PHP: Cracks in the foundation

http://phpadvent.org/2011/cracks-in-the-foundation-by-gwynne-raskind

by chrismsnz • 15 years ago

134 76 15 years ago

Learning PHP is how I got into web programming, and for that I'll be eternally grateful. Since starting to explore languages like Ruby and Python however, I've been reluctant to use PHP in situations where others are an option, so I'm really glad to hear things are picking up in PHP's development—it can only mean good things for the development community.

MrEnigma2• 15 years ago

This list seems a bit tired.

There are a couple of things in here that are actual issues, but they seem small in scope, and easy to work around.

As for the is_a changes, I think it's probably for the better, as they say, you have to break some eggs to make an omlette. Also, the article first complains about not having Unit Tests to catch this, and then later complains about it being ignored on release. Ultimately unit tests are great for refactoring, but when code is actually being changed, some sort of process needs to be followed for that (dictatorship, consensus building, anarchy?)

I program in PHP, and we don't depend on too many outside libraries. And for cases where we do, we will simply fix these issues.

It used to be that upgrading PHP was much 'easier' to do, meaning you'd just go out and do it, and would hardly breaking anything (at least in my experience). However lately it seems that the risk is higher. However I welcome this, because it means the language is progressing and we're getting a lot of additional things. For all the projects I've worked on, we make sure the code works with that version of PHP. Unit/integration/regression/selenium/using it on development for awhile/whatever are all valid things to do, if you have issues you fix them and move on.

5.3 was great, excited for 5.4 with traits as well. It's a great time to be writing PHP.

MrEnigma2• 15 years ago

The array/sorting things are sometimes just things developers will have to deal with until someone makes new methods and deprecates the old ones.

I used to think that the code base needed to be perfect, no extra cruft, only code that's necessary, switch parameter order just to make things match. However in doing so it adds a tremendous amount of pain and risk. My OCD does't want to handle it, and it's always good to strive to get to that point, but ultimately nothing is perfect, so might as well deal.

zzzeek2• 15 years ago

> PHP, being a language intended for beginners,

I've never heard this before. PHP is certainly very easily picked up by beginners, and in my own opinion makes it easy for said beginners to spend years and years not moving very far beyond beginner-level architectural patterns (just look at the source of Wordpress for an example), but do the creators of PHP really consider it to be "a language for beginners" ?

I have an entirely selfish agenda here. The next time some know-nothing manager promises his client "we have the top programmers with years of experience who will write the highest quality code you can get", then demands that we do everything in PHP because that's all he knows, we can say, "really? You're going to charge the client all that money, then give the client an app written in a "beginner" programming language ?"

mechanical_fish4• 15 years ago

All else being equal (i.e. assuming equal functionality and performance), customers would prefer code that's written in "beginner" programming languages. Customers don't always know many things about code, but every single one of them knows how to count money, and they fantasize about replacing their maintenance staff with a bunch of beginners. Hiring competent beginners is difficult enough.

An important aspect of this problem: Even if the overall system is too complicated for beginners to understand, beginners may be able to usefully tinker with the system if it is built out of parts that they understand. The problem with PHP-based systems is that their most complicated parts may need to be built out of PHP, but the bonus is that all their simple parts are also built out of PHP, and often the bulk of the maintenance boils down to tinkering with the simple parts.

dhx2• 15 years ago

This is very important.

Code that is simple is easy to maintain. This is not to say that simplicity wins over the use of complex design patterns and abstractions in every scenario. It's a trade-off that needs to be considered on a case-by-case basis.

This is especially true in the open source arena where it is critical that new developers can come along and read, understand and improve existing code. Code that is too complex will not be understood and will almost certainly lead to errors.

rajbot• 15 years ago

> do the creators of PHP really consider it to be "a language for beginners" ?

Yes. Andi Gutmans, Zend co-founder and PHP developer says:

“the right way to think about PHP is as Visual Basic for the Web.”

http://www.tbray.org/ongoing/When/200x/2006/10/31/Zend-PHP-C...

tef____2• 15 years ago

A language used by beginners is not the same as one designed for beginners.

I would wager that a language designed for beginners wouldn't have so much inconsistency, nor dump the user in a world of security issues with little or no support (XSS, CSRF, SQL injection).

Other people have worked around these issues, but that demonstrates the lack of support within the language.

jeltz• 15 years ago

Agreed, PHP is not beginner friendly even if it might seem so at first.

