If I could take ten software development books to a desert island, The Elements of Style by William Strunk and E.B. White would be one of them.
Of course, “Strunk and White,” as the book is commonly called, has nothing to do with software (it was written in 1935) and everything to do with writing: grammar, composition, and style for users of the English language. But in its 100 short pages this book has more to say about the craft of software than many books you’ll find in the “Computing” section of your local bookstore. All you have to do is replace a few key words throughout the text and presto! Pearls of software development wisdom, delivered in near-perfect English.
Like this one, which discusses the importance of proper software design.
2.12. Choose a suitable design and hold to it.
A basic structural design underlies every kind of writing programming. Writers Programmers will in part follow this design, in part deviate from it, according to their skills, their needs, and the unexpected events that accompany the act of composition. Writing Programming, to be effective, must follow closely the thoughts of the writer programmer, but not necessarily in the order in which those thoughts occur. This calls for a scheme of procedure….in most cases, planning must be a deliberate prelude to writing programming. The first principle of composition software development, therefore, is to foresee or determine the shape of what is to come and pursue that shape.
The last sentence is telling: the first principle of composition is to foresee or determine the shape of what is to come and pursue that shape. This is really what we’re doing when we build software. All of the rigorous development schedules, iterations, use cases, only serve to fill in the blank software canvas we’re presented with, in a way that (hopefully) creates working software in a timely fashion without going over budget. Of course, we can’t go with just any design for our applications; the design must suit the problem at hand.
5.3. Work from a suitable design.
Before beginning to compose develop something, gauge the nature and extent of the enterprise and work from a suitable design. Design informs even the simplest structure, whether of brick and steel or of prose. You raise a pup tent from one sort of vision, a cathedral from another. This does not mean that you must sit with a blueprint always in front of you, merely that you had best anticipate what you are getting into. To compose a laundry list, you can work directly from the pile of soiled garments, ticking them off one by one. But to write a biography, you will need at least a rough scheme; you cannot plunge in blindly and start ticking off after the fact about your subject, less you miss the forest for the trees and there be no end to your labors.
Some programmers take a very simple problem and needlessly complicate it with design overkill. Other programmers take a very complex problem and underestimate it; they just start coding. Both behaviors are equally deadly. There’s an appropriate design effort for every project, based on its intended functionality, and the difficulty or complexity of realizing that functionality. You don’t want to do too little design; equally, you don’t want to do too much. Instead, like Goldilocks, you want to choose the bowl of design porridge which is just right.
5.21. Prefer the standard to the offbeat
Young writers Inexperienced programmers will be drawn at every turn toward eccentricities in language. They will hear the beat of new vocabularies abstractions, the exciting rhythms of special segments of their society industry, each speaking a language of its own. All of us come under the spell of these unsettling drums; the problem for beginners is to listen to them, learn the words, feel the vibrations, and not be carried away.
This is a rule we Microsoft ecosystem programmers violate all the time, because the Microsoft technology avalanche amounts to a sort of de facto standard. So when Microsoft comes out with a new library, a new MFC or WPF, and says “use this!” we listen. The result is standard-but-not-quite-standard code which fares well in a Microsoft habitat (for five or ten years) but which creates a lot of work when we want to port or expose these same systems to other platforms. The same sort of problem affects, to a lesser degree, the sprawling Linux ecosystem. And it’s likely that both Microsoft and non-Microsoft approaches could be cleaned up by applying Occam’s Razor liberally:
2.17. Omit needless words code
Vigorous programming is concise. A function should contain no unnecessary statements, a statement no unnecessary expressions, for the same reason that a drawing should have no unnecessary lines and a machine no unnecessary parts. This requires not that the programmer make all functions short, or avoid all detail and treat subjects only in outline, but that every line of code tell.
Don’t unnecessarily multiply things! Don’t create arbitrary divisions between things! Damnit man! Things like: lines of code. Objects. Methods. Enumerations. Components. If you’ve ever looked at production source code for a major application or operating system, your initial reaction is likely to be one of shock: what the $!@$ is all this crap? This is a good reaction, not a bad one. Excess code turns software maintenance into a nightmare, because it exterminates clarity, and increases the amount of brain cycles required to achieve understanding of the code. Or as Strunk and White would say:
5.16. Be clear.
Clarity is not the prize in writing programming, nor is it always the principle mark of good style. There are occasions when obscurity serves a literary programmer yearning, if not a programming purpose, and there are writers programmers whose mien is more overcast than clear. But since writing programming is communication, clarity can only be a virtue.
Of course, clarity in software is arguably more important than clarity in writing, because the clarity of production code affects the dollar cost of producing and maintaining a piece of software. In other words, lack of clarity costs companies millions upon millions of dollars each and every year. And even though it’s important to:
5.2. Write Program in a way that comes naturally
Program in a way that comes easily and naturally to you, using words and phrases APIs and statements that come readily to hand. But do not assume that because you have acted naturally your product is without flaw.
It’s even more important that we:
5.9. Do not affect a breezy manner
The volume of writing source code is enormous, these days, and much of it has a sort of windiness about it, almost as though the author programmer were in a state of euphoria. “Spontaneous me,” sang Whitman, and, in his innocence, let loose the hordes of uninspired scribblers script kiddies who would one day confuse spontaneity with genius.
