Re: [PHP-DEV] First time contributor (DateTime::setDate PR)

[Derick Rethans]

On Tue, 2 Apr 2024, Bilge wrote:

> On 02/04/2024 14:14, Derick Rethans wrote:
> > 
> > On Sun, 31 Mar 2024, Bilge wrote:
> > 
> > > About the PR: I sometimes find it would be useful to only update 
> > > part of the date. The PR makes all parameters to 
> > > DateTime(Immutable)::setDate 
> > >  
> > > optional in a backwards-compatible manner such that we can elect 
> > > to update only the day, month, year or any combination of the 
> > > three (thanks, in part, to named parameters). Without this 
> > > modification, we must always specify all of the day, month and 
> > > year parameters to change the date.
> > As I mentioned to you in Room 11, I am not in favour of adhoc API 
> > changes to Date/Time classes. It has now been nearly 18 years since 
> > they were originally introduced, and they indeed could do with an 
> > overhaul.
> > 
> > I have been colllecting ideas in 
> > https://docs.google.com/document/d/1pxPSRbfATKE4TFWw72K3p7ir-02YQbTf3S3SIxOKWsk/edit#heading=h.2jol7kfhmijb
> > 
> > Having different/better modifiers would also be a good thing to talk 
> > about, albeit perhaps on the four mentioned new classes, instead of 
> > adding them to the already existing DateTime and DateTimeImmutable 
> > classes.
> > 
> > In any case, just allowing setDate to be able to just modify the 
> > month is going to introduce confusion, as this will be counter 
> > intuitive:
> > 
> > $dt = new DateTimeImmutable("2024-03-31");
> > $newDt = $dt->setDate( month: 2 );
> > 
> > It is now representing 2024-03-02.
> > 
> > This might be the right answer, but it might also be that the 
> > developer just cared about the month part (and not the 
> > day-of-month), in which case this is a WTF moment.
> > 
> > Picking mofication APIs is not as trivial as it seems, and I would 
> > like to do it *right*.
> > 
> > Feel free to add comments and wishes to the google doc document. In 
> > the near future, I will be writing up an RFC from this.
> 
> Thanks for your reply!
> 
> Indeed, as per your code snippet, this is a WTF moment I had not accounted for
> and confirm the same result with my patch applied. Generally, my expectation
> here would be the month *must* be set to 2, so if the day portion will be
> invalidated by that change, we should either throw an exception or implicitly
> coerce it into range, i.e. (new DateTime("2024-03-31"))->setDate(month: 2); ==
> 2024-02-29.

We can't do that, as it will be inconsistent with:

modify("+1 month")
// (also 2024-03-02)

> However, I suppose this is not the conversation we're having as
> you do not wish to change this API at all, which I respect.

I think what you're actually after here, is a "YearMonth" type, which 
doesn't concern itself with the day-of-month at all. Setting just the 
month should perhaps just reset the day-of-month to 1 instead. ANd 
setting just the year would result in January 1st, as well.

> Regarding your brainstorm document, I can't understand much of it in its
> current state, and as I am not a subject matter expert, I think you will
> receive much better feedback from others.

It isn't particularly organised yet, and... I also haven't made sense of 
all of it yet.

> In particular, I cannot glean which four classes you are referring to 
> in that document. Yet what I do find interesting is the notion of 
> adding setters to DateTimeImmutable. For my particular 
> use-case—producing a collection of dates incrementing by year in a 
> Twig template—a trivial year setter would do just fine, with the 
> significant caveat that it must implement fluent interface, because I 
> need to call it in an expression context (returning a value), not a 
> statement context (executing a void function separately). Not that 
> Twig cannot execute statements, but it just becomes more verbose, 
> cumbersome and less template-like.
> 
> If you were happy for me to add getters and fluent setters for year, 
> I'd be happy to work on that PR, but for month we're back to the same 
> problem outlined in the opening paragraph (and I suppose the same 
> problem occasionally applies to year, if the day happens to be set to 
> the leap day). Otherwise, I'll be happy to read over your RFC when 
> it's ready.

Feel free to add your suggestion (anywhere) in the document, preferrably 
at the bottom :-)

I can envision that we'll have some actual setters and getters, beyond 
just add, sub, and modify (which is really powerful).

But what is important to understand is rather *why* a specific method is 
useful, and perhaps even more important is what you're actual goal is.

cheers,
Derick

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Re: [PHP-DEV] First time contributor (DateTime::setDate PR)

[Bilge]

On 02/04/2024 14:14, Derick Rethans wrote:

Hi,

On Sun, 31 Mar 2024, Bilge wrote:


About the PR: I sometimes find it would be useful to only update part of the
date. The PR makes all parameters to DateTime(Immutable)::setDate
  optional in a
backwards-compatible manner such that we can elect to update only the day,
month, year or any combination of the three (thanks, in part, to named
parameters). Without this modification, we must always specify all of the day,
month and year parameters to change the date.

As I mentioned to you in Room 11, I am not in favour of adhoc API
changes to Date/Time classes. It has now been nearly 18 years since they
were originally introduced, and they indeed could do with an overhaul.

I have been colllecting ideas in
https://docs.google.com/document/d/1pxPSRbfATKE4TFWw72K3p7ir-02YQbTf3S3SIxOKWsk/edit#heading=h.2jol7kfhmijb

Having different/better modifiers would also be a good thing to talk
about, albeit perhaps on the four mentioned new classes, instead of
adding them to the already existing DateTime and DateTimeImmutable
classes.

