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Inconsistencies between parameter number and index when reflecting a method/function

php.internals

Ollie Read

2 years ago
Hi All, I've been working on a PR that introduces ReflectionFunctionAbstract::getParameter() and ReflectionFunctionAbstract::hasParameter(), to fall more inline with the other method sets we have, as well as just generally making peoples lives easier. The PR is here: https://github.com/php/php-src/pull/10431 These methods accept an integer to retrieve a parameter by its position, or a string to retrieve by its name. So far, I have built this so that if you required the first parameter, it's parameter 0. I treat it this way because the only other place where we deal with parameter indexes, is ReflectionFunctionAbstract::getParameters() which returns the parameters zero-indexed. The question that is holding this PR back is should these methods be 1 indexed, so that the provided position is consistent with the error messages, or how a person would typically count, or should they be 0 indexed to remain consistent with the existing API. Girgias has asked that I pause the PR until we can have a discussion on this mailing list about how to approach it, so I'm looking for feedback on this. --- Best Regards, *Ollie Read*

Benjamin Eberlei

2 years ago
On Thu, May 2, 2024 at 2:51 PM Ollie Read <php@ollie.codes> wrote:
> Hi All, > > I've been working on a PR that introduces > ReflectionFunctionAbstract::getParameter() and > ReflectionFunctionAbstract::hasParameter(), to fall more inline with the > other method sets we have, as well as just generally making peoples lives > easier. > > The PR is here: https://github.com/php/php-src/pull/10431 > > These methods accept an integer to retrieve a parameter by its position, > or a string to retrieve by its name. So far, I have built this so that if > you required the first parameter, it's parameter 0. I treat it this way > because the only other place where we deal with parameter indexes, is > ReflectionFunctionAbstract::getParameters() which returns the parameters > zero-indexed. > > The question that is holding this PR back is should these methods be 1 > indexed, so that the provided position is consistent with the error > messages, or how a person would typically count, or should they be 0 > indexed to remain consistent with the existing API. >
PHP being a mostly zero indexed language I would say it should be getParamter(0) to get the parameter #1 (referred to as 1 in error messages).

Robert Landers

2 years ago
On Thu, May 2, 2024 at 10:22 PM Benjamin Außenhofer <kontakt@beberlei.de> wrote:
> > > On Thu, May 2, 2024 at 2:51 PM Ollie Read <php@ollie.codes> wrote: > >> Hi All, >> >> I've been working on a PR that introduces >> ReflectionFunctionAbstract::getParameter() and >> ReflectionFunctionAbstract::hasParameter(), to fall more inline with the >> other method sets we have, as well as just generally making peoples lives >> easier. >> >> The PR is here: https://github.com/php/php-src/pull/10431 >> >> These methods accept an integer to retrieve a parameter by its position, >> or a string to retrieve by its name. So far, I have built this so that if >> you required the first parameter, it's parameter 0. I treat it this way >> because the only other place where we deal with parameter indexes, is >> ReflectionFunctionAbstract::getParameters() which returns the parameters >> zero-indexed. >> >> The question that is holding this PR back is should these methods be 1 >> indexed, so that the provided position is consistent with the error >> messages, or how a person would typically count, or should they be 0 >> indexed to remain consistent with the existing API. >> > > PHP being a mostly zero indexed language I would say it should be > getParamter(0) to get the parameter #1 (referred to as 1 in error > messages). > >> >> Girgias has asked that I pause the PR until we can have a discussion on >> this mailing list about how to approach it, so I'm looking for feedback on >> this. >> >> >> --- >> Best Regards, >> *Ollie Read* >> >>
Parameter zero is the first parameter. Both are correct, we access memory from the start (0), but as humans, we count total items. You never say I have zero goats and really mean that you have one goat. However, if you wanted to start at the beginning of a line of goats, you'd start at position zero to get the first goat. Robert Landers Software Engineer Utrecht NL