Give each line of code its due. If a particular function calls for the use of an unfamiliar API, learn the API rather than going the quick and dirty route. In Windows codebases you’ll often see someone spawning a process using LoadModule even though it’s deprecated. They do this because the recommended function, CreateProcess, takes a small army of parameters (ten, to be precise) whereas LoadModule takes two.
__in_opt LPCTSTR lpApplicationName,
__inout_opt LPTSTR lpCommandLine,
__in_opt LPSECURITY_ATTRIBUTES lpProcessAttributes,
__in_opt LPSECURITY_ATTRIBUTES lpThreadAttributes,
__in BOOL bInheritHandles,
__in DWORD dwCreationFlags,
__in_opt LPVOID lpEnvironment,
__in_opt LPCTSTR lpCurrentDirectory,
__in LPSTARTUPINFO lpStartupInfo,
__out LPPROCESS_INFORMATION lpProcessInformation
It’s always cheaper to code things correctly the first time, than it is to code them incorrectly and fix them later. On the other hand, code, like prose, is almost never perfect (or even adequate) in its first incarnation. That’s why it’s important to:
5.5. Revise Refactor and rewrite
Revising is part of writing. Refactoring is part of coding. Few writers programmers are so expert that they can produce what they are after on the first try. Quite often you will discover, on examining the completed work system, that there are serious flaws in the arrangement of the material, calling for transpositions.
If Strunk and White were alive today, they’d probably be big fans of Agile and other iterative, incremental development processes which a) emphasize simplicity and b) allow ample opportunity for stepwise improvement. Of course, we don’t need Agile (or Strunk and White) to tell us that it’s a good idea to:
2.17. Omit needless words code
Vigorous writing programming is concise. A sentence function should contain no unnecessary words code, a paragraph block of code no unnecessary sentences statements, for the same reason that a drawing should have no unnecessary lines and a machine no unnecessary parts. This requires not that the writer programmer make all functions short, or avoid all detail and treat subjects only in outline, but that every word line of code tell.
If there were ever such thing as a universal design criterion, simplicity would be it. And one of the main ways we achieve simplicity is by cutting out the stuff we don’t need. In the art world we have movements (such as the Baroque) which revel in complexity, and in writing we have expansive authors like Cormac McCarthy, but generally speaking, the simpler the writing/code/system/work of art, the better. Better because more intelligible; easier to maintain; and structurally more sound.
Young writers programmers often suppose that style is a garnish for the meat of prose code, a sauce by which a dull dish is made palatable. Style has no such separate entity; it is nondetachable, unfilterable. The beginner should approach style warily, realizing that it is an expression of self, and should turn resolutely from all devices that are popularly believed to indicate style — all mannerisms, tricks, adornments. The approach to style is by way of plainness, simplicity, orderliness, sincerity.
Speaking of structure:
2.19. Write Express coordinate ideas in similar form
This principle, that of parallel construction, requires that expressions similar in content and function be outwardly similar. The likeness of form enables the reader to recognize more readily the likeness of content and function.
Object-oriented programming makes the uniform expression of coordinate ideas relatively easy, using basic techniques:
- Generics / Templates
There are others, but every programmer is familiar with a typical class hierarchy in which common functionality is pushed up to the superclasses, and specific functionality falls downward towards the leaf classes, and maybe there are some templatized collection classes, along with a few interfaces. We can ply our specific domain against these constructs elegantly when the nouns of that domain are coordinate:
Of course, too much object-orientation, or “object orientation for object orientation’s sake”, can be a Very Bad Thing. If we asked Strunk and White they’d probably say:
5.6. Do not overwrite over-program
Rich, ornate prose code is hard to digest, generally unwholesome, and sometimes nauseating.
Ask yourself, when you’re trying to copy some text from location A to location B, whether it’s better to allocate a chain of distributed COM objects, consult the Registry, set up an eventing hierarchy and spawn a couple worker threads, or just use a plain vanilla string copy.
Another good one has to do with commenting code:
5.11. Do not explain too much.
It is seldom advisable to tell all. Be sparing, for instance, in the use of adverbs code comments…Let the conversation code itself disclose the speaker’s manner or condition coder’s intention.
Although each programmer has his own commenting philosophy, experience shows that the amount of code comments usually varies inversely with the programmer’s experience level; not because more experienced programmers are more lazy, but because their code is clearer in and of itself. Good code is self-documenting.
Last but not least, one of my favorite elements of style, and what to me is the fundamental rule of surviving a multiple-person development effort:
5.1 Place yourself in the background.
Write Program in a way that draws the reader’s attention to the sense and substance of the writing code, rather than to the mood and temper of the author programmer. If the writing code is solid and good, the mood and temper of the writer programmer will eventually be revealed, and not at the expense of the work.
There’s little to no room for ego in team-oriented production code. Pride of craftsmanship, yes. Petulant emotional investment, no. Subtract yourself from your code and watch your code improve. I may or may not be a talented programmer; you may or may not be; but if we’re capable of using every available resource, including the minds of those around us, and leveraging rather than resenting criticism levelled against “our” code, everything improves across the board.
Anyway, the next time you have a few spare minutes, grab that old copy of Strunk and White’s Elements of Style, and start applying some of your lifelong knowledge of the written word to programmable code. They’re two very different things, but beneath the differences, at the level of conceptualization, and in the serial process of actually cranking out individual lines of code, very much the same.