The lack of built-in XSS prevention in PHP makes it quite terrible as templating language, especially for beginners who probably have never heard of XSS. The same applies to the simplciity of string interpolation combined with the terrible built-in MySQL driver which makes parametrized queries harder than they should be. All this used to be even more confused by the Magic Quotes in previous versions of PHP.

With so many security traps it is not a language I would recommend for beginners who just want to build something that works.

einhverfr8• 15 years ago

Personally I think there are better languages for beginners than PHP. I think Javascript, Perl, Python, and more are fundamentally better in this regard. There are some fundamental, lexical problems with PHP in this regard. I think by a "language intended for beginners" I think it is meant as "a language intended to allow HTML/SGML authors to cross over into programming."

PHP is in essence a fairly narrow tool, much like a chasing hammer (which really isn't that good for driving nails but is extremely important in some kinds of metal work). It is a preprocessor for SGML files (and this is why all programming logic is typically put in SGML PI tags). I call it a "templating system turned on its head" because whatever you do with PHP, every file is lexically part of the template even those which have no other SGML tags other than the PI tag which is indicating programming logic.

But what this means is it works very well in its own specific domain (namely preprocessing HTML, XML, and other SGML files), but degrades quite a bit as one gets out of this area. This limits code reuse basically to web apps (yes, I know you can write GTK apps in PHP, but really? why on earth would you want to?) and thus locks one into essentially one set of technologies. So there are drawbacks as well as advantages.

blindhippo2• 15 years ago

Totally agree. In addition, PHP is a freely available, incredibly pervasive language that can be installed and run on even the most inexpensive web hosts. There is almost no messy configuration or server setup to be done.

So for a beginner web developer, all they need is a GoDaddy account and a couple tutorial guides.

The sad thing is that many developers stop here. They don't go on to figure out how PHP and Apache work together, how memory gets used and how to manage it effectively. They don't get exposure to proper coding standards (PHP's common standards are horrible IMO). And more often then not, a PHP developer learns how to code in isolation.

Coding should be developed as a mentored skill.

mechanical_fish4• 15 years ago

PHP is indeed a "templating system turned on its head" (according to second-hand reports from a talk by Rasmus Lerdorf, PHP was originally designed as a bare-bones templating system for C programmers, but then more and more stuff migrated into the templating system...). And it is, indeed (or was, anyway) tied strongly to a single domain, and a limited set of architectural patterns.

But every design choice cuts both ways. These features are not merely drawbacks. These are PHP's strengths, the things that make it so delicious for "HTML authors who need to cross over into programming".

You can learn PHP with Google. My understanding is that most people do. [1] Just Google all your problems and up will pop some code that you can mimic. This works because, to first order, all PHP code is solving the same problem in the same way. You will probably not accidentally Google up some PHP-based physics simulation. You will probably not Google up some PHP code used by sysadmins to parse the output of pipes on the command line. You will certainly not Google up any PHP-based graphics algorithms or device drivers or client-side DOM manipulations or Android system functions. No, when you Google "how to do X in PHP" you'll get some code that you can paste into a template with a .php extension and then execute on your cheap shared host. Until fairly recently there wasn't even any danger of encountering object-oriented PHP.

You can argue that programmers trained in this way are useless for anything but cobbling together Web pages, and you're right, but 90% of them don't care. Web pages are a killer app. People build whole businesses out of cheesy web pages.

My suspicion is that many PHP tinkerers don't want more "architectural flexibility"; that translates into "decisions that we have to make but don't know how to make", "knobs that we have to set carefully but which we don't even know how to turn", and "oodles of online documentation for use cases that we don't have, which chaffs up the search results for the use cases that we do have."

The irony, of course, is that PHP's maintainers have been hard at work bolting features from other languages onto PHP, which as a side effect threatens to destroy the narrow domain-specificity that was its most unique feature. [2] Objects, namespaces, closures have all been welded onto the superstructure. One wonders what happens next. Maybe the folks who embrace all these things will drag the entire PHP community closer to Java, Python, Ruby, or some oddball superposition of these things. But I think it more likely that the community will continue to balkanize, with the bulk of users rejecting all these transplants but certain segments embracing one or another of them.

---

[1] I learned PHP via reading and hacking on Drupal modules, which is a much better plan, but also definitely not the beginner-friendly choice. Drupal has a steep learning curve.

[2] Though don't blame the maintainers too much: These features are in fact in demand, from the people who took up PHP without realizing that it was a narrow domain-specific language and pushed it right up to the limits of the available hacks.

tnorthcutt• 15 years ago

...beyond beginner-level architectural patterns (just look at the source of Wordpress for an example)...

