PHP introduces "goto"(php.net)
php.net
PHP introduces "goto"
http://www.php.net/manual/en/control-structures.goto.php
94 comments
Why is everyone jumping on this as a negative? Goto isn't inherently evil. Of course in most cases there is a construct that would be a better fit than goto, but it does have its uses. As far as readability goes, odds are a programmer isn't going to be jumping to a label 300 lines up, its used mostly to break out of nested loops and to simulate stuff like state machines. Check out http://david.tribble.com/text/goto.html
They already have a break statement to get out of loops of arbitrary depth. http://www.php.net/manual/en/control-structures.break.php
And why, except perhaps for the hack value, would you simulate a state machine in PHP?
GOTOs are good when used wisely in certain contexts. I don't see where they could be of any use in the PHP niche (but I'd be glad to hear about such examples). Seasoned PHP coders don't need it.
Besides, PHP is mostly a beginner's programming language, who learn by example using code found online. They will be exposed to even worse practices from day one.
And why, except perhaps for the hack value, would you simulate a state machine in PHP?
GOTOs are good when used wisely in certain contexts. I don't see where they could be of any use in the PHP niche (but I'd be glad to hear about such examples). Seasoned PHP coders don't need it.
Besides, PHP is mostly a beginner's programming language, who learn by example using code found online. They will be exposed to even worse practices from day one.
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It takes a great deal of discipline to not use goto for quick fixes when you feel lazy. Unfortunately, many PHP programmers simply don't have the experience to properly structure code, since PHP is their first actual experience with programming. While major projects like frameworks and well-established CMS's will likely do fine, smaller-scale projects and codebases will suffer.
It's not negative in that, people can program using whatever language they want using whatever language constructs they want.
But for PHP, which is mostly for web development, I would think using exceptions is a much peer-friendlier way of handling what you'd probably be using goto for in a web app.
If you're writing state machines or parsers, PHP probably isn't the way to go anyway. But hey - whatever floats your boat.
But for PHP, which is mostly for web development, I would think using exceptions is a much peer-friendlier way of handling what you'd probably be using goto for in a web app.
If you're writing state machines or parsers, PHP probably isn't the way to go anyway. But hey - whatever floats your boat.
ugh. they caved. too bad. this kind of hurts their movement towards OO. now we'll probably see see tons of people using goto as bandaid measures instead of learning better techniques to solve their problems. look out for raptors.
It's PHP, it's already a band aid measure.
Adding goto just incremented the keyword count, nothing more. Bad coders will still keep on writing bad code, with or without the help of goto.
Adding goto just incremented the keyword count, nothing more. Bad coders will still keep on writing bad code, with or without the help of goto.
I wish I had more points to give this comment
Why? PHP is not any worse or better than any other language.
You can have bad programmers in any language - PHP just has lots of them because it's a popular language, but there is nothing wrong with the language itself.
You can have bad programmers in any language - PHP just has lots of them because it's a popular language, but there is nothing wrong with the language itself.
I would argue that effectively having roughly 3,000 keywords is a problem of the language itself.
And, saying, "PHP is not any worse or better than any other language" is saying that all languages are equal. Which, having worked in a number of languages over the years, including PHP, I know to be false. PHP is worse than many languages, and better than many for some classes of problem. It's just silly to say that all languages are equal.
And, saying, "PHP is not any worse or better than any other language" is saying that all languages are equal. Which, having worked in a number of languages over the years, including PHP, I know to be false. PHP is worse than many languages, and better than many for some classes of problem. It's just silly to say that all languages are equal.
PHP does not have 3000 keywords. It has an ordinary number, and the rest are functions - basically the standard library.
You are confusing the language and the library. And for that matter the library is not bad either, it does however have a few poorly named legacy functions.
> It's just silly to say that all languages are equal.
Sorry, I wasn't really trying to say that. I meant "loosely typed procedural languages" not "any other language".
You pick the language the matches what you are doing, there is nothing inherent about PHP that makes it bad.
You are confusing the language and the library. And for that matter the library is not bad either, it does however have a few poorly named legacy functions.
