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Date: Wed, 6 Mar 2024 09:37:18 +0900
Message-ID: <CAEPPVa15nvhqzuxM0EhC8GX0rKK7episAJ124cfb9j0kphCGKQ@mail.gmail.com>
Subject: Re: [PHP-DEV] [Discussion] grapheme cluster for str_split function
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From: youkidearitai@gmail.com (youkidearitai)

2024=E5=B9=B43=E6=9C=886=E6=97=A5(=E6=B0=B4) 9:22 youkidearitai <youkideari=
tai@gmail.com>:
>
> Hi, Larry
> Hi, Niels
>
> 2024=E5=B9=B43=E6=9C=886=E6=97=A5(=E6=B0=B4) 6:47 Niels Dossche <dossche.=
niels@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-b8fe038d9d7539694593978bea56=
05f38dde4bcb6a016865130590e45e23202eR852-R860
> > The implementation still returns NULL here, so the signature is still i=
ncorrect. Either it should return false to match the other functions, or th=
row 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 <dos=
sche.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): arr=
ay {}
> > >>>
> > >>> This always returns an array.
> > >>> However, looking at your PR it seems you return NULL on failure, bu=
t the return type in the signature isn't nullable.
> > >>> Also, from a quick look, it seems other functions return false inst=
ead 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 functio=
n.,
> > >>>> 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 =
using 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 regar=
ded 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 cons=
istent this would be, especially w.r.t. intl_get_error_*() and intl_error_n=
ame().
> >
> > >
> > > Right now, the best "standard" error handling mechanism available is =
exceptions.  false (or null) can very easily lead to incorrectly using that=
 value as though it were valid, when it's not, which will sometimes cause a=
 fatal 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
>
> --
> ---------------------------
> Yuya Hamada (tekimen)
> - https://tekitoh-memdhoi.info
> - https://github.com/youkidearitai
> -----------------------------

Ah, If throws exception when intl_error*, is required other an RFC?
If we make grapheme_str_split's signature is below (include null):

```
function grapheme_str_split(string $string, int $length =3D 1): array|null =
{}
```

For now, I change signature to `array|null`.

Regards
Yuya


--=20
---------------------------
Yuya Hamada (tekimen)
- https://tekitoh-memdhoi.info
- https://github.com/youkidearitai
-----------------------------