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Developer Argues For 'Forgotten Code Constructs' Like GOTO and Eval (techbeacon.com)
mikeatTB quotes TechBeacon:
Some things in the programming world are so easy to misuse that most people prefer to never use them at all. These are the programming equivalent of a flamethrower... [But] creative use of features such as goto, multiple inheritance, eval, and recursion may be just the right solution for experienced developers when used in the right situation. Is it time to resurrect these four forgotten code constructs?
The article notes that the Linux kernel uses goto statements, and links to Linus Torvalds' defense of them. ("Any if-statement is a goto. As are all structured loops...") And it points out that eval statements are supported by JavaScript, Python, PHP, and Ruby. But when the article describes recursion as "more forgotten than forbidden," it begs the inevitable question. Are you using these "forgotten code constructs" -- and should you be?
The article notes that the Linux kernel uses goto statements, and links to Linus Torvalds' defense of them. ("Any if-statement is a goto. As are all structured loops...") And it points out that eval statements are supported by JavaScript, Python, PHP, and Ruby. But when the article describes recursion as "more forgotten than forbidden," it begs the inevitable question. Are you using these "forgotten code constructs" -- and should you be?
Honest question: Am I not supposed to use recursion? Am I missing something?
How is goto return better than just return?
In C in particular, which is the ONLY place I'll use goto... i might have a pattern like something like...
{
a = malloc(something)
if malloc failed goto e1
b = malloc(something2)
if malloc failed goto e2
c = malloc(onemorething)
if malloc failed goto e3
open a file... if error happened goto e3
some other error happened goto e3
e3:
free (a)
e2:
free(b)
e3:
return;
}
The goto sequence cleanly handles the memory free. Obviously you wouldn't want to just return after the 3rd malloc failed.
It depends.
In some cases, you want to allow goto statements, for instance because they help manage failure handling without adding condition or exception constructs.
In some case, you want none of these gotos, because you are using processes or tools which are (partly or entirely) not compatible with them, and you need these tools to work more than you need gotos.
In some cases, you don't want recursivity because the contex does not favor them (think embedded SW with restricted stack size).
In some cases you want recursion because it makes code simpler and closer to the principles behind it, thus more maintainable.
In some cases, you want class-like constructs in C be don't want C++ because the legacy code, people involved, time alloted, or general context just does not allow you to rewrite the whole thing.
Etc.
Somebody will publish a paper entitled: "Class statement considered harmful." and he will be applauded as the new IT guru!
You should read "GOTO considered harmful" before you bash it.
"Most programmers have heard the adage "Never use goto statements", but few of today's computer science students have the benefit of the historical context in which Dijkstra made his declaration against them. Modern programming dogma has embraced the myth that the goto statement is evil, but it is enlightening to read the original tract and realize that this dogmatic belief entirely misses the point."
http://david.tribble.com/text/...
In the bad old days, all you had was goto, and every program looked like spaghetti. Now that we have if...then...else, loops, switch-case statements,
goto should only be used as a last resort (and every use should be justified). I've been a professional programmer for twenty years; last year I used goto *twice*.
And never forget https://xkcd.com/292/
I'm tired of this mentality. I'd rather we favored those with skill rather than those with a lack of it. We as a people would go much farther.
Do you cripple the use of bicycles by forcing everyone to ride with training wheels? Or do we in fact favor those who can ride and instead burden the new-comer with the difficulties around obtaining and installing training wheels on very poor low-end bicycles?
Why should coding be any different? Sometimes people craft very complex and difficult pieces of software that tie together more than 20 libraries all which have their own quirks. I need the ability to share raw pointers, I need the ability to avoid ref-counting or shared_ptrs. I need to sometimes work with systems that have their own scheduler (Erlang, cough) and then bind C libraries into that ecosystem which doesn't allow blocking for more than 1ms. So I need crazy thread logic sometimes and odd code to support linking two separate mutex idioms from 2 different libraries so the lock works across the boundry....
Sometimes I just wish to be left alone in a complex space where another soul's mere presence is essentially proof of their abilities and understanding of logic. Similar to how adults sometimes wish to leave behind children and mingle only with other mature adults, I desire this of a programming language. Something to scare away all the posers and poor misguided (but righteous and well meaning) individuals.... It's not elitist thinking just like Adults aren't really being rude when trying to mingle with other like-minded adults.... it's more of a time-saver for people who find that many "adults" are actually children in disguise and only after 30 minutes of talking can you determine they are fake. I grow tired of wasting my time and eventually wish to move to a place where it's harder for the fake to blend in. It was amazing going from finding 1-2 good people every 50 to instead finding 1-2 good every 10.
For me that language has been C++ and simply put it's the most amazing thing I've ever discovered in my programming career. I also love how everyone still is scared to death of it and clamoring for it's deprecation while simultaneously using programs written in C++ to post these complaints.
Goto is considered harmful for humans. Who cares what happens under the covers. Hot liquids are harmful for humans. The fact that there are hot liquids under the covers when you drive your car is irrelevant.
But the entire modern GUI API is based on "event driven" programming. Replete with "OnRightButtonDown()" , "OnWindowClose()" ... . These are nothing but COMEFROM statements. COMEFROM could be as harmful or even more harmful than GOTO. With a good design based on a valid state machines and object oriented code we not only handle these with east, we are successfully developing incredibly complex code.
So, no. We did not forget GOTO just because some authority figure railed against it. We replaced it with a better concepts like event loop, event dispatching, object orientation.
sed -e 's/Chuck Norris/Rajnikant/g' joke > fact
goto is vital to safe C code. You want to be able to jump to your clean-up code from each place something might go wrong. The alternative is to add another layer of indentation under an "if" for each place something might go wrong, the stuff of nightmares.
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