> It's just silly to say that all languages are equal.
Sorry, I wasn't really trying to say that. I meant "loosely typed procedural languages" not "any other language".
You pick the language the matches what you are doing, there is nothing inherent about PHP that makes it bad.
PHP does not have 3000 keywords. It has an ordinary number, and the rest are functions - basically the standard library.
A library function that is not optional is effectively a keyword. The PHP standard library (all ~3000 functions) is not optional, as far as I know.
A library function that is not optional is effectively a keyword. The PHP standard library (all ~3000 functions) is not optional, as far as I know.
Many (most?) of them are optional, you can compile PHP with/without certain extensions. Design wise, it seems insane - kind of like the iPhone's non-removable battery. Turns out it doesn't hurt either one's popularity though...
OK, so I really didn't think I needed to specify "at run-time" with regard to the meaning of "optional".
They can be done at runtime, you can dl() whatever modules you want.
However no one bothers. Why? Because while having lots of keywords is a problem in theory, in the real world it doesn't matter at all.
However no one bothers. Why? Because while having lots of keywords is a problem in theory, in the real world it doesn't matter at all.
i think the point that was trying to be made is that PHP has its uses. use it where it best fits to solve the problem. just like any other language.
> PHP is not any worse or better than any other language.
I disagree. Consider the following PHP:
I disagree. Consider the following PHP:
function inc_all($i, $xs) {
array_map($xs, function($x) use ($i) { return $x + $i; });
}
inc_all i = map (+ i)
Haskell is a functional language, PHP is not. So it's not a valid comparison.
Every time I ask people what's wrong with PHP they give me answers from functional languages. I've yet to see anyone give me an example from a procedural language.
Every time I ask people what's wrong with PHP they give me answers from functional languages. I've yet to see anyone give me an example from a procedural language.
"PHP is not any worse or better than any other language."
Haskell fits as "any other".
"Haskell is a functional language, PHP is not. So it's not a valid comparison."
So, PHP is not any worse or better than any other language that's just like PHP?
Haskell fits as "any other".
"Haskell is a functional language, PHP is not. So it's not a valid comparison."
So, PHP is not any worse or better than any other language that's just like PHP?
You're right. Let's compare to a more adequate language. Like Ruby.
def inc_all(i, xs)
xs.map { |x| x + i }
end> PHP is not any worse or better than any other language.
I also disagree, but in the sense that PHP is both better and worse than other languages, depending on your metrics. I feel that talking about code terseness is weird if it takes more effort to actually complete whatever project you're working on (due to lack of libraries, less active community, what have you).
I also disagree, but in the sense that PHP is both better and worse than other languages, depending on your metrics. I feel that talking about code terseness is weird if it takes more effort to actually complete whatever project you're working on (due to lack of libraries, less active community, what have you).
"Why? PHP is not any worse or better than any other language."
False. Not all languages are created equal, and PHP is on the shittier end of the spectrum.
False. Not all languages are created equal, and PHP is on the shittier end of the spectrum.
Really? So back up the statement - tell me exactly what's bad about PHP.
And as I said before, it's a loosely typed procedural language, so don't try to compare it to a functional one. Within that type of language, what's bad about PHP?
And as I said before, it's a loosely typed procedural language, so don't try to compare it to a functional one. Within that type of language, what's bad about PHP?
I like PHP just fine and use it often. But if you really want an answer to that question, I'll give you one: inconsistency. Not saying I don't understand it, and I'm not saying I blame the way PHP has evolved. But it does have a lot of inconsistency.
Are you aware that your challenge is rapidly approaching "without reference to anything better, tell me about PHP's failings"?
The usual technique for evaluating something is to compare it to its competitors, and some of those are functional!
One of the bad things about PHP is that it lacks the higher-order capabilities of most functional languages. It's also inconsistent, easy to write slow code in, makes it easy to introduce massive vulnerabilities, and ugly.
It's 2009. Nobody should be using PHP any more.
The usual technique for evaluating something is to compare it to its competitors, and some of those are functional!