Can you expand on this, specifically as it relates to WordPress? I work with WordPress, so I'm curious as to what about it you'd consider beginner-level architectural patterns.

(And FWIW, I'm not trying to start an argument - I'm actually genuinely wanting to learn, thus my question)

zzzeek2• 15 years ago

Not having worked with WP in a couple of years, I actually downloaded the latest wordpress to see what the code looks like these days just to see if it had been improved much (edit: before I posted my original post). For each line of code, you can roll the dice - is this line part of the presentation, is it part of application logic, or is it part of the scaffolding ? It's essentially random on a line by line basis.

Example ? Check out this file:

http://core.svn.wordpress.org/trunk/wp-admin/edit-comments.p...

there, you will see SQL statements, tons of application logic, as well as HTML output rendering. A large amount of the HTML rendering is additionally not templated but rather a long line of imperative string concatenation calls. It's all the worst examples of what PHP has encouraged, all in one file. The enormous quantity of source files present in Wordpress, most of them non-self-explanatory, is a product of this style of design.

paulhauggis3• 15 years ago

PHP has already proven itself time and time again. There are lots of high-traffic websites running PHP successfully. Yes, it's easy to make a simple script and get it running fast, but you can also engineer complex OO applications.

One of the reasons I've stayed away from things like rails is because it puts too many layers on top of things like the database.

I've known a few developers that use Django or Rails and have no idea how things work underneath. This is a disadvantage. Especially if you need to do something like optimize a database query and to do so, you have to actually change the framework that maps SQL to an object.

andrewvc• 15 years ago

I've known a few developers that use Django or Rails and have no idea how things work underneath. This is a disadvantage.

Seriously, that's not even an argument, it's an anecdote of dubious validity.

My personal experience as a rails developer has been that most of the people I've worked with know SQL quite well, and are fully capable of writing straight SQL when required.

Really though, I'm only offering a counter-point. If you truly want to make the case that NOT_YOUR_FRAMEWORK_DEVELOPERS are ignorant, please prove it statistically or find a forum other than hacker news to flame on.

paulhauggis3• 15 years ago

"Seriously, that's not even an argument, it's an anecdote of dubious validity."

I don't have to prove anything. This is why I started it out with "I've know a few developers".

"NOT_YOUR_FRAMEWORK_DEVELOPERS are ignorant, please prove it statistically or find a forum other than hacker news to flame on."

You are one of the problems with hacker news right now. I was merely stating my opinion. Nowhere did I say "all developers". Just because my opinions is different than yours doesn't mean I am trolling or flaming.

Also, when assembly went out of style and c became popular, less and less developers knew how things worked at a lower level. It makes sense that the same thing will happen with frameworks and libraries that are at a higher level.

murz2• 15 years ago

I've never really understood this argument. Yes, it's a disadvantage to "have no idea how things work underneath". But why can't you know how things work underneath and still use the abstraction layer? You can even log the SQL queries it generates, and drop down to custom SQL queries if necessary. If you're paying attention to what's going on "underneath", what is the problem with using abstractions that remove some boilerplate?

paulhauggis3• 15 years ago

"You can even log the SQL queries it generates, and drop down to custom SQL queries if necessary. If you're paying attention to what's going on "underneath", what is the problem with using abstractions that remove some boilerplate?"

In most of the frameworks I've seen, to do so means to hack around the base framework. It's also much faster to just write the correct query in the first place rather than logging every query from the framework and trying to change them for each situation that requires optimization.

flomo4• 15 years ago

The problem with your statement is the equivalent developer is extremely common in the PHP world. There's tons of people who hack on WordPress or Drupal and 'have no idea how things work underneath'. It's probably the majority of people with "PHP" on their resume.

knieveltech2• 15 years ago

I call bullshit on your Drupal FUD. You can't code effectively for Drupal without a robust grasp on basic PHP, SQL and the Drupal suite of hooks. You better have some serious OO chops too or integration with stuff like Views is going to eat your face.

blindhippo2• 15 years ago

As a "Drupal Developer" I can verify this is so true. It makes hiring competent developers in this space nearly impossible. Most of the people that I compete against know how to barely cobble together a couple modules and think that putting some hackey PHP code into a view field (which is stored in a database) is "coding".

Or that coding of any sort is some how not "The Drupal Way". I despise these people.

I would counter, however, that any developer who can accurately explain from start to finish how Drupal handles a request is worth their salt.

rickmb• 15 years ago

And I use PHP in the same way Django and Rails developers do: with frameworks, ORM's and other libraries that do put abstract layers on top of things like the database.

