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Closed 9 years ago.
Not sure if this is the best place to ask or not but if it gets closed down oh well. I am in computer programming and starting on my first work term. I will be doing 2D game programming for iPhone in objective C. I was just wondering if you had any tips for learning how the code works on a big project. In college I have never worked with something in terms of this scope. I am used to a project with maybe a dozen source files while what I'll be working on has hundreds. It is very overwhelming for me.
Any Tips would be appreciated. Thanks very much
This is how I do it. Opinions and methods may vary.
Generally speaking, I find the best way to learn about a system is to go through the code while the app is running.
Pick a significant place in the UI (the startup screen, some other screen).
Find the class for that view. Generally just ask a senior developer. Developers are happy to give a pointer (no pun intended) to someone who wants to learn by himself instead of having to explain everything.
Place a breakpoint in that class and run the app in Xcode until you hit your breakpoint.
Then start tracing in there to see how things happen.
Repeat the process at different spots in the app and soon you'll get a general idea of how the app works. Then it's a lot easier to catch the details.
If the system is really enormous (like an enterprise app that runs on multiple systems), then a diagram showing all the architecturally significant pieces would probably help. For an iOS app, it's probably not needed.
Good luck...
I am a 3rd year computer engineer who has done four work terms, and I can offer the following :
Some general advice:
Compartmentalizing your approach is still very useful on a big project, as in a small one. The more specific parts you focus on at a time, the easier it will be to understand them. This is not always practical due to interdependence of programs, but it is still possible to, say, work on the graphics portion alone, or the character's movement algorithm, etc. You should know that in the past that it was possible for an educated person to know the sum of human knowledge, but that is impossible today. Even senior engineers/programmers have specific areas of expertise, and other areas where they are fuzzy. Find what you most enjoy/are talented at, and devote time to that.
A basic foundation is important. Study the basic ideas of loop structures, classes, methods and the like, and know them like the back of your hand, so when applying them across languages/platforms, all you need to do is refresh yourself on the syntax. The same basic ideas apply across a range of languages.
Most of all, do not panic. It is your first work term, and you are assigned mentors/supervisors, as well as working with a team. Doing it alone would be difficult, so network well with your teammates/superiors so you can all learn from each other, divide the work, and lessen the stress on yourself!
Good luck! :)
Short Answer :
Read less, do more, then read when you get stuck. In my opinion, that's the best way to learn any new language and also someone said :
"We learn by doing, there is no other way".
Long Answer :
Rule 1: Relax.
Rule 2: You gotta understand that this is not easy stuff to master. That is why people who do get paid really well. If you had an idea you could bang this stuff out in a couple of weeks with you need to dump that. Plan to spend months working up on it.
Rule 3: Understand that the Apple API is HUGE and it is always evolving. There is enough content to learn something new Everyday.
Rule 4: The fewer programming languages you've had to learn, the harder it is to learn new ones. You will learn slower than someone else who has learned half dozen languages/APIs already.
Rule 5: Don't be afraid to use repetition and brute force. I think the thing that slows novices down is not learning the behaviors and methods of common foundation classes like NSString, NSArray, NSDictionary etc.
Rule 6: As a learning exercise, copy-pasting might not be the right thing to do. If there's an Apple example of how to do something, rather than copy-pasting I tend to rewrite it manually. I find it sticks better in my mind.
Rule 7: Use any resources you like. There are no rules on how you should learn.
Rule 8: iPhone is a memory constrained device where network and local storage access is slow. Parts of your application can be unloaded at any time, your application is responsible for maintaining it's memory footprint (not the user), and an event (phone call, memory, etc.) may require the app to respond accordingly and quickly.
Rule 9: It isn't about you. It isn't about your code. And it isn't about your code doing this or that. It's first about the user and responding to the user. It's second about your code responding to the framework. You don't usually tell the framework what to do. It asks you for things when it needs something. You sit and wait for it to talk to you. You're not in charge. You don't control the runloop; it controls you. You register to be told when things happen, and you indicate that you're the object who knows something about something (data for a table for instance). And then you let go, and let Cocoa do the rest. It's a very different world. I like it very much.
Rule 10: Relax.
When I'm coming to a new Xcode project, I open it up in OmniGraffle Pro. If the project is well organized, you'll see a nice diagram with a summary of the classes, the methods that are present and a little bit of how things relate to each other, important enums to know about, and other helpful information for getting a good overview of the project.
