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Date: Wed, 6 Mar 2024 09:22:28 +0900
Message-ID: <CAEPPVa1ipFNWfVrCTHWJAzRa6rYYFtrfUnzGW0UgsgGyinN7DA@mail.gmail.com>
Subject: Re: [PHP-DEV] [Discussion] grapheme cluster for str_split function
To: internals@lists.php.net
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From: youkidearitai@gmail.com (youkidearitai)

Hi, Larry
Hi, Niels

2024=E5=B9=B43=E6=9C=886=E6=97=A5(=E6=B0=B4) 6:47 Niels Dossche <dossche.ni=
els@gmail.com>:
>
> Hi Larry
> Hi Yuya
>
> So first of all, I meant the error handling in cases like these: https://=
github.com/php/php-src/pull/13580/files#diff-b8fe038d9d7539694593978bea5605=
f38dde4bcb6a016865130590e45e23202eR852-R860
> The implementation still returns NULL here, so the signature is still inc=
orrect. Either it should return false to match the other functions, or thro=
w something and not return a value.
>
> On 05/03/2024 18:40, Larry Garfield wrote:
> > On Tue, Mar 5, 2024, at 7:25 AM, youkidearitai wrote:
> >> 2024=E5=B9=B43=E6=9C=885=E6=97=A5(=E7=81=AB) 5:52 Niels Dossche <dossc=
he.niels@gmail.com>:
> >>>
> >>> Hi Yuya
> >>>
> >>> This sounds useful.
> >>>
> >>> I do have a question about the function signature:
> >>> function grapheme_str_split(string $string, int $length =3D 1): array=
 {}
> >>>
> >>> This always returns an array.
> >>> However, looking at your PR it seems you return NULL on failure, but =
the return type in the signature isn't nullable.
> >>> Also, from a quick look, it seems other functions return false instea=
d of null on failure. So perhaps the return type should be array|false.
> >>>
> >>> What do you think? :)
> >>>
> >>> Kind regards
> >>> Niels
> >>>
> >>> On 03/03/2024 00:21, youkidearitai wrote:
> >>>> Hi, Internals
> >>>>
> >>>> I noticed PHP does not have grapheme cluster for str_split function.=
,
> >>>> Until now, you had to use the PCRE function's \X.
> >>>>
> >>>> Therefore, I try create `grapheme_str_split` function.
> >>>> https://github.com/php/php-src/pull/13580
> >>>> It is possible to convert array per emoji and variation selectors us=
ing ICU.
> >>>>
> >>>> If it's fine, I'll create an RFC.
> >>>>
> >>>> Regards
> >>>> Yuya
> >>>>
> >>
> >> Hi, Niels
> >>
> >> Thank you for your comment.
> >> Indeed, returns false is make sense.
> >>
> >> Therefore, I changed to returns false when invalid UTF-8 strings.
> >>
> >> Regards
> >> Yuya
> >
> > Many legacy functions return false on error, but that is widely regarde=
d as bad design.  Please do not continue bad design.
>
> I agree that returning false on error isn't ideal for exceptional cases, =
that's what exceptions are for.
> Looking at the other grapheme functions makes me wonder though how consis=
tent this would be, especially w.r.t. intl_get_error_*() and intl_error_nam=
e().
>
> >
> > Right now, the best "standard" error handling mechanism available is ex=
ceptions.  false (or null) can very easily lead to incorrectly using that v=
alue as though it were valid, when it's not, which will sometimes cause a f=
atal error and sometimes cause a security leak.
> >
> > If the input value cannot be logically processed, that's an exception. =
 (Or Error, perhaps.)
> >
> > --Larry Garfield
>
> Kind regards
> Niels

Thank you so much for advice.
Indeed, This current grapheme* functions seems inconsistent.

Therefore, it's one thing when returns null, throws any exception.
Shall we do so just for the grapheme_str_split function?

Regards
Yuya

--=20
---------------------------
Yuya Hamada (tekimen)
- https://tekitoh-memdhoi.info
- https://github.com/youkidearitai
-----------------------------