PHP fully supports these use cases and everything in between. The same is true for Python and Ruby, but their web development ecosystem gravitates much more towards single solutions (Django, Rails).

Yes, that means many Django or Rails developers have a hard time developing outside the box of their framework. However, on the PHP end you often see a lack of knowledge of the tools available and a strong tendency towards "not invented here".

It all comes down to making informed choices. The language doesn't make that much of a difference. Every language allows you to optimize db-access to the point of writing raw SQL queries, and no framework can stop you from leveraging the raw power of the language.

damncabbage• 15 years ago

  However, on the PHP end you often see a lack of knowledge 
  of the tools available and a strong tendency towards "not 
  invented here".

You are dead on the mark with this one. I have hopped from place to place, and have needed to explain automated deployment, dependency injection, automated testing, schema management (eg. migrations), VCS branches...

In most cases some of these would be covered by half-baked in-house "solutions", and others wouldn't even be dealt with at all. In other cases the current (knowledgeable) team would still be suffering from the sins made by developers past. I eventually gave up and moved to the Ruby world where most of this stuff is taken for granted.

I don't mind PHP's quirks so much anymore; it's more the ecosystem that comes with it that infuriates me.

necro3• 15 years ago

I was at conference recently talking to a group of "developers" and one finally asked, so what kind of language requirements do you have of the people you hire. I answered that I don't really have any requirements of the specific language. They all looked at each other and nodded, oh, so you must not be too advanced as you are not looking for people with experience in new advanced languages. I was a little surprised because I was thinking the EXACT opposite. I work with _developers_. I don't really give a shit what syntax they prefer of are used to. If you can create your own framework error handling, message queues, custom db libs, etc then that is useful. A real dev can pick up a new language and syntax in a week, so just because you can write hello world in 10 languages or use some rails ORM to output some stuff does not make you a developer.

It's all starting to take me back to my youth watching Robotech and remembering the Zentradi, an advanced race with awesome technology and tools that were developed for them generations ago, but none of the understood how any of it worked or how to fix it, they could only use it. If it broke, they just start over with a new copy instead of debugging it. I hope that the our new generation wont end up like that.

I recently interviewed a recent CS grad that had no idea of the correlation of array of characters and pointers to those characters. You know that it's all just addresses to memory, right?

Anyway, of course there are those who truly dissect and get all the languages and their benefits but are few and between.

Give me a dev that "gets it" in one language any day, instead of someone who thinks remembering the function call or some syntax in 10 languages is of value.

If I hire someone here is how I rank them... 1. 5 years experience in C 2. 5 years experience in PHP 3. 5 years experience in Rails 4. 5 years experience in Rails, Python, erlang, java, php, c, other languages dujour.

Ok, there are people that are just picking up PHP and don't know squat, but at least they know they are beginners and are teachable.

dhx2• 15 years ago

You don't need 5 years of experience in any single language to have a solid understanding of the fundamentals of computing and programming.

I'd rather hire someone that can give you an approximate assembly of a C function (as executed by a CPU), understand how XML documents are stored in memory for efficient querying and parsing, know how to avoid cross-domain browser security problems, have an understanding of multithreading (locks, semaphores, race conditions, etc) and an application of recursion in some other language. I wouldn't care what the knowledge is, as long as it is well rounded and demonstrates that the candidate is capable of pulling apart complex systems to gain a deep understanding in a short period of time. The ability to reason (with passion and authority) about which language or pattern is best suited to a given scenario is also vital.

Time is a terrible measure, partly because it fails to recognise that 5 years of bad/shallow/incorrect experience is worse than 2 weeks of gaining a deep understanding of a new language/pattern.

tef____2• 15 years ago

To echo your sentiment, It's a bit like measuring writers not by the books they have written, but how long they've sat in front of a keyboard.

Anecdotally, Not only is time a a poor measure of ability, those who use it as such demonstrate a lack of accomplishment. Compare those who write "N years of Language X" vs "Wrote A,B,C in Z using ...".

I find "I've used X for N years" to mean "I've done one year of X over and over and over" :-)

necro3• 15 years ago

I think we're getting at the same thing. The time example is used as a comparative generalization that there is a need to focus and understand the fundamentals. The point being that given some period of time, if an average individual chooses to learn 10 languages at once, they probably wont master the fundamentals, compared to mastering those in one language. Of course there is the side case that comparing different languages and their patterns will actually be even more valuable in overall understanding, I would have to side that one first needs a deep enough understanding for that to be an advantage.

nxn2• 15 years ago

> A real dev can pick up a new language and syntax in a week ...