One of the bad things about PHP is that it lacks the higher-order capabilities of most functional languages. It's also inconsistent, easy to write slow code in, makes it easy to introduce massive vulnerabilities, and ugly.
It's 2009. Nobody should be using PHP any more.
PHP is not a functional language. People like functional languages in theory, for the style. But not so much when it comes to actually using them.
And what's ugly about PHP? It looks almost exactly like C.
It is inconsistent (sometimes), but it's not "easy to write slow code in", there is nothing in PHP that makes slow code more or less likely.
It's 2009. Everyone IS using PHP, and almost no one uses functional languages. Oh they get a lot of press, but few deployments.
I'm really tired of these illogical attacks on PHP. No one has ever told me a problem in PHP compared to other procedural languages except that 0 == "" is confusing.
It's always "but everyone knows it's bad". Sure go along with peer pressure if you like, but I prefer to look at reality.
And what's ugly about PHP? It looks almost exactly like C.
It is inconsistent (sometimes), but it's not "easy to write slow code in", there is nothing in PHP that makes slow code more or less likely.
It's 2009. Everyone IS using PHP, and almost no one uses functional languages. Oh they get a lot of press, but few deployments.
I'm really tired of these illogical attacks on PHP. No one has ever told me a problem in PHP compared to other procedural languages except that 0 == "" is confusing.
It's always "but everyone knows it's bad". Sure go along with peer pressure if you like, but I prefer to look at reality.
PHP has to look up variables by name at runtime, because it doesn't know which ones will really exist, much less their types. It doesn't know whether any array will be used as an ordered list or a lookup table, so it has to maintain a complex data structure for both. It has to allow any value to actually be a reference which shares state with any other value. These are very expensive features which preclude a lot of optimizations, yet they're rarely used because they're more often surprising than helpful. We ported an app server from PHP to Java and picked up a 6x speed improvement with hardly any tuning.
And 0 == "" isn't really confusing. You want confusing?
And 0 == "" isn't really confusing. You want confusing?
array(0 => false, 1 => true) == array(false => "0", 1.9 => " 0")
People like functional languages in theory, for the style. But not so much when it comes to actually using them.
Really? I use the functional capabilities of Python and JavaScript all the time when I use those languages.
Really? I use the functional capabilities of Python and JavaScript all the time when I use those languages.
What's bad about PHP is choice.
There are so many languages that use a more elegant syntax, reducing the time (and pain) it takes to prevent and find errors, and add functionality.
Given that there can be both well and badly written PHP, other good language choices in general have a consistent and/or clear choice as it comes to syntax (and less keywords to memorize).
Some choices of dynamic, loosely typed languages are:
Ruby, while perl-inspired provides some very pleasant syntax.
While Python is less pretty, there is generally one good way of doing things. Python code is also often consistent across developers, even if its at a mostly superficial level.
PHP is probably more pleasant to work with than ASP/VBScript, but in 2009, with other choices, if you don't have to use PHP and don't mind trying something new, why don't you?
There are so many languages that use a more elegant syntax, reducing the time (and pain) it takes to prevent and find errors, and add functionality.
Given that there can be both well and badly written PHP, other good language choices in general have a consistent and/or clear choice as it comes to syntax (and less keywords to memorize).
Some choices of dynamic, loosely typed languages are:
Ruby, while perl-inspired provides some very pleasant syntax.
While Python is less pretty, there is generally one good way of doing things. Python code is also often consistent across developers, even if its at a mostly superficial level.
PHP is probably more pleasant to work with than ASP/VBScript, but in 2009, with other choices, if you don't have to use PHP and don't mind trying something new, why don't you?
I agree, but for the record syntax choice is pretty arbitrary; I find Python quite nice to look at, while Ruby looks like a kludge.
PHP is missing many features that good programmers need to write good code. Anonymous functions, lexical environments, the list goes on.
You can write OK code with PHP, but you can't write excellent code.
(And no, I am not implying that code is bad unless you use a lot of anonymous functions. I am just saying that it's an essential tool that you really need when certain situations arise. In PHP, those situations will have to involve hacks.)
