5 ms·

Hooray! \o/ I haven't had a use for this yet, but I'm always amazed by how PHP manages to move forward without breaking BC.

AlexMax 12y ago
> I haven't had a use for this yet, but I'm always amazed by how PHP manages to move forward without breaking BC. This. If I were a Python developer (of the language itself), I would be paying very close attention to how PHP has handled deprecation and breaking changes.
- TazeTSchnitzel 12y ago
  There's been an effort with PHP 7 to try and avoid a Python 2/3-style situation. The PHP 5 to 7 jump should be much smaller than from 4 to 5.
  - Danack 12y ago
    >The PHP 5 to 7 jump should be much smaller than from 4 to 5. And also the jump from 5.4+ to 7 is probably smaller than the jump from 5.2 to 5.3. Although I think the PHP project does need to support versions for longer, the adoption rate of 7 is going to be quite rapid due to the low barrier of doing it, and the massive performance and language gains.
- imakesnowflakes 12y ago
  Like this? http://www.reddit.com/r/lolphp/comments/2wse9i/just_ran_into_this_one_php_backward_compatibility/ http://www.reddit.com/r/lolphp/comments/2wse9i/just_ran_into...
- Latty 12y ago
  Really? I see it as the exact opposite. Sure, Python added some pain from 2-3. They did so to fix the main flaws in the language and remove deprecated stuff. The language is now far better and the cost has mostly been paid. The alternative is the PHP approach where everything hangs around for ever, and everyone is using deprecated stuff, everything is named weirdly and lots of extra gunk has to be shoved in to try and make it work in a sane way because "we didn't want to break anything". I understand why some people prefer that, and why it's the way most languages go (Java does the same thing, just with way less movement in general compared to PHP), but it means that the language gets worse over time. Eventually, if you don't do that breaking change, the language will get replaced by something that doesn't need all the cludge.
- ChikkaChiChi 12y ago
  Python 2 -> 3 did not have the luxury that PHP did with 4 -> 5. Python still worked, whereas PHP 4 was running around with its hair on fire screaming for a fire extinguisher that was PHP 5. Bad analogy, but the point is that Python still worked for most people so the upgrade process was slow. I think Go is going to have issues similar to Python when they make the jump to 2.0. The devs are already on record saying that BC will break.
smt88 12y ago
You've had a use for this ever since you started writing code. You just haven't realized it yet.
- arenaninja 12y ago
  Since I can't see the forest from the trees here, care to provide an example or two? I've had cases where I want to only allow certain values (most often int) into certain functions (usually __construct, when looking at a primary key in a database), but in these cases I prefer to cast values. (int)$foo hasn't failed me yet, and I've internalized it as much as I've internalized running application output through htmlentities. I can see this being extremely useful if you plan on using PHP as a general purpose language, but I never have. I'd rather jump to Java/C++/Rust if I had to do numeric calculations (things like images, real time calculations, etc.)
  - smt88 12y ago
    Let's say the constructor you mentioned is for an ORM. Let's also say you're using a database library or PHP extension that you're not 100% familiar with, or maybe it just has a bug in a new version that you just updated to. You pull out a particular row from this library/extension, and it contains an empty string (or even null) as the value for the primary key field. Using typecasting, you'd get a value of 0, which is wrong. It would fail silently, and you'd only discover the error when you realize you're working on a row with no data. You'd even be able to update the row silently, because "UPDATE whatever SET x = y WHERE id = 0" is valid SQL! With primitive type hints, you'd know immediately that you're getting an empty value from your DB, and you could go straight to fixing that instead. In the past, people have had to write a bunch of unit tests to avoid all these issues. With primitive type hints, you could just type the word "int" and be done with it. All that said, I still say all the people that are excited about this are much better off switching to a strictly-typed language, because my example above is just the tip of the iceberg when it comes to juggling types.
    - marrs 12y ago
      I take your point that this is nice syntactic sugar, but I don't like your example. You wouldn't typecast in this situation. You would check the value with is_numeric() or similar.
tveita 12y ago
They're pretty inconsistent about it. They tend to avoid large deliberate breaks, but you still see smaller incompatibilities. Off the top of my head, here's a case where they changed the output of a hash function between 5.3 and 5.4, breaking it for all previous users. https://bugs.php.net/bug.php?id=60221 https://bugs.php.net/bug.php?id=60221
- babuskov 12y ago
  The only consistent thing about PHP is its inconsistency ;) Well, at least you know what you're getting into. It's not like they promise otherwise anywhere.