Lynn

2 years ago
On Thu, May 2, 2024 at 10:21 PM Benjamin Außenhofer <kontakt@beberlei.de> wrote:
> > > On Thu, May 2, 2024 at 2:51 PM Ollie Read <php@ollie.codes> wrote: > >> Hi All, >> >> I've been working on a PR that introduces >> ReflectionFunctionAbstract::getParameter() and >> ReflectionFunctionAbstract::hasParameter(), to fall more inline with the >> other method sets we have, as well as just generally making peoples lives >> easier. >> >> The PR is here: https://github.com/php/php-src/pull/10431 >> >> These methods accept an integer to retrieve a parameter by its position, >> or a string to retrieve by its name. So far, I have built this so that if >> you required the first parameter, it's parameter 0. I treat it this way >> because the only other place where we deal with parameter indexes, is >> ReflectionFunctionAbstract::getParameters() which returns the parameters >> zero-indexed. >> >> The question that is holding this PR back is should these methods be 1 >> indexed, so that the provided position is consistent with the error >> messages, or how a person would typically count, or should they be 0 >> indexed to remain consistent with the existing API. >> > > PHP being a mostly zero indexed language I would say it should be > getParamter(0) to get the parameter #1 (referred to as 1 in error > messages). > >> >> Girgias has asked that I pause the PR until we can have a discussion on >> this mailing list about how to approach it, so I'm looking for feedback on >> this. >> >> >> --- >> Best Regards, >> *Ollie Read* >> >>
The parameter number always confuses me because parameter 4 is actually the 4th, not the 3rd like I'd expect if I look at the indexes when `...$parameters`. Whenever I get an error about parameters I always have to triple check and it costs me extra time to verify the number. I wouldn't mind having this number be consistent with the array indexes instead. I write Lua on a regular basis and everything starts with 1, but it's consistent in the behavior so I never have to think twice.

Lynn

2 years ago
On Fri, May 3, 2024 at 9:28 AM Lynn <kjarli@gmail.com> wrote:
> > The parameter number always confuses me because parameter 4 is actually > the 4th, not the 3rd like I'd expect if I look at the indexes when > `...$parameters`. >
I wish we had a proper system so I could edit my message instead of bothering everyone with an additional reply, I meant to say index 3, not the 3rd parameter.

Derick Rethans

2 years ago
On 2 May 2024 13:48:36 BST, Ollie Read <php@ollie.codes> wrote:
>These methods accept an integer to retrieve a parameter by its position, or a string to retrieve by its name. So far, I have built this so that if you required the first parameter, it's parameter 0. I treat it this way because the only other place where we deal with parameter indexes, is ReflectionFunctionAbstract::getParameters() which returns the parameters zero-indexed. > >The question that is holding this PR back is should these methods be 1 indexed, so that the provided position is consistent with the error messages, or how a person would typically count, or should they be 0 indexed to remain consistent with the existing API.
0-indexed, as that's what PHP does everywhere else. cheers Derick

Gina P. Banyard

2 years ago
On Thursday, 2 May 2024 at 21:33, Derick Rethans <derick@php.net> wrote:
> On 2 May 2024 13:48:36 BST, Ollie Read php@ollie.codes wrote: > > > These methods accept an integer to retrieve a parameter by its position, or a string to retrieve by its name. So far, I have built this so that if you required the first parameter, it's parameter 0. I treat it this way because the only other place where we deal with parameter indexes, is ReflectionFunctionAbstract::getParameters() which returns the parameters zero-indexed. > > > > The question that is holding this PR back is should these methods be 1 indexed, so that the provided position is consistent with the error messages, or how a person would typically count, or should they be 0 indexed to remain consistent with the existing API. > > > 0-indexed, as that's what PHP does everywhere else. > > cheers > Derick
Well not really, if you have an error (TypeError or ValueError) which indicate what parameter is the problem, it will be 1-indexed. Which, for me, makes it more logical to have it 1-indexed. If the ReflectionFunctionAbstract::getParameters() API did not exist, this is what I would have pushed for. Moreover, PHP already has a 1-indexed and 0-indexed discrepancy with the ob_get_level() and ob_get_status() functions. In the end, I don't really care what we choose, but this just needed clarification from internals on how to proceed. Best regards, Gina P. Banyard

