Proposed RFC

Hi all,

First off, this is my first time e-mailing internals or even thinking about submitting RFC. Please forgive me if I fail to follow some kind of convention.

In PHP 7.0, we were given the Null Coalesce operator. For example:

   echo $array['key']??"key is not set"

would be the same as:

  echo (isset($array['key'])?$array['key']:"key is not set"

This is a great feature, that makes code much cleaner.

This works on the principle that "$array['key']" is "NULL".

I would like to propose a new feature that is as clean as this but is a slightly different use case. This would require a new operator (up for discussion, but an early idea is "?!") For example:

echo (!is_infinite($n1/$n2)?!0);

Would output ($n1/$n2) if it is "true" and 0 if false.

Right now, the closest we have to this is ?: operator. The problem with this is that it could get very messy as you still have to do:

echo (!is_infinite($n1/$n2)?$n1/$n2:0);

I have obviously over simplified the example. You wouldn't have a big problem in this case, but if the subject of the function is much longer, it can become complicated very quickly.

Alternatively, a perhaps more general feature would be to just have the same functionality as the Null Coalesce, but with true/false rather than Null/Not Null.

Please let me know if there is something in these ideas or anyway to improve them. I should also note that I would need a volunteer to implement this as my "C" skills are non-existent and I wouldn't have the confidence to delve into the the PHP source.

Thanks for your time.

Best,

Antony D'Andrea

Yes I have but I would like it to return ($n1/$n2) or whatever this input is, without repeating it again.

But it should do exactly that, except for a falsy return (eg. zero,
empty, null, false) - note INFINITY is a truth value, so 10/0, for
instance, will return INF instead of "else value".
For instance:

$n1 = 10;
$n2 = 5;

echo ( $n1 / $n2 ) ?: 'ELSE VALUE'; // Will returns 2

$n1 = 0;
$n2 = 5;

echo "\n";
echo ( $n1 / $n2 ) ?: 'ELSE VALUE'; // Will returns ELSE VALUE

2016-11-03 13:56 GMT-02:00 Antony D'Andrea contactme@antonydandrea.com:

Hi,

Yes I have but I would like it to return ($n1/$n2) or whatever this input is, without repeating it again.

---

From: David Rodrigues [david.proweb@gmail.com]
Sent: 03 November 2016 15:48
To: Antony D'Andrea
Cc: internals@lists.php.net
Subject: Re: [PHP-DEV] Proposed RFC

You have tried the ?: operator?

echo !is_infinite($n1/$n2) ?: 0;

It should returns true or 0, for this case.

2016-11-03 13:02 GMT-02:00 Antony D'Andrea contactme@antonydandrea.com:

Hi all,

First off, this is my first time e-mailing internals or even thinking about submitting RFC. Please forgive me if I fail to follow some kind of convention.

In PHP 7.0, we were given the Null Coalesce operator. For example:

   echo $array['key']??"key is not set"

would be the same as:

  echo (isset($array['key'])?$array['key']:"key is not set"

This is a great feature, that makes code much cleaner.

This works on the principle that "$array['key']" is "NULL".

I would like to propose a new feature that is as clean as this but is a slightly different use case. This would require a new operator (up for discussion, but an early idea is "?!") For example:

echo (!is_infinite($n1/$n2)?!0);

Would output ($n1/$n2) if it is "true" and 0 if false.

Right now, the closest we have to this is ?: operator. The problem with this is that it could get very messy as you still have to do:

echo (!is_infinite($n1/$n2)?$n1/$n2:0);

I have obviously over simplified the example. You wouldn't have a big problem in this case, but if the subject of the function is much longer, it can become complicated very quickly.

Alternatively, a perhaps more general feature would be to just have the same functionality as the Null Coalesce, but with true/false rather than Null/Not Null.

Please let me know if there is something in these ideas or anyway to improve them. I should also note that I would need a volunteer to implement this as my "C" skills are non-existent and I wouldn't have the confidence to delve into the the PHP source.

Thanks for your time.

Best,

Antony D'Andrea

--
David Rodrigues

--
David Rodrigues

Thanks everyone for your responses.

It has not taken long to find situations where this idea starts to fall apart. For example, in the case of strpos, I would hope for the return value, but in other cases I would want the the original input if the output is not false.

That makes this feature pretty unfeasible I think!