AlexMax 12y ago

> I haven't had a use for this yet, but I'm always amazed by how PHP manages to move forward without breaking BC. This. If I were a Python developer (of the language itself), I would be paying very close attention to how PHP has handled deprecation and breaking changes.

TazeTSchnitzel 12y ago
There's been an effort with PHP 7 to try and avoid a Python 2/3-style situation. The PHP 5 to 7 jump should be much smaller than from 4 to 5.
- Danack 12y ago
  >The PHP 5 to 7 jump should be much smaller than from 4 to 5. And also the jump from 5.4+ to 7 is probably smaller than the jump from 5.2 to 5.3. Although I think the PHP project does need to support versions for longer, the adoption rate of 7 is going to be quite rapid due to the low barrier of doing it, and the massive performance and language gains.
imakesnowflakes 12y ago
Like this? http://www.reddit.com/r/lolphp/comments/2wse9i/just_ran_into_this_one_php_backward_compatibility/ http://www.reddit.com/r/lolphp/comments/2wse9i/just_ran_into...
Latty 12y ago
Really? I see it as the exact opposite. Sure, Python added some pain from 2-3. They did so to fix the main flaws in the language and remove deprecated stuff. The language is now far better and the cost has mostly been paid. The alternative is the PHP approach where everything hangs around for ever, and everyone is using deprecated stuff, everything is named weirdly and lots of extra gunk has to be shoved in to try and make it work in a sane way because "we didn't want to break anything". I understand why some people prefer that, and why it's the way most languages go (Java does the same thing, just with way less movement in general compared to PHP), but it means that the language gets worse over time. Eventually, if you don't do that breaking change, the language will get replaced by something that doesn't need all the cludge.
ChikkaChiChi 12y ago
Python 2 -> 3 did not have the luxury that PHP did with 4 -> 5. Python still worked, whereas PHP 4 was running around with its hair on fire screaming for a fire extinguisher that was PHP 5. Bad analogy, but the point is that Python still worked for most people so the upgrade process was slow. I think Go is going to have issues similar to Python when they make the jump to 2.0. The devs are already on record saying that BC will break.

smt88 12y ago

You've had a use for this ever since you started writing code. You just haven't realized it yet.

arenaninja 12y ago
Since I can't see the forest from the trees here, care to provide an example or two? I've had cases where I want to only allow certain values (most often int) into certain functions (usually __construct, when looking at a primary key in a database), but in these cases I prefer to cast values. (int)$foo hasn't failed me yet, and I've internalized it as much as I've internalized running application output through htmlentities. I can see this being extremely useful if you plan on using PHP as a general purpose language, but I never have. I'd rather jump to Java/C++/Rust if I had to do numeric calculations (things like images, real time calculations, etc.)
- smt88 12y ago
  Let's say the constructor you mentioned is for an ORM. Let's also say you're using a database library or PHP extension that you're not 100% familiar with, or maybe it just has a bug in a new version that you just updated to. You pull out a particular row from this library/extension, and it contains an empty string (or even null) as the value for the primary key field. Using typecasting, you'd get a value of 0, which is wrong. It would fail silently, and you'd only discover the error when you realize you're working on a row with no data. You'd even be able to update the row silently, because "UPDATE whatever SET x = y WHERE id = 0" is valid SQL! With primitive type hints, you'd know immediately that you're getting an empty value from your DB, and you could go straight to fixing that instead. In the past, people have had to write a bunch of unit tests to avoid all these issues. With primitive type hints, you could just type the word "int" and be done with it. All that said, I still say all the people that are excited about this are much better off switching to a strictly-typed language, because my example above is just the tip of the iceberg when it comes to juggling types.
  - marrs 12y ago
    I take your point that this is nice syntactic sugar, but I don't like your example. You wouldn't typecast in this situation. You would check the value with is_numeric() or similar.

tveita 12y ago

They're pretty inconsistent about it. They tend to avoid large deliberate breaks, but you still see smaller incompatibilities. Off the top of my head, here's a case where they changed the output of a hash function between 5.3 and 5.4, breaking it for all previous users. https://bugs.php.net/bug.php?id=60221 https://bugs.php.net/bug.php?id=60221

babuskov 12y ago
The only consistent thing about PHP is its inconsistency ;) Well, at least you know what you're getting into. It's not like they promise otherwise anywhere.