Robert Landers

2 years ago
On Fri, May 3, 2024 at 4:01 AM Gina P. Banyard <internals@gpb.moe> wrote:
> > On Thursday, 2 May 2024 at 21:33, Derick Rethans <derick@php.net> wrote: > > > On 2 May 2024 13:48:36 BST, Ollie Read php@ollie.codes wrote: > > > > > These methods accept an integer to retrieve a parameter by its position, or a string to retrieve by its name. So far, I have built this so that if you required the first parameter, it's parameter 0. I treat it this way because the only other place where we deal with parameter indexes, is ReflectionFunctionAbstract::getParameters() which returns the parameters zero-indexed. > > > > > > The question that is holding this PR back is should these methods be 1 indexed, so that the provided position is consistent with the error messages, or how a person would typically count, or should they be 0 indexed to remain consistent with the existing API. > > > > > > 0-indexed, as that's what PHP does everywhere else. > > > > cheers > > Derick > > Well not really, if you have an error (TypeError or ValueError) which indicate what parameter is the problem, it will be 1-indexed. > > Which, for me, makes it more logical to have it 1-indexed. > If the ReflectionFunctionAbstract::getParameters() API did not exist, this is what I would have pushed for. > > Moreover, PHP already has a 1-indexed and 0-indexed discrepancy with the ob_get_level() and ob_get_status() functions. > > In the end, I don't really care what we choose, but this just needed clarification from internals on how to proceed. > > Best regards, > > Gina P. Banyard
There's no discrepancy with ob_get_level and ob_get_status. ob_get_level starts at 0 (no ob) and ob_get_status is count(0) with no_ob. count(ob_get_status(true)) === ob_get_level() Robert Landers Software Engineer Utrecht NL

Ollie Read

2 years ago
On Fri, May 3, 2024, at 1:45 AM, Gina P. Banyard wrote:
> On Thursday, 2 May 2024 at 21:33, Derick Rethans <derick@php.net> wrote: > > > On 2 May 2024 13:48:36 BST, Ollie Read php@ollie.codes wrote: > > > > > These methods accept an integer to retrieve a parameter by its position, or a string to retrieve by its name. So far, I have built this so that if you required the first parameter, it's parameter 0. I treat it this way because the only other place where we deal with parameter indexes, is ReflectionFunctionAbstract::getParameters() which returns the parameters zero-indexed. > > > > > > The question that is holding this PR back is should these methods be 1 indexed, so that the provided position is consistent with the error messages, or how a person would typically count, or should they be 0 indexed to remain consistent with the existing API. > > > > > > 0-indexed, as that's what PHP does everywhere else. > > > > cheers > > Derick > > Well not really, if you have an error (TypeError or ValueError) which indicate what parameter is the problem, it will be 1-indexed. > > Which, for me, makes it more logical to have it 1-indexed. > If the ReflectionFunctionAbstract::getParameters() API did not exist, this is what I would have pushed for. > > Moreover, PHP already has a 1-indexed and 0-indexed discrepancy with the ob_get_level() and ob_get_status() functions. > > In the end, I don't really care what we choose, but this just needed clarification from internals on how to proceed. > > Best regards, > > Gina P. Banyard >
It looks like the consensus seems to be 0-indexed, but I'm happy to allow it a bit more time to get a few more opinions if you'd prefer. I do totally understand what you're saying, though. I think people are typically already capable of differentiation. We know that the first entry in a list array, so entry 1, is index 0. Not to mention the way getPosition() and getParameters() works. --- Best Regards, *Ollie Read*

Derick Rethans

2 years ago
On Fri, 3 May 2024, Gina P. Banyard wrote:
> On Thursday, 2 May 2024 at 21:33, Derick Rethans <derick@php.net> wrote: > > > On 2 May 2024 13:48:36 BST, Ollie Read php@ollie.codes wrote: > > > > > These methods accept an integer to retrieve a parameter by its > > > position, or a string to retrieve by its name. So far, I have > > > built this so that if you required the first parameter, it's > > > parameter 0. I treat it this way because the only other place > > > where we deal with parameter indexes, is > > > ReflectionFunctionAbstract::getParameters() which returns the > > > parameters zero-indexed. > > > > > > The question that is holding this PR back is should these methods > > > be 1 indexed, so that the provided position is consistent with the > > > error messages, or how a person would typically count, or should > > > they be 0 indexed to remain consistent with the existing API. > > > > 0-indexed, as that's what PHP does everywhere else. > > Well not really, if you have an error (TypeError or ValueError) which > indicate what parameter is the problem, it will be 1-indexed.
Which *API* in PHP is 1-indexed? cheers, Derick

Hans Henrik Bergan

2 years ago
On Fri, 3 May 2024 at 17:49, Derick Rethans <derick@php.net> wrote:
> > Which *API* in PHP is 1-indexed? > > cheers, > Derick
Certainly isn't normal but found 1 (and only 1!): $stmt = $pdo->prepare('SELECT name FROM users WHERE id = ?'); $stmt->bindParam(1, $id);