So am I not a real developer because it took me longer than a week to get a hang of Haskell? Hell, it even took me many months before I understood JavaScript well enough to find the right mix of patterns and practices to write solid code in it.

benmathes• 15 years ago

There's a definite difference between "pick up the syntax" of a language that doesn't have (m)any new concepts to wrap your head around versus learning new concepts embedded in a language.

Javascript has closures and functions-as-first-class-objects. Haskell has monads and all that jazz (I haven't used it yet). I'm guessing you didn't take months to learn the syntax of javascript, but to think in javascript.

It's similar to the difference between being functional in a natural language versus being fluent in said language.

flomo4• 15 years ago

"Pick up the syntax in a week" is a huge black flag in my book because it indicates the developer doesn't really understand why his paycheck shows up every 2 weeks. Expertise is learning an environment's vernacular, gotchas, and detailed ins-and-outs of the frameworks/apis. It has nothing to do with passing a Programming Language 101 class.

cmiles742• 15 years ago

It took me months to feel like I wasn't doing something dumb every time I coded in Clojure. There are exceptions to every rule!

dam5s• 15 years ago

Didn't know Rails was a language... interesting. I'll take someone that writes down ruby on their resume over the same rails experience any time!

regularfry2• 15 years ago

By the same token, someone who writes "ruby" with only Rails experience is not off to a good start.

necro3• 15 years ago

That is the scary part isn't it. I'm sure only ruby users exist and that's awesome, but I would wager that most ruby users in the web field are rails users, and many blur where one starts and the other begins.

Peaker• 15 years ago

"A real dev can pick up a new language and syntax in a week,"

This sentiment is true for many languages, as the difference between them is not conceptual, merely syntax and some details.

Learning a programming language that uses different concepts and not just different syntax (e.g: Haskell, Ocaml) will take significantly longer (and IMO will be worth it).

masklinn4• 15 years ago

> This sentiment is true for many languages, as the difference between them is not conceptual, merely syntax and some details.

Even when the core conceptual difference is small and looks like "merely syntax and some details", different languages use different idioms, different standard tools and different methods, usually with reasons (stated or not) behind that. It's the idea behind PJE's (fairly old by now) "Python is not Java": going from Java to Python, the differences look superficial. You declare classes differently, names don't have types and methods are preceded by `def`.

Yet if you just translate your Java code into Python 1:1, you usually end up with an unmaintainable and slow morass, and although the core abstractions are the same Python and Java offer different toolsets to deal with actual problems.

masklinn4• 15 years ago

> A real dev can pick up a new language and syntax in a week

No, that's complete bull. A real dev can pick up syntax in a week (or a day), but integrating concepts and techniques he's never seen so far and building up new instincts which correctly fit the new language, that does not happen in a week unless the guy is in the "genius" category.

What you really have after a week is a guy who writes $previous_language code in a new syntax. In the way "Real Programmers" can write Fortran in any language.

regularfry2• 15 years ago

It does depend which other languages they've previously been exposed to. I'd argue that once you've seen Haskell, common lisp, APL and Forth, there aren't many new concepts that any language is going to throw at you that you can't relate back to something you've seen before. It doesn't take a genius to get that much exposure, just curiosity, patience and time.

philjackson• 15 years ago

I totally agree - there's also the point about a language's eco-system. For example, Perl has CPAN and CPAN brings with it conventions, issues and quirks that take a good few months to (gradually) learn.

cmiles742• 15 years ago

There's definitely some truth to this and I've seen it myself. Nonetheless, there is a point where these languages begin to have more similarities then differences. By the time I felt comfortable with C, Java, PHP and Ruby it only took me a couple of weeks to feel like I had a decent handle on Python.

That said, I'm sure there are a lot of Python specific techniques that still elude me and I continue to read through the source for libraries I'm using.

wwweston3• 15 years ago

It's totally true that it takes time for your idioms to catch up with the capability of the syntax. Maybe the big (and common) mistake the parent is talking about, though, is assuming that because a given programmer knows Blub but doesn't know Blam (generic language with some semantics either not supported, under-supported, or not often used in Blub), they will find the concepts in Blam strange and difficult to adapt to. They may already be familiar with a similar concept or even writing something like Blam-flavored Blub.