In any case, just allowing setDate to be able to just modify the month
is going to introduce confusion, as this will be counter intuitive:

$dt = new DateTimeImmutable("2024-03-31");
$newDt = $dt->setDate( month: 2 );

It is now representing 2024-03-02.

This might be the right answer, but it might also be that the developer
just cared about the month part (and not the day-of-month), in which
case this is a WTF moment.

Picking mofication APIs is not as trivial as it seems, and I would like
to do it *right*.

Feel free to add comments and wishes to the google doc document. In the
near future, I will be writing up an RFC from this.

cheers,
Derick

Hi Derick,

Thanks for your reply!

Indeed, as per your code snippet, this is a WTF moment I had not 
accounted for and confirm the same result with my patch applied. 
Generally, my expectation here would be the month *must* be set to 2, so 
if the day portion will be invalidated by that change, we should either 
throw an exception or implicitly coerce it into range, i.e. (new 
DateTime("2024-03-31"))->setDate(month: 2); == 2024-02-29. However, I 
suppose this is not the conversation we're having as you do not wish to 
change this API at all, which I respect.


Regarding your brainstorm document, I can't understand much of it in its 
current state, and as I am not a subject matter expert, I think you will 
receive much better feedback from others. In particular, I cannot glean 
which four classes you are referring to in that document. Yet what I do 
find interesting is the notion of adding setters to DateTimeImmutable. 
For my particular use-case—producing a collection of dates incrementing 
by year in a Twig template—a trivial year setter would do just fine, 
with the significant caveat that it must implement fluent interface, 
because I need to call it in an expression context (returning a value), 
not a statement context (executing a void function separately). Not that 
Twig cannot execute statements, but it just becomes more verbose, 
cumbersome and less template-like.


If you were happy for me to add getters and fluent setters for year, I'd 
be happy to work on that PR, but for month we're back to the same 
problem outlined in the opening paragraph (and I suppose the same 
problem occasionally applies to year, if the day happens to be set to 
the leap day). Otherwise, I'll be happy to read over your RFC when it's 
ready.


Kind regards, Bilge

Re: [PHP-DEV] First time contributor (DateTime::setDate PR)

[Derick Rethans]

Hi,

On Sun, 31 Mar 2024, Bilge wrote:

> About the PR: I sometimes find it would be useful to only update part of the
> date. The PR makes all parameters to DateTime(Immutable)::setDate
>  optional in a
> backwards-compatible manner such that we can elect to update only the day,
> month, year or any combination of the three (thanks, in part, to named
> parameters). Without this modification, we must always specify all of the day,
> month and year parameters to change the date.

As I mentioned to you in Room 11, I am not in favour of adhoc API 
changes to Date/Time classes. It has now been nearly 18 years since they 
were originally introduced, and they indeed could do with an overhaul.

I have been colllecting ideas in 
https://docs.google.com/document/d/1pxPSRbfATKE4TFWw72K3p7ir-02YQbTf3S3SIxOKWsk/edit#heading=h.2jol7kfhmijb

Having different/better modifiers would also be a good thing to talk 
about, albeit perhaps on the four mentioned new classes, instead of 
adding them to the already existing DateTime and DateTimeImmutable 
classes.

In any case, just allowing setDate to be able to just modify the month 
is going to introduce confusion, as this will be counter intuitive:

$dt = new DateTimeImmutable("2024-03-31");
$newDt = $dt->setDate( month: 2 );

It is now representing 2024-03-02.

This might be the right answer, but it might also be that the developer 
just cared about the month part (and not the day-of-month), in which 
case this is a WTF moment.

Picking mofication APIs is not as trivial as it seems, and I would like 
to do it *right*.

Feel free to add comments and wishes to the google doc document. In the 
near future, I will be writing up an RFC from this.

cheers,
Derick

-- 
https://derickrethans.nl | https://xdebug.org | https://dram.io

Author of Xdebug. Like it? Consider supporting me: https://xdebug.org/support

mastodon: @derickr@phpc.social @xdebug@phpc.social

[PHP-DEV] First time contributor (DateTime::setDate PR)

[Bilge]

Hi Internals,

I created my first php-src PR 
 yesterday and anticipate I 
may have to write an RFC for it. I created a wiki account under the 
handle, "bilge", and the howto  told me 
to request RFC karma here.


About the PR: I sometimes find it would be useful to only update part of 
the date. The PR makes all parameters to DateTime(Immutable)::setDate 
 optional 
in a backwards-compatible manner such that we can elect to update only 
the day, month, year or any combination of the three (thanks, in part, 
to named parameters). Without this modification, we must always specify 
all of the day, month and year parameters to change the date.


To change just one part of the date, StackOverflow users have found 
various novel 
 
ways 
 
to work around setDate()'s current limitation, which generally involves 
calling format() twice, to isolate the specific date parts that should 
remain constant, and feeding them back into setDate() so they are 
effectively unchanged. All this leads me to wonder why we can't just 
call setDate() with only the parameters we want to change. This is 
particularly useful when generating a collection of dates that only 
differ in one aspect (year, day) and/or when working in a templating 
environment, such as Twig, where doing all the format calls results in 
multiple statements and logic overhead that we should like to avoid in 
templating contexts.


Looking forward to hearing your thoughts.

Cheers,
Bilge