After that, pick a point like #mprivat said and run it in the debugger and get a feel for how things run. I like to set breakpoints with logs of the breakpoint name and hit count (and maybe the value of some variable or parameter if it seems relevant) and automatic continue after a little while to avoid pesky timing issues that can sometimes creep up when the debugger pauses execution. I use breakpoint logging so I don't have to worry about accidentally committing clutter code. (Be careful of pulling new code though because breakpoints don't move with your changing codebase. :))
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Closed 11 years ago.
I recently came into some blogs saying that Linq to Sql is dead. and a few days ago I saw a discussion with some people saying that Silverlight maybe will take ASP.net place! ...I don't want to ask if they are true or not but it is so annoying when you wake up and found your languages and informations in the casket! (I think that Microsoft languages have the big part of this words). So what should I do in this case ? drop every thing back and start again with the new techniques or keep using the old stuff or what ?
A platform isn't dead because someone says it's dead. It's dead when it's no longer used, and in that case, it's obvious you shouldn't be using it either. Unless, of course, you're employed by a big company that has a big legacy system that needs further development using that "dead" technology.
Nothing ever really dies. Especially Microsoft stuff. I thought I had wasted 10 years as a FoxPro dev (not even VFP!), but this helped me get jobs, even in related technologies like dBASE and Clipper, since those skills are harder to find.
Having said that, by all means keep up with the mainstream. Continuous learning is expected in this field.
In any case, neither of those claims (re Linq to Sql and Silverlight) is true.
First off, dont immediately jump to the assumption that what you read in a blog or in a tech magazine is true. If the 'old stuff' still works, whats the compelling reason to change? Basically its just keeping up with fashion. Use what you want to use. If you understand the basics of programming, you can adapt as needed when presented with new technologies.
Neither ASP.NET or Linq-to-SQL appear to be vanishing any time soon; however, this advice always applies:
Put pressure on Microsoft (or any other vendor, for that matter) to support products your business depends on.
If your business regularly purchases upgrades to its Microsoft stack, MS will want to make you happy. Get involved at Microsoft Connect, contact your MS representative, and be involved. The safest path to maintaining support from MS is by participating in their process. (It's why Windows XP remained supported long after MS announced support would end.)
Simple answer: Be sufficiently broad in your technical abilities.
As a hiring manager, I'm more concerned that you know how to write good programs and that you know how to get answers to your questions, than I am that you spent 10 years focusing on a specific technology.
For example: If I'm hiring for an MVC2 position, I would gladly take a seasoned Microsoft web developer with webforms experience and some MVC2 exposure over an unseasoned and unskilled programmer that's been working in MVC2 since it came out.
Many programmers are keen to try out new things. The statement "Technique X is dead", means just that someone tries to convince himself or a group, that investing more time into something else seems worthwhile.
To really kill a technology you would need to remove all related downloads and available knowledge or relicense the software in some form that makes usage impossible.
When a group of people shout that X is dead, they are just moving to Y. If you can still hire X programmers, you are not in big trouble.
Don Box once said "If your this kind of people that start working with a technology when it's dead, it time for you to start using COM". He said that to introduced .net an confirm that way that COM won't be further improved. See ? "Dead" means it won't evolve as much as other anymore but definitely not that we should't use anymore.
Don't jump to conclusions based on (non-authoritative) blogs. People have opinions, and that's all they are. Until the vendors of the technologies you're using come out and say it, proceed with caution.
I'm not a .Net expert by any means but I think there's a reason for not using Linq for SQL queries since a dedicated ORM approach will most likely be faster and more configurable. As far as Silverlight, it's just a subset of WPF which is a GUI framework. They possibly wish that silverlight would take over some processing from the server side but I doubt they'll get that sort of market penetration.
That's life on the cutting edge... You got into this business because you liked the latest technology, right? Well, don't look back, look forward. Before your favorite technology even has the sniffles, you should be looking at what's going up. If you study up on the latest technology, you won't even notice when the old stuff go away.
Software development is all about learning things so that you can build things that will be thrown away and replaced with newer things some day! If you don't want to commit to continuous change, you're in the wrong field! :-)
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Closed 10 years ago.