You can write OK code with PHP, but you can't write excellent code.
(And no, I am not implying that code is bad unless you use a lot of anonymous functions. I am just saying that it's an essential tool that you really need when certain situations arise. In PHP, those situations will have to involve hacks.)
PHP has anonymous functions, so I guess now you love PHP.
You say the "list goes on" - so I googled for a list http://www.tnx.nl/php.html. And half the things on the list aren't even true! And the rest are style choices (more functions with less parameters, or fewer functions with more parameters).
You say the "list goes on" - so I googled for a list http://www.tnx.nl/php.html. And half the things on the list aren't even true! And the rest are style choices (more functions with less parameters, or fewer functions with more parameters).
Here is a list: continuations, closures (which is what I really meant by anonymous functions and lexical environments, but I guess the term "environment" is not familiar to people that don't program CL), macros, real OO (classes/traits, first-class attributes, a metaobject protocol, etc), a sane type (constraint) system, and so on. Nobody cares about the order of arguments to a function in the standard library, that's trivial to ignore and fix. What PHP is missing is a way to extend the language, which means you are stuck with whatever the designers give you (which sucks hard).
Anyway, if you haven't used these features before, you might not see the need; see the "Blub" essay for details on that.
Anyway, if you haven't used these features before, you might not see the need; see the "Blub" essay for details on that.
I'm pretty sure it's actually worse.
FWIW, Perl has had goto forever, and I have never encountered it in real code. It just isn't necessary.
So I doubt this will make PHP any worse than it already is. They should really consider adding some useful features, though.
So I doubt this will make PHP any worse than it already is. They should really consider adding some useful features, though.
And even if it's seen in Perl land, in most cases it is called with a code reference as argument, not a label, which simply replaces the current item on the calling stack with the code reference. This allows for manual tail-call-optimisation which is quite nice sometimes.
Oh, common. Are we talking about the language that allows run-time renaming of the variables ? I mean if you have that then adding a goto hardly qualifies as "too bad".
How exactly do you rename a variable?
I suppose he means something like:
$foo = 42;
$bar = 69;
$which_one = 'foo';
print eval "\$$which_one";Actually, you don't need the eval in there. print $$which_one will do just fine
Actually, no. That's not it. This is an equivalent of a pointer to a variable in C.
What I was referring to is the actual renaming the variables in run-time, i.e. change variables' key in the table of variables. So the code like this:
What I was referring to is the actual renaming the variables in run-time, i.e. change variables' key in the table of variables. So the code like this:
for ($i = 0; $i < 8; $i++)
{
..
<rename i to j>
..
}
I don't know how you'd do that in PHP, but I'm pretty sure that you can do it fairly easily in Python and Lua, and I've never heard anyone claim that (more or less) first class environments are a feature of bad languages.
You are missing the point. PHP is a very odd and subjectively inconsistent mixture of language features, so adding a goto support is hardly a bad design decision.
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I think we aren't. I have no idea what language you're thinking of.
Sweet! Hope they implement COMEFROM next.
http://en.wikipedia.org/wiki/COMEFROM
http://en.wikipedia.org/wiki/COMEFROM
Most langauges have that. It's called "catch".
It's a bit late for that.
http://cadie.googlecode.com/svn/trunk/
I feel like I've been trolled by the PHP haters again.
All of this language-ism is killing my chi.
All of this language-ism is killing my chi.
I feel this is a relevant cross post, at least for my own amusement:
http://news.ycombinator.com/item?id=650328
http://news.ycombinator.com/item?id=650328
I agree wholeheartedly. C++ has goto, and although it's clear C++ can't learn from the past, at least programmers for PHP can be warned to use goto conservatively.
Error handling and portability of code from other languages will make PHP more widely used. That is the goal of the founders/contributors: make PHP used as widely as possible on it's features alone.
Error handling and portability of code from other languages will make PHP more widely used. That is the goal of the founders/contributors: make PHP used as widely as possible on it's features alone.
So what? If you think goto is harmful, don't use it. If you think PHP in general is harmful, don't use that either. Maybe help build something comparable to Wordpress or Drupal in your favorite language so other people can use it instead of PHP. If all you have to offer is empty sarcasm, goto Reddit.