I'm a latecomer to the Ruby game, and have done a lot of PHP and JavaScript over the last 10 years (though those are far from the only languages I know and have worked in). It's been funny to see what kind of assumptions that means other devs make about what Ruby concepts are going to be big steps for me. I was told by some people that blocks would be a revelation and that metaclass manipulation would melt my brain. But blocks map pretty directly to the familiar concept of passing around functions, and metaclass hacking onto things present in Perl and JavaScript that I'd sometimes wished I'd had in PHP.

Similarly, Haskell and Erlang -- while significantly different from the languages I've used most of my professional life -- both feel pretty familiar after a long-ago stay in the land of Prolog.

I understand the impulse to assume you know something about a developer from the languages they claim proficiency in -- and the impulse to assume that devs who don't know the languages your revelations have come in haven't had those revelations. Generally, for example, I don't think particularly well of a lot of my fellow PHP devs. But when it comes time to make serious judgments like hiring, rather than asking them which languages they know, I want to look at whether they understand certain semantics at a language-independent level, I want to know what they like about the languages they know, what they'd add to the language if they could, and what they'd take away.

einhverfr8• 15 years ago

It;s funny. I get asked what language requirements people should have about hiring LedgerSMB developers. And I say this:

1) If you can, find someone with good, demonstrable SQL and PL/PGSQL experience.

2) If you can't find that, get someone who is competent in developing on Oracle.

"What?" comes the reply, "Don't they need to know Perl?"

I tell them that the use of Perl we have is getting more minimalistic and simpler, and that we are trying to make it so any competent developer can pick it up quickly.

The same would go if I was writing something similar in PHP. The issue is what sorts of fundamentally different technologies you can address, and the extent to which you feel comfortable working in both declarative, set-oriented worlds and object oriented approaches. The syntax on top of that is really less of an issue.

rhizome2• 15 years ago

Well yeah, if you're moving all of your business logic into the database you're going to want DB-centered people.

EDIT: login -> logic

gbog• 15 years ago

So you are on the side of those relativist who think that all languages are equals or have their own fields of use where they are better than others, and that syntax doesn't matter, that indented or bracketed blocks are just a matter of taste, that cleanliness and homogeneity of syntax and grammar is subjective?

I dare to differ. Hiring a dev for things web, I could ask what language they prefer and why. Someone saying he prefers PHP because it is clean and well organised would get a downvote. If he says it is because it is fast, and that the dirtiness can be avoid by proper training, that would be better. To someone who'd say Ruby, I'd ask what he dislikes about it, or is there any pitfalls. If he knows of no pitfalls, I would have a downvote. Someone saying he don't care at all, would have a double downvote. A good answer would probably be "I'm happy to work with any language but if I have to build something new and can choose the technology I would consider python because I like this tool very much and I'm quite seasoned with it".

Same with code editor: Engineers, developers are using tools and if they have a little bit of a love affair with their job, which is necessary if one want to work hard creating a nice product, they probably have some strong feelings about these tools, which are not all made equal before God.

wwweston3• 15 years ago

I regret I have but one upvote to give to your comment. :)

Instead I'll add this:

"Whenever I interview a candidate I always work in some variation of a very simple question: 'How would you change your favorite programming language to make it better?'

"I don’t really care what the answer is (that is, I don’t mind if we disagree). However, I care very much that people think critically about the tools that they use and love."

http://blog.fogus.me/2011/04/26/my-favorite-interview-questi...

grandinj• 15 years ago

But it can be fixed. Rather than specify a grammer in BISON and generating C code, write your parser as a recursive descent parser. Then add some annotations and auto-generate grammar files from the C code.

This is the same principle as generating document using DOXYGEN, the closer the annotation is to the code, the more chance there is of the annotation being correct.

Also, its something you can incrementally.

seanchambers• 15 years ago

I havent developed in php in years, but here is my tale on it from my current point of view.

Of this whole article the one thing that jumped out at me was "broken and ignored tests". Being an open source developer myself, I greatly value the tests in every open source project. Nevermind the fact that this is PHP which warrants the use of tests even further because of the various points the author makes.

I hope that going forward the maintainers of the PHP core ensure that every bug fix has a passing unit test along with it. That would at least keep the dam holding back the flood intact.

justincormack• 15 years ago

Adding tests for bug fixes doesnt necessarily help when your code is in that state. I think you are better off looking for coverage on tests, and trying to write specs eg formalize the parser as mentioned. Probably a lot of tests now are from previous bugs, but the code has drifted and they have not been maintained.

PHP: Cracks in the foundation

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