Matteo Beccati

2 years ago
Hi, Il 03/05/2024 17:53, Hans Henrik Bergan ha scritto:
> On Fri, 3 May 2024 at 17:49, Derick Rethans <derick@php.net> wrote: >> >> Which *API* in PHP is 1-indexed? >> >> cheers, >> Derick > > Certainly isn't normal but found 1 (and only 1!): > > $stmt = $pdo->prepare('SELECT name FROM users WHERE id = ?'); > $stmt->bindParam(1, $id);
I suppose numbering is derived from external (database) standards. E.g. Postgres uses $1, $2, etc. as parameter placeholders. Also it is in turn is inconsistent with: $stmt = $pdo->prepare('SELECT name FROM users WHERE id = ?'); $stmt->execute([$id]); That said, 0-indexed for the reflection PR seems the best choice to me too. Cheers
-- Matteo Beccati Development & Consulting - http://www.beccati.com/

Gina P. Banyard

2 years ago
On Friday, 3 May 2024 at 16:47, Derick Rethans <derick@php.net> wrote:
> On Fri, 3 May 2024, Gina P. Banyard wrote: > > > On Thursday, 2 May 2024 at 21:33, Derick Rethans derick@php.net wrote: > > > > > On 2 May 2024 13:48:36 BST, Ollie Read php@ollie.codes wrote: > > > > > > > These methods accept an integer to retrieve a parameter by its > > > > position, or a string to retrieve by its name. So far, I have > > > > built this so that if you required the first parameter, it's > > > > parameter 0. I treat it this way because the only other place > > > > where we deal with parameter indexes, is > > > > ReflectionFunctionAbstract::getParameters() which returns the > > > > parameters zero-indexed. > > > > > > > > The question that is holding this PR back is should these methods > > > > be 1 indexed, so that the provided position is consistent with the > > > > error messages, or how a person would typically count, or should > > > > they be 0 indexed to remain consistent with the existing API. > > > > > > 0-indexed, as that's what PHP does everywhere else. > > > > Well not really, if you have an error (TypeError or ValueError) which > > indicate what parameter is the problem, it will be 1-indexed. > > > Which API in PHP is 1-indexed? > > cheers, > Derick
I have given the 1-index API which is ob_get_level() in my email reply, so I'm confused by the question here. ob_get_level() starts at 1 for the 1st level and increases from there. If the function returns 0 then output buffering is disabled. However, if you retrieve the full statuses of output handlers via ob_get_status() it returns a 0-index array. So to get the correspondence between the output buffer from ob_get_level() and ob_get_status() you need to do +/- 1 with the indexes/levels. I am just pointing out that such a difference in APIs already exists *within* PHP. Like I said earlier, I don't frankly care *what* the consensus is, but considering it was split *within* the reviewers of the PR it needed to be brought to the attention of internals. I find 0-indexing in this case utterly confusing, but that's possibly just me. And if most people are in favour of 0-indexing, then let it be 0-indexing. Best regards, Gina P. Banyard

Claude Pache

2 years ago
> Le 2 mai 2024 à 14:48, Ollie Read <php@ollie.codes> a écrit : > > The question that is holding this PR back is should these methods be 1 indexed, so that the provided position is consistent with the error messages, or how a person would typically count, or should they be 0 indexed to remain consistent with the existing API. >
It ought to be consistent with the existing reciprocal method `ReflectionParameter::getPosition()`, which returns `0` for parameter #1. —Claude

Gina P. Banyard

2 years ago
On Thursday, 2 May 2024 at 13:48, Ollie Read <php@ollie.codes> wrote: > Hi All, > > I've been working on a PR that introduces ReflectionFunctionAbstract::getParameter() and ReflectionFunctionAbstract::hasParameter(), to fall more inline with the other method sets we have, as well as just generally making peoples lives easier. > > The PR is here: https://github.com/php/php-src/pull/10431 > > These methods accept an integer to retrieve a parameter by its position, or a string to retrieve by its name. So far, I have built this so that if you required the first parameter, it's parameter 0. I treat it this way because the only other place where we deal with parameter indexes, is ReflectionFunctionAbstract::getParameters() which returns the parameters zero-indexed. > > The question that is holding this PR back is should these methods be 1 indexed, so that the provided position is consistent with the error messages, or how a person would typically count, or should they be 0 indexed to remain consistent with the existing API. > > Girgias has asked that I pause the PR until we can have a discussion on this mailing list about how to approach it, so I'm looking for feedback on this I am not sure why I had not thought about checking this earlier, but ReflectionParameter has a getPosition method [1], where the first parameter of a function/method is 0. So the _best_ argument for having it 0 indexed based is to be consistent with the existing semantics. So I am fine with having it 0 indexed. Best regards, Gina P. Banyard [1] https://www.php.net/manual/en/reflectionparameter.getposition.php >