As an artist and musician, I often want to sit down and just let the code roll like a piece of free-form poetry, but I've found that doesn't work as well as when I have a set goal in mind. I've been experimenting lately with setting up tiny, fun goals for myself, not unlike how an artist would sketch a quick still-life, but I wonder...
What do others do when they want to code for fun, without the bondage of an already-committed project?
Design work, I find, flows much easier than just coding. I find that coding is often more of just implementation of a good design; I really like to just sit down with a pad of paper and a pen (and likely a bottle of wine) and work out an interesting design.
Project Euler is where I'm having fun at now. I can go at my own pace and work on the problems that interest me. Also, work in any language I choose.
Write documentation when coding doesn't come easy - coding will quickly seem much more appealing!
Going for a walk outside.
I tend to map my idea or build a structure in a MindMapping tool like MindMeister. And it's great for a team because it can be edited in real time by multiple persons!
I like to pick up a new language and learn how to express ideas in it. This usually has the benefit of showing me what I like and don't like about the languages I currently use. I usually pick some little tool project I've been wanting to do. Using the new language angle get's me motivated
My most recent 'new language' is Scala, in this case it will likely become a langue I use.
I like writing on whiteboards. Great for db diagrams, task lists, feature lists, (other lists,) random ideas, notes, etc. (db diagrams being the biggie for me)
Python is great for just getting things going on an idea and having the language (usually) behave like you would expect.
While it may have its drawbacks, it sounds like a great fit for what you are describing.
So to answer your question, the Python Challenge is entertaining and often gets me thinking about little things that would be fun to code, probably because it exposes you to different types of problems.
I like to code.
I like to find something interesting, code it and then see it works.
It does not have to be a project per see, it's good enough if it does something, like use Google api to get picasa albums, change song in iTunes or get details of current iTunes song, automate downloading of document from web site that is behind login and requires cookies and all that stuff, data parser in python, simple app on Mac, core data application, google codejam problems, topcoder.com problems ...
I like to learn new features of some language or some new language/technology/patterns/tool :-)
Usually I will work in Photoshop for a while. Get creative and try to come up with a new design that's not constrained by any code. Maybe even find something inspiring on the web for some new design ideas... then try to implement the design in code. That's the fun and challenging bit.
Use the REPL.
You figure out broadly the sort of thing you need to do - what APIs you need to use, what data structures you need to handle - and then prod them interactively until they start making sense. A ton of languages I use now have REPLs: Ruby, Python, Scala, Java (BeanShell, or JRuby/Jython etc.), C# ('csharp'), PHP (Facebook have made a REPL for it), Smalltalk (GNU gst) and, obviously, LISP/Scheme.
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Closed 10 years ago.
With the interest of creating a roguelike RPG (such as Nethack, Rogue, and ADOM), which programming language would be most suitable and why?
With the language that you choose, be sure to list any libraries or facets of the language that make it particularly well-suited.
Way back in the day I tried to write Roguelike games using QuickBASIC out of all things (it was 1988.) Not the recommended approach...
There are still some development circles out there. Here's an FAQ on Roguelike Development and also a blog dedicated to the same.
My language of use (I'm trying to create roguelike too) is Python, because:
It's high level programming language, I don't need to think about memory allocation all the time, etc, but keep my mind on algorithms.
There's tons of useful libraries for almost everything. Recently I've found TDL/libtcod which can be useful for roguelike development.
With bindings you can easily use C/C++ libraries or even write few critical functions in C/C++, and use them.
It's the most readable programming language I've ever seen.
While programming in Python I've learned to use internal documentation. It's very helpful thing, I just read my code few months later and I still know what it's doing.
That's a very personal choice as always :-)
I wrote my Roguelike game (Tyrant) in Java for the following reasons:
Very portable (even with graphics)
Garbage collection / memory management
Lots of good free / open source libraries available (helpful for algorithms, data structures and manipulating save game files etc.)
It's a statically typed language - this has performance and robustness benefits which I judged to be worth the additional coding complexity
I wanted to hone my Java skills more generally for use in other projects
EDIT: For those interested it is open source, all code is available at SourceForge
Well I've made a couple roguelikes in C, spending a fair amount of time at roguebasin, which is a great site for anything related to roguelike development.
As for what language you should use, I don't really see it making a huge difference. I pick C because of the portability, and a lot of libraries work well with it.. But an object oriented language can clean up some things that you may not want to keep track of.