And then you have to maintain spaghetti code in PHP with gotos.
I've thought of adding goto to Sleep. Have you ever looked at the code in the Linux kernel? It's full of gotos. They use goto's to make sure functions have one exit point and to cleanly deal with errors in one spot.
Kernel hackers know presumably what they're doing and use goto only when they have a good reason. Can the same be said of PHP programmers?
I'm all for the "don't protect programmers from themselves" philosophy, until I'm the guy who has to use or maintain the code.
I'm all for the "don't protect programmers from themselves" philosophy, until I'm the guy who has to use or maintain the code.
Yay! Finally I've been waiting for this for a long time.
I can finally get rid of some spaghetti code: goto emulation via while loops.
Yes, it's not often you need goto, but sometimes you do.
I can finally get rid of some spaghetti code: goto emulation via while loops.
Yes, it's not often you need goto, but sometimes you do.
No way! I do exactly this. Switch statement, while loop, and lots of continue statements.
Its a lowering of basic blocks that I want to print out to test.
What's yours?
Its a lowering of basic blocks that I want to print out to test.
What's yours?
Finally! Now PHP really is the web's assembly language.
So....all the progress PHP has made in recent years has not been undone.....but has been rendered irrelevant. Never again will anyone be taken seriously while using PHP. It will once again be purely the domain of amateurs and script kiddies.
This is being said as someone who has created marvelous applications in PHP and has dealt with all the PHP language shortcomings up to this point. Makes me truly, truly sad.
This is being said as someone who has created marvelous applications in PHP and has dealt with all the PHP language shortcomings up to this point. Makes me truly, truly sad.
This isn't some kind of surprise. It has been discussed for some time now.
There is also no reason for a developer to use it if it's not wanted.
There is also no reason for a developer to use it if it's not wanted.
I understand why C and C++ have goto statements (as well as other older languages). But to actually "introduce" goto's in a language that didn't have it or need it, making it even possible to write such horrible code is, in my opinion, pointless and worthless. It promotes illegible and bad code in general.
Goto is a good idea in C, not only for the obvious low-levelness reasons, but also because if you can write C you are almost certainly a bit wiser than the average PHP programmer that may use goto for things I prefer don't think about before to go to sleep :)
"If you want to go somewhere, goto is the best way to get there"
-- Ken Thompson
I was working for a company doing mostly COBOL programming about a year ago, and I can honestly say that GOTO can be used neatly and effectively, but it can also turn code into a horrible mess. For COBOL, it's an absolute must. There are no while or for loops in COBOL (at least not in the version we were using), so you had to replicate that with GOTO's and paragraphs. For PHP, I really don't see this as necessary.
So long as it's not widely publicized in tutorials and the like, I don't really see a whole lot of novice coders getting their hands on this. I'm not particularly concerned about experienced programmers using GOTO in PHP, especially if they've used in another language where it is more necessary.
So long as it's not widely publicized in tutorials and the like, I don't really see a whole lot of novice coders getting their hands on this. I'm not particularly concerned about experienced programmers using GOTO in PHP, especially if they've used in another language where it is more necessary.
Anyone knows where's the PHP core team blog/site (if there's such team)?
Someone pointed out the minutes-of-meeting http://www.php.net/~derick/meeting-notes.html#adding-goto
This helps quite a bit... It helps people move on from PHP because it is the 'language that later added goto'. A sad day for programmers in PHP.
gotos are a bad programmer's recursive method. Even people that use while loops like pepper scare me a bit. I have seen many'a'app get stuck in memory draining death loops with goto and even while(). Flags are dead, long live events and messages.
gotos are a bad programmer's recursive method. Even people that use while loops like pepper scare me a bit. I have seen many'a'app get stuck in memory draining death loops with goto and even while(). Flags are dead, long live events and messages.
I once used that a lot on my C64. Made sense back in 1982 and in limited cases, makes sense today.
From the page:
"It is not allowed to jump into a loop or switch statement. A fatal error is issued in such cases."
