Related
iam new to programming and i have been taking cs50,so in lecture one prof.david said that "you should always start reading the errors displayed from top".So i don`t understand what that suppose to mean.can anyone tell me why did he said that.
I think the propper method should be: first focus on last or biggest errors, isolate possible causes, test solutions independently and then integrate it all.
Also you should use SOLID principles to find and repair errors easier. Is a tough matter but is the best approach.
I think some articles can change the world. What is your best article about programming?
How to Ask Questions the Smart Way
(and you better make this into a community wiki, or it will get closed faster than you can blink :p )
The first one that comes to mind is Edsger Dijkstra's "Goto statement considered harmful".
Closed. This question is opinion-based. It is not currently accepting answers.
Want to improve this question? Update the question so it can be answered with facts and citations by editing this post.
Closed 7 years ago.
Improve this question
I've come across an article that discusses the issue of "code admiration". Basically, the author talks about how developers should be more skeptic about code they write. How we may "admire" our code too much, attach our-self to it, making us more vulnerable to bugs and other mishaps that may be lying in front of us.
How do you feel about this issue? And do you have more tips on how to avoid/be more aware of this issue?
Some years ago, I was working with another on a small "hobby" project, and I realised that we had to re-assess things. We had written lots of code but it wasn't all good code.
We didn't really want to "throw away" all the work we had put in. But I realised something: what mattered most was the amount of work we would need to put in from now on.
We couldn't change the fact that we had already put so much work into the project, so the only way to minimise the total amount of work the project would need, would be to minimise the amount of work we hadn't done yet.
Since that day, I have stopped being attached to my code. If I'm confident that throwing it away and starting from scratch means less work than keeping it and adapting it to my needs, then I'll throw it away.
My high school art teacher used to encourage us to take what we considered to be our best drawings and tear them up; he called this "cleansing the soul". His reasoning was that, as artists, we were driven to create works of art, and any time we produced something that we liked and that gave us satisfaction, our motivation to continue creating would be lessened.
So I followed his advice and tore up my best stuff, and it worked. Instead of spending my time admiring my old work, I created new stuff and continually got better. I've tried to follow the same principle with my code, but it doesn't really work: my computer has a tough plastic shell that is nearly impossible to tear through.
I post a fragment from Jeff Atwood's blog, Sucking Less Every Year, and I agree 100%.
I've often thought that sucking less
every year is how humble programmers
improve. You should be unhappy with
code you wrote a year ago. If you
aren't, that means either A) you
haven't learned anything in a year, B)
your code can't be improved, or C) you
never revisit old code. All of these
are the kiss of death for software
developers.
We sure like to admire our nice code, but it's not always easy to know what to admire. Complicated and elaborate code is sometimes mistaken for admirable code, while elegance and simplicity should rather be what to strive for.
Two quotes come to mind:
"Debugging is twice as hard as writing
the code in the first place.
Therefore, if you write the code as
cleverly as possible, you are, by
definition, not smart enough to debug
it.”
-- Brian Kernighan
and
"Make everything as simple as
possible, but not simpler."
-- Albert Einstein
Jonathan Edwards wrote an impressively beautiful essay on this subject, prompted by the work on the O'Reilly book Beautiful Code. Here's the final paragraph, but the rest of the essay is also worth reading.
Another lesson I have learned is to distrust beauty. It seems that infatuation with a design inevitably leads to heartbreak, as overlooked ugly realities intrude. Love is blind, but computers aren’t. A long term relationship – maintaining a system for years – teaches one to appreciate more domestic virtues, such as straightforwardness and conventionality. Beauty is an idealistic fantasy: what really matters is the quality of the never ending conversation between programmer and code, as each learns from and adapts to the other. Beauty is not a sufficient basis for a happy marriage.
Other versions of this same wisdom exist in other fields. Samuel Johnson, about writing:
Read over your compositions, and wherever you meet with a passage which you think is particularly fine, strike it out.
William Faulkner's version of this was much more succinct: “Kill your darlings.”
My father-in-law works as a film editor, and he studiously avoids the set where the film is being shot. When he does have to visit, he shields his eyes as much as he can. This is because when he decides whether or not to include a scene in the final film, he doesn't want to be influenced by how much effort it took to shoot the scene. What matters is how well the scene works in the final film.
My essay, "My evolution as a programmer" (which I would link to if I weren't a new user), is largely about learning skepticism about the code I'd written: whether it works, whether it's useful, whether it's comprehensible (pair programming was a real wake-up call here). It's hard!
I never admire my code. I admire other peoples code that i "borrow" and try and emulate them or better them and i find that the more i know, especially about coding the more i find i don't to know. The only thing of value wold be for peer programmers to admire my code and borrow it.