There aren't any languages that I would consider to be specifically greater than the rest for roguelikes. If you're making it graphical, you may prefer something that has that built-in, such as flash / silverlight. But even then there are libraries for any other languages that bring them to about the same degree of difficulty in that regard.
So I'd say take a language you know and like, or that you don't know and want to learn..
Most of these answers are great, but there's something to be said for the combined power of object-oriented stuff and low-level commands that can be abused in C++. If you're looking for some inspiration, the C sourcecode to NetHack is widely available and documented well enough that you can certainly poke around to learn some things. That said, it's a huge project that's been growing for decades, and not everything is as clean as you're going to want things for your own project - don't get roped into making poor design choices based off of what you find in NetHack.
Honestly, though, in terms of what you use it probably doesn't matter at all - though I'd highly recommend using an OO language. There's so much crap to handle in a roguelike (heck, any CRPG really) that OOP is the easiest way of staying sane.
The original nethack was written in C, and the source is available if you want to get some ideas about how it was written, and the challenges you may find which might be a good way to start deciding on a language.
My first question would be whether the game is going to have a web based UI or be some kind of console/window affair like the original Rogue-like games? If the former I would say that any language you're comfortable with would be a good choice. Ruby on Rails, Python/Django, PHP/CakePHP, etc. would all be great.
But if the answer is the latter, this is a game that you want people to be able to download and install locally, I'm going to go with Java. It's a great language with no memory management for you to deal with. It achieves very high performance thanks to just-in-time compilation and optimization, and it has an extremely rich library to help you with data structures, Swing makes for some really beautiful UIs, and the 2D library allows for the most rich cross-platform rendering outside of PostScript. It also has the availability across Windows, Mac OS X, and Linux that you're not going to get from some other choices.
Finally, distribution of your application is easy via Java Web Start as well, so people can download and install the game with just a couple of clicks once they have Java and keep it on their machine to run as long as they like.
For making any game, any language will be right if :
you can use it (you are able to use it, by knowledge or if it's easy enough to learn right now for you or your team)
it produce applications that runs on your client's computer
it can easily produce applications that runs fast enough for your game's needs.
I think that for a Rogue-Like, any language you know will be right as far as it runs on you target. Performances are not really a problem in this kind of game. World generation can require high performance if your world generation is really complex though...
just go with something that will handle the low-level details for you. whatever you know should work.
hey, they can write one in javascript.
I recommend Actionscript for those games.
You could consider Silverlight.
It sits on top of C# and .Net so theres not much need to worry about memory management. With SL you'll get built in support for scene graph type rendering - culling of things not on screen, Key board, mouse events, clicks on objects etc.
There's an initial learning curve, but I find it's a great environment to work in.
I'm occasionally unfortunate enough to have to make alterations to very old, poorly not documented and poorly not designed code.
It often takes a long time to make a simple change because there is not much structure to the existing code and I really have to read a lot of code before I have a feel for where things would be.
What I think would help a lot in cases like this is a tool that would allow one to visualise an overview of the code, and then maybe even drill down for more detail. I suspect such a tool would be very hard to get right, given that is trying to find structure where there is little or none.
I guess this is not really a question, but rather a musing. I should make it into a question - What do others do to assist in getting their head around other peoples code, the good and the bad?
Hmm, this is a hard one, so much to say so little time ...
1) If you can run the code it makes life soooo much easier, breakpoints (especially conditional) break points are you friend.
2) A purists' approach would be to write a few unit tests, for known functionality, then refactor to improve code and understanding, then re-test. If things break, then create more unit tests - repeat until bored/old/moved to new project
3) ReSharper is good at showing where things are being used, what's calling a method for instance, it's static but a good start, and it helps with refactoring.
4) Many .net events are coded as public, and events can be a pain to debug at the best of times. Recode them to be private and use a property with add/remove. You can then use break point to see what is listening on an event.
BTW - I'm playing in the .Net space, and would love a tool to help do this kind of stuff, like Joel does anyone out there know of a good dynamic code reviewing tool?
I have been asked to take ownership of some NASTY code in the past - both work and "play".
Most of the amateurs I took over code for had just sort of evolved the code to do what they needed over several iterations. It was always a giant incestuous mess of library A calling B, calling back into A, calling C, calling B, etc. A lot of the time they'd use threads and not a critical section was to be seen.