At least that isn't possible. What a mess it would be if this wasn't the case.
"It is not allowed to jump into a loop or switch statement. A fatal error is issued in such cases."
At least that isn't possible. What a mess it would be if this wasn't the case.
Haha, wow how sad. The kind of sadness created when realizing how disgustingly pathetic our evolution can often be.
I can't wait to spend minutes of my life when I have to go through another programmer's PHP code who uses gotos.
I can't wait to spend minutes of my life when I have to go through another programmer's PHP code who uses gotos.
I think you left out your goto CalmDownFirst line in your DramaQueenPreventor class.
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This feels like a giant step towards the past.
Using PHP is a giant step towards the past.
PHP will never fully be utilized as an OO language by the vast majority of its user base due to its syntactically terrible standard library and history as a functional language.
As such, this addition makes plenty of sense.
PHP will never fully be utilized as an OO language by the vast majority of its user base due to its syntactically terrible standard library and history as a functional language.
As such, this addition makes plenty of sense.
Functional language? Did you mean to say procedural language?
I can assure you that PHP is not a functional language (despite all my efforts to make it one).
I can assure you that PHP is not a functional language (despite all my efforts to make it one).
1) its only a step backwards if you're currently using a better language. its a step forward for other people who are way behind, or for people who have no web development experience and want to get started. it a decent and very popular learning language. if someone starts writing about goto in their php tutorials for beginners, we'll have a problem.
2) php is procedural, not functional. (edit: whoops, beaten to this punch)
2) php is procedural, not functional. (edit: whoops, beaten to this punch)
PHP will never fully be utilized as an OO language because it's a stupid idea to write web pages with an OO language.
Web pages are just not suited to OO. Encapsulation can be done via functions - adding OO to it gets you nothing except longer code.
Making things more complicated does not make them better.
Web pages are just not suited to OO. Encapsulation can be done via functions - adding OO to it gets you nothing except longer code.
Making things more complicated does not make them better.
I almost agree with this. I'm experimenting with Kohana for my latest code, and even though this is supposed to be the lean, fast OO framework, there's a LOT of boilerplate associated. Less than a third of my code is actually get-things-done code, as opposed to more than two thirds last time I was using a home-grown, not-especially-OO framework.
Maybe some other framework does this better, though.
Maybe some other framework does this better, though.
This is a giant step towards the past.
Welcome to 1980.
Welcome to 1980.
while() loops are just goto's with some syntactic sugar..
While loops are restricted gotos with syntactic sugar.
Now that I come to think of it, it actually doesn't matter for PHP.
While loops limit the scope of variables inside the loop. For C++, that means a variable declared inside cannot be used outside - logical, and OOP.
But PHP has no concept of privacy or scope, even its "rules" may be broken (though not guaranteed to always work) and come out with the right results. Anything will compile, and usually the results are as expected.
So if you have a while loop with no concept of scope or local variables, I guess the restrictions are gone. A number of nested loops with breaks; and continues; all over end so long as the concept of limited data scope/access is not present as in PHP are exactly equivalent to goto as it is.
I guess a language as, shall we say, 'relaxed' as PHP is well-matched with relaxed keywords like goto.
While loops limit the scope of variables inside the loop. For C++, that means a variable declared inside cannot be used outside - logical, and OOP.
But PHP has no concept of privacy or scope, even its "rules" may be broken (though not guaranteed to always work) and come out with the right results. Anything will compile, and usually the results are as expected.
So if you have a while loop with no concept of scope or local variables, I guess the restrictions are gone. A number of nested loops with breaks; and continues; all over end so long as the concept of limited data scope/access is not present as in PHP are exactly equivalent to goto as it is.
I guess a language as, shall we say, 'relaxed' as PHP is well-matched with relaxed keywords like goto.
No, thats not what he means. He means that gotos are unstructured, and you can do anything with them, like jumping into a loop.
Although, PHP's gotos don't allow they, and PHP still only admits structured control flow.
Although, PHP's gotos don't allow they, and PHP still only admits structured control flow.
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Heh.