I think he has a good point. It's frustrating to work with people that have too much of this, as it really hinders teamwork and getting to the best solution to the problem.
As I can be a bit delusional, I try to put practices in place that will keep me grounded in reality. For code,
unit tests: These keep me more focused on what the code is supposed to do, as opposed to any abstract "beauty".
shared code ownership: There are two camps here: give people more ownership of their code and hope pride takes over, or give them less and let peer pressure come into play. I believe that giving people more ownership can lead to this code admiration. We practice shared code ownership, so I am constantly forced to see someone rewrite my perfect code to make it better (in their mind). I quickly realized admiring it too much was a waste of time and emotionally difficult.
pair programming: working side-by-side with someone will keep you realistic.
other feedback: These are all feedback loops, but there are others. There's no better way to see if something works than by watching someone (try to) use it. Put your work in front of as many people as possible. Have code reviews. Read other people's code. Run static code analysis tools.
I'm with PurplePilot - I don't admire my own code, and as such I'm constantly searching for new, more efficient (hell, easier) ways of doing the same thing. I like the Effective c# book, picked up lots of useful code from there that I admire.
I would have no hesitation about throwing code away and starting again, but not necessarily from scratch, i.e. by writing some code for a specific scenario and then throwing it away, you'll probably have a better grasp of the scenario. In other words, it's a "wicked problem", or you've found another way that doesn't work a la Edison.
It begs a wider question: if code isn't thrown away, or at least revisited, is developing on libraries that are becoming stagnant a good thing?
There is nothing wrong with admiring your code ... this is part of the positive reinforcement process that will motivate you to write more and better code in the future.
However, misplaced or misused admiration can be a problem. If the code is really not good, or has bugs that haven't been exposed by unit or other testing, or needs refactoring/redesign/replacement then this misplaced admiratoin is a problem. And using admiration as an excuse to skip part of the process - such as code reviews, or not having a skeptical attitude towards code - is misuse of admiration.
Like anything else that is good, admiration of code can be misplaced or misused - it doesn't mean that it in itself is bad. That would be like saying "religion is a bad thing, because it causes conflicts and wars between people".
Two words: code review.
Gather two or more fellow developers and invite them to review/criticize/comment on your code. 'twill shed some (admittedly harsh) light on your code.
It's perhaps better to have a healthier perspective - we aren't rocket scientists, and we aren't curing cancer - it's just work.
(Yes, it's reasonable to be proud of an entire building you helped build if you're an architect, but do they really have a lot of their self-esteem wrapped up in an individual blueprint, or a closet on floor 3 they designed by themselves?).
I need a calendar-widget for my website. This calendar needs to be very flexible. An option is to write it from scratch, but I think, if kept at a reasonable price, it would be a better option to buy the code.
So far I've come up with Web2Cal which looks great. I downloaded the free-version, to see how it would be to work with, but I feel like I'm running short on documentation. Does anyone have any experiences with this 'widget'? Is it worth spending some dollars on it?
Double bonus question:
Do you know of any better place to find documentation on Web2Cal than their primary website?
Do you know of similar tools, which you liked (commercial or free-to-use)?
Thanks in advance :)
[EDIT] If it makes any difference, the server code is being done i ASP.NET.
Did you try daypilot.org? that has a component for .NET
Web2Cal is certainly nice, I noticed that their support system is nice. They respond to all questions. Web2Cal is more flexible.
If you feel daypilot satisfies your needs go for it.
For some reason, I feel web2cal is more easy to customize and versatile than daypilot. To make up for the documentation, their support is pretty good. I guess that is true for all new softwares. So take advantage of that feature, post like 300 questions to them to get your work done.. ! saves you a whole lot of headache.
Closed. This question is opinion-based. It is not currently accepting answers.
Want to improve this question? Update the question so it can be answered with facts and citations by editing this post.
Closed 8 years ago.
Improve this question
I have always been astonished by Wine. Sometimes I want to hack on it, fix little things and generally understand how it works. So, I download the Wine source code and right after that I feel overwhelmed. The codebase is huge and - unlike the Linux Kernel - there are almost no guides about the code.
What are the best-practices for understanding such a huge codebase?
With a complex code base the biggest mistake you can make is trying to be a computer. Get the computer to run the code, and use a debugger to help find out what is going on.
Figure out how to compile, install and run your own version of Wine from the existing source code.
Learn how debug (e.g. use gdb) on a running instance of your version of Wine.
Run Wine under the debugger and make cause it to demonstrate the undesired behaviour.
The fun part: find where the code execution path goes and start learning how it all goes together.