I found the best/only way to get a handle on the code was start at the OS entry point [main()] and build my own call stack diagram showing the call tree. You don't really need to build a full tree at the outset. Just trace through the section(s) you're working on at each stage and you'll get a good enough handle on things to be able to run with it.
To top it all off, use the biggest slice of dead tree you can find and a pen. Laying it all out in front of you so you don't have to jump back and forward on screens or pages makes life so much simpler.
EDIT: There's a lot of talk about coding standards... they will just make poor code look consistent with good code (and usually be harder to spot). Coding standards don't always make maintaining code easier.
I do this on a regular basis. And have developed some tools and tricks.
Try to get a general overview (object diagram or other).
Document your findings.
Test your assumptions (especially for vague code).
The problem with this is that on most companies you are appreciated by result. That's why some programmers write poor code fast and move on to a different project. So you are left with the garbage, and your boss compares your sluggish progress with the quick and dirtu guy. (Luckily my current employer is different).
I generally use UML sequence diagrams of various key ways that the component is used. I don't know of any tools that can generate them automatically, but many UML tools such as BoUML and EA Sparx can create classes/operations from source code which saves some typing.
The definitive text on this situation is Michael Feathers' Working Effectively with Legacy Code. As S. Lott says get some unit tests in to establish behaviour of the lagacy code. Once you have those in you can begin to refactor. There seems to be a sample chapter available on the Object Mentor website.
I strongly recommend BOUML. It's a free UML modelling tool, which:
is extremely fast (fastest UML tool ever created, check out benchmarks),
has rock solid C++ import support,
has great SVG export support, which is important, because viewing large graphs in vector format, which scales fast in e.g. Firefox, is very convenient (you can quickly switch between "birds eye" view and class detail view),
is full featured, intensively developed (look at development history, it's hard to believe that so fast progress is possible).
So: import your code into BOUML and view it there, or export to SVG and view it in Firefox.
See Unit Testing Legacy ASP.NET Webforms Applications for advice on getting a grip on legacy apps via unit testing.
There are many similar questions and answers. Here's the search https://stackoverflow.com/search?q=unit+test+legacy
The point is that getting your head around legacy is probably easiest if you are writing unit tests for that legacy.
I haven't had great luck with tools to automate the review of poorly documented/executed code, cause a confusing/badly designed program generally translates to a less than useful model. It's not exciting or immediately rewarding, but I've had the best results with picking a spot and following the program execution line by line, documenting and adding comments as I go, and refactoring where applicable.
a good IDE (EMACS or Eclipse) could help in many cases. Also on a UNIX-platform, there are some tools for crossreferencing (etags, ctags) or checking (lint) or gcc with many many warning options turned on.
First, before trying to comprehend a function/method, i would refactor it a bit to fit your coding conventions (spaces, braces, indentation) and remove most of the comments if they seem to be wrong.
Then I would refactor and comment the parts you understood, and try to find/grep those parts over the whole source tree and refactor them there also.
Over the time, you get a nicer code, you like to work with.
I personally do a lot of drawing of diagrams, and figuring out the bones of the structure.
The fad de jour (and possibly quite rightly) has got me writing unit tests to test my assertions, and build up a safety net for changes I make to the system.
Once I get to a point where I'm comfortable enought knowing what the system does, I'll take a stab at fixing bugs in the sanest way possible, and hope my safety nets neared completion.
That's just me, however. ;)
i have actuaally been using the refactoring features of ReSharper to help m get a handle on a bunch of projects that i inherited recently. So, to figure out another programmer's very poorly structured, undocumented code, i actually start by refactoring it.
Cleaning up the code, renaming methods, classes and namespaces properly, extracting methods are all structural changes that can shed light on what a piece of code is supposed to do. It might sound counterintuitive to refactor code that you don't "know" but trut me, ReSharper really allows you to do this. Take for example the issue of red herring dead code. You see a method in a class or perhaps a strangely named variable. You can start by trying to lookup usages or, ungh, do a text search, but ReSharper will actually detect dead code and color it gray. As soon as you open a file you see in gray and with scroll bar flags what would have in the past been confusing red herrings.
There are dozens of other tricks and probably a number of other tools that can do similar things but i am a ReSharper junky.
Cheers.
