear.