Yes, reading lots and lots of code will help, but the compiler/debugger/computer can run code a lot faster than you.
A professor once told us to compare such a situation with climbing a mountain. You might be listening to someone who did this and tells you what it's like to look out into the country. And you believe without hesitation that that's a spectacular sight.
However, you have to start climbing yourself for real understanding what the view from the top is like.
And it's not that important to climb all the way to the top. It might be perfectly suficient just to reach a fair height above ground level.
But don't ever be afraid of start climbing. The view is always worth any efforts.
This has always been a nice analogy for me. I know this question was more about specific tips on how to efficiently deal with code bases once you started climbing. But nevertheless it instantly reminded me of our physics classes way back then.
(This is an answer I posted to a question a while back. I modified it a bit to fit this question.)
Experience has shown me that there are 3 major goals you have when learning a legacy system:
Learn what the code is supposed to do.
Learn how it does them.
(crucially) Learn why it does them the way it does.
All three of those parts are very important, and there's a few tricks to help you get started.
First, resist the temptation to just ctrl-click (or whatever your IDE uses) your way around the code to understand everything. You probably won't be able to keep everything in perspective in your mind this way, especially when each line forces you to look at multiple other classes in order to understand what it is, so you need to be able to hold several levels of the stack in your head.
Read documentation where possible; it usually helps you quickly gain a mental framework upon which to build everything that follows.
Run test cases where possible.
Don't be afraid to ask someone who knows if you have a question. Granted, you shouldn't waste others' time with inane queries, but if there's something that you simply don't understand (this is especially true with more conceptual questions like, "Wouldn't it make much more sense to implement this as a ___" or something), it's probably worth finding out the answer before you mess something up and don't know why.
When you do finally get down to reading the code, start at a logical "main" place and go from there. Don't just read the code top to bottom, or in alphabetical order, or anything (this is probably obvious).
The best way to get acquainted with a large codebase is to dive in. Many projects have a list of easy tasks that need to be done, and they're usually reserved to help ease people in. You should find and work on some of these; you'll learn a lot about the general code outline and structure, contribute to the project, and get an easy payoff that will help encourage you to take on larger tasks.
Like most projects, WINE has good resources available to its developers; IRC, wiki, mailing list, and guides/overviews. With most daunting codebases, it's not so scary after the first few fixes. WINE is truly large, and much like the kernel, I doubt there's any expert in all systems; don't feel like you need to be either. Start working on something that matters to you and take it from there.
I've started a few patches to WINE myself, and it's a good community and good structure. There's lots of very helpful debug messages, and it's a really cool project to work on, so that helps you hit it longer too.
We all appreciate your valor and willingness to help with WINE (it needs it). Thanks, and good luck.
Dig in. Think of a question you'd like to have answered, and try to find the answer. When you get tired of reading code, go read the dev mailing list, the developer's guide, or the wiki.
Unfortunately, there's no royal road to understanding a large code base. If you enjoy that sort of thing (I do) you're in for some fun. If not, guide books won't really help, so you aren't really that much worse off.
Look for one peculiar feature you are interested to improve. Search for its implementation. Once you found it, pull on that straw and all the rest will follow.
The best way is through comments.
I'm being ironic, as you understand tiny bits of the beast add comments so you can follow your trail.
The other developers will also enjoy it if you add the missing guides in the code.
Try to implement some tiny little change in the code, something that will be visible to you. That might be figuring out a workable way to output debugging statements (and figuring out where the output appears), it might be changing the default size of windows or desktop color, or something. Once you can make something happen in the codebase, you've scratched the surface of understanding and can begin to move on toward more complicated things. At that point, select a goal of something slightly more useful that you'd like the code to do, and implement that. Or check out the project's bug tracker and look for something small to start with.
Document as you go, and write unit tests as you go, and refactor as you go. When you figure out what a routine does, comment it!!
As others have suggested, dig in! Read all the available documentation you can absorb. Then see if you can find other people who are interested or knowledgeable and learn with/from them. It helps to have people to bounce ideas off of and ask questions.
For C source code, once you get a feel for what areas of the code you'd like to work on, generate ctags and cscope databases for that code. These tools make it a lot easier to jump around and understand the code. Many text editors (one example is gvim) have support for ctags and cscope so you can jump around easily.
(warning: shameless marketing ahead)
For Java developers using Eclipse, there's nWire. It is an Eclipse plugin for navigating and visualizing large codebases.
A good way to understand a large system is to break it down into it's constituent parts and focus on a specific paths through the application.
Your debugger is your friend here, set a breakpoint in the thread you want to investigate then step through it line by line looking at which each part does... hope that helps...