Get to know the software intimately from a user's point of view. A lot can be learnt about the underlying structure by studying and interacting with the user interface(s).
Printouts
Whiteboards
Lots of notepaper
Lots of Starbucks
Being able to scribble all over the poor thing is the most useful method for me. Usually I turn up a lot of "huh, that's funny..." while trying to make basic code structure diagrams that turns out to be more useful than the diagrams themselves in the end. Automated tools are probably more helpful than I give them credit for, but the value of finding those funny bits exceeds the value of rapidly generated diagrams for me.
For diagrams, I look for mostly where the data is going. Where does it come in, where does it end up, and what does it go through on the way. Generally what happens to the data seems to give a good impression of the overall layout, and some bones to come back to if I'm rewriting.
When I'm working on legacy code, I don't attempt to understand the entire system. That would result in complexity overload and subsequent brain explosion.
Rather, I take one single feature of the system and try to understand completely how it works, from end to end. I will generally debug into the code, starting from the point in the UI code where I can find the specific functionality (since this is usually the only thing I'll be able to find at first). Then I will perform some action in the GUI, and drill down in the code all the way down into the database and then back up. This usually results in a complete understanding of at least one feature of the system, and sometimes gives insight into other parts of the system as well.
Once I understand what functions are being called and what stored procedures, tables, and views are involved, I then do a search through the code to find out what other parts of the application rely on these same functions/procs. This is how I find out if a change I'm going to make will break anything else in the system.
It can also sometimes be useful to attempt to make diagrams of the database and/or code structure, but sometimes it's just so bad or so insanely complex that it's better to ignore the system as a whole and just focus on the part that you need to change.
My big problem is that I (currently) have very large systems to understand in a fairly short space of time (I pity contract developers on this point) and don't have a lot of experience doing this (having previously been fortunate enough to be the one designing from the ground up.)
One method I use is to try to understand the meaning of the naming of variables, methods, classes, etc. This is useful because it (hopefully increasingly) embeds a high-level view of a train of thought from an atomic level.
I say this because typically developers will name their elements (with what they believe are) meaningfully and providing insight into their intended function. This is flawed, admittedly, if the developer has a defective understanding of their program, the terminology or (often the case, imho) is trying to sound clever. How many developers have seen keywords or class names and only then looked up the term in the dictionary, for the first time?
It's all about the standards and coding rules your company is using.
if everyone codes in different style, then it's hard to maintain other programmer code and etc, if you decide what standard you'll use have some rules, everything will be fine :) Note: that you don't have to make a lot of rules, because people should have possibility to code in style they like, otherwise you can be very surprised.
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I've never written functional specs, I prefer to jump into the code and design things as I go. So far its worked fine, but for a recent personal project I'm writing out some specs which describe all the features of the product, and how it should 'work' without going into details of how it will be implemented, and I'm finding it very valuable.
What are your thoughts, do you write specs or do you just start coding and plan as you go, and which practice is better?
If you're driving from your home to the nearest grocery store, you probably don't need a map. But...
If you're driving to a place you've never been before in another state, you probably do.
If you're driving around at random for the fun of driving, you probably don't need a map. But...
If you're trying to get somewhere in the most effective fashion (minimize distance, minimize time, make three specific stops along the way, etc.) you probably do.
If you're driving by yourself and can take as long as you like, stopping any time you see something interesting or to reconsider your destination or route, you may not need a map. But...
If you're driving as part of a convoy, and all need to make food and overnight lodging stops together, and need to arrive together, you probably do.
If you think I'm not talking about programming, you probably don't need a functional spec, story cards, narrative, CRCs, etc. But...
If you think I am, you might want to consider at least one of the above.
;-)
For someone who "jumps into the code" and "design[s] as they go", I would say writing anything including a functional spec is better than your current methods. A great deal of time and effort can be saved if you take the time to think it through and design it before you even start.
Requirements help define what you need to make.
Design helps define what you are planning on making.
User Documentation defines what you did make.
You'll find that most places will have some variation of these three documents. The functional spec can be lumped into the design document.
I'd recommend reading Rapid Development if you're not convinced. You truely can get work done faster if you take more time to plan and design.
Jumping "straight to code" for large software projects would almost surely lead to failure (as immediatley starting posing bricks to build a bridge would).
The guys at 37 Signals would say that is better to write a short document on paper than writing a complex spec. I'd say that this could be true for mocking up quickly new websites (where the design and the idea could lead better than a rigid schema), but not always acceptable in other real life situations.
Just think of the (legal, even) importance a spec document signed by your customer can have.
The morale probably is: be flexible, and plan with functional or technical specs as much as you need, according to your project's scenario.
For one-off hacks and small utilities, don't bother.
But if you're writing a serious, large application, and have demanding customers and has to run for a long time, it's a MUST. Read Joel's great articles on the subject - they're a good start.
I do it both ways, but I've learned something from Test Driven Development...
If you go into coding with a roadmap you will get to the end of the trip a helluva lot faster than you will if you just start walking down the road without having any idea of how it is going to fork in the middle.
You don't have to write down every detail of what every function is going to do, but define you basics so that way you know what you should get done to make everything work well together.
All that being said, I needed to write a series of exception handlers yesterday and I just dove right in without trying to architect it out at all. Maybe I should reread my own advice ;)
What a lot of people don't want to admit or realize is that software development is an engineering discipline. A lot can be learned as to how they approach things. Mapping out what your going to do in an application isn't necessarily vital on small projects as it is normally easier to quickly go back and fix your mistakes. You don't see how much time is wasted compared to writing down what the system is going to do first.
In reality in large projects its almost necessary to have road map of how the system works and what it does. Call it a Functional Spec if you will, but normally you have to have something that can show you why step b follows step a. We all think we can think it up on the fly (I am definitely guilty of this too), but in reality it causes us problems. Think back and ask yourself how many times you encountered something and said to yourself "Man I wish I would have thought of that earlier?" Or someone else see's what you've done, and showed you that you could have take 3 steps to accomplish a task where you took 10.
Putting it down on paper really forces you to think about what your going to do. Once it's on paper it's not a nebulous thought anymore and then you can look at it and evaluate if what you were thinking really makes sense. Changing a one page document is easier than changing 5000 lines of code.
If you are working in an XP (or similar) environment, you'll use stories to guide development along with lots of unit and hallway useability testing (I've drunk the Kool-Aid, I guess).
However, there is one area where a spec is absolutely required: when coordinating with an external team. I had a project with a large insurance company where we needed to have an agreement on certain program behaviors, some aspects of database design and a number of file layouts. Without the spec, I was wide open to a creative interpretation of what we had promised. These were good people - I trusted them and liked working with them. But still, without that spec it would have been a death march. With the spec, I could always point out where they had deviated from the agreed-to layout or where they were asking for additional custom work ($$!). If working with a semi-antagonistic relationship, the spec can save you from even worse: a lawsuit.
Oh yes, and I agree with Kieveli: "jumping right to code" is almost never a good idea.
I would say it totally "depends" on the type of problem. I tend to ask myself am I writing it for the sake of it or for the layers above you. I also had debated this and my personal experience says, you should since it keeps the project on track with the expectations (rather than going off course).
I like to decompose any non trivial problems loosely on paper first, rather than jumping in to code, for a number of reasons;
The stuff i write on paper doesn't have to compile or make any sense to a computer
I can work at arbitrary levels of abstraction on paper
I can add pictures and diagrams really easily
I can think through and debug a concept very quickly
If the problem I'm dealing with is likely to involve either a significant amount of time, or a number of other people, I'll write it up as an outline functional spec. If I'm being paid by someone else to develop the software, and there is any potential for ambiguity, I will add enough extra detail to remove this ambiguity. I also like to use this documentation as a starting point for developing automated test cases, once the software has been written.
Put another way, I write enough of a functional specification to properly understand the software I am writing myself, and to resolve any possibile ambiguities for anyone else involved.
I rarely feel the need for a functional spec. OTOH I always have the user responsible for the feature a phone call away, so I can always query them for functional requirements as I go.
To me a functional spec is more of a political tool than technical. I guess once you have a spec you can always blame the spec if you later discover problems with the implementation. But who to blame is really of no interest to me, the problem will still be there even if you find a scapegoat, better then to revisit the implementation and try to do it right.
It's virtually impossible to write a good spec, because you really don't know enough of either the problem or the tools or future changes in the environment to do it right.
Thus I think it's much more important to adapt an agile approach to development and dedicate enough resources and time to revisit and refactor as you go.
It's important not to write them: There's Nothing Functional about a Functional Spec