Actually most of what you are putting them down for is actually good advice. I likewise use few comments, use descriptive variable names, comment each function, etc. If you are relying on understanding comments rather than figuring out the code, you will have serious problems when the two disagree.
This is only true when you fall into the common trap of believing that comments are about explaining what you're doing in the code.
Comments shouldn't be doing that. The code should be easy enough to follow that it's pretty clear what it's doing.
Comments should be explaining WHY you're doing
what you're doing. That's the bit that's hardest for someone to reconstruct after the event:
"Yes, I can see that this loop is stepping through each item, building a hash of hashes of their info keyed by concatenating the title and the ID ... but WHY?"
Once you realise it's so they can easily sort by title at the end, but that keying the hash on title wasn't enough as not every product had a unique title, then this makes sense. A well written comment would have made this process a lot easier, however.
Comments are there mainly for the benefit of anyone who has to maintain your code later (including yourself!). They should explain all the bits where people will go "So, why exactly are they doing this like this?"
Tony
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I have posted enough code to this site, feel free to grab
some and criticize.
When I have examined my code in the past I find that my
average function is about 10 lines. At a guess about
1/3 of those functions are public for whatever package
they are in. Public functions get a comment. Function
names are descriptive. Most variables are private to a
function.
If I cannot find a descriptive name for a 10 line function
that gives you some idea why that function exists, that
indicates a problem in how I am breaking the problem up.
As with any personal style, it takes getting used to. And
no, I don't always do a particulalry good job of it.
But I don't think that modularizing less and commenting
more would be an improvement.
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Yes, you're a good coder and you write clean code. There's very little you'll release to production that I can't figure out mechanically, and vice versa.
There is, however, a great difference between understanding *what* you are doing and *why* you are doing it. This applies when working around bugs, when implementing business rules (which have, at best, a rather tenuous and dispassionate relationship with what we would call reality), and when doing things one way instead of another.
How else will other good coders distinguish between personal preference (using defined tests on variables instead of oring them in place with default values) and operations and assumptions necessary for your code to work.
I will only mention mere mortal programmers in passing.
Having recently come up to speed on a large and complex and evolving codebase with minimal documentation and no further hints as to its name and nature, I will repeat that understanding the mechanics of a program is rarely beyond the abilities of your average caffiene-stymied simian.
It is only discerning the will and the intent of the programmer that allows you to proceed without fear. That means coding by intent, expressing the design by way of metaphor (of which descriptive names play a part), and that means commenting your code with the assumptions you make and the reasons for any non-obvious decisions.
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tilly, while I agree in theory with what you are saying, I have a problem with this.
Let's say I have a program that reads an initialization file, opens a data file, does some processing, summarizing, error reporting, etc. A simple outline of the program might run like this (sorry for the formatting):
|--initialization--|--read .ini file
| |--set globals
| |--open files
|
main-|--process ledger--|--while not eof
| |
| | read next line |--addToProcessA
| | |
| | determine type--|--discard
| | |
| | write to file |--error reporting
|
|--termination-----|-- summarize results
| write summary to file
| close file
If that's the case, it's relatively simple to document and follow the process flow. But, even for a simple process like this, here's what I usually find in production programs:
read .ini file
set globals
open files
while not eof
read next line
determine type
addToProcessA
-or-
discard
-or-
error reporting
end while
write results
summarize
write summary to file
close file
It's a fairly linear run-through from top to bottom. There is little if any attempt to modularize the code. When that gets significantly larger, documentation becomes critical. I'm not disagreeing with how one should write the programs (small functions are the way to go), but many, if not most of the programmers that I have met simply don't appreciate this.
As a side note, I find that even those who do appreciate this will often do the straight run-through rather than the modularization. I sometimes have that in my code (usually a sign that I've been given rotten specs).
As a second side note, I just hacked together the example. There's no serious attempt to make the names more sensible or to really break it down properly. I'll call it pseudo-Warnier-Orr :-)
Cheers,
Ovid
Join the Perlmonks Setiathome Group or just click on the the link and check out our stats. | [reply]
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I agree that all those things are good practise, but I feel there is more to it. A code map along the lines of "Well, we're going to have a main routine which fires up different function libraries depending on the cgi params, each case will be handled like this:....". You know, a general layout including future directions for the coders to go in. You need something like that when you have three people working on the same code.
And yes, their main problem was that they didn't understand OO in the slightest, and were using global variables rather than presenting methods/data in a useful, consistant way. I suspect if they had sat down and written out what they were trying to do, they would have started to spot ways to improve their code. Perhaps that's program design versus programming. The code had apparently grown out of a 'quick hack' that someone put together one day, so it was kinda lumpy and directionless.
In my mind good documentation is an art as much as coding or writing is. It isn't necessarily explaining what every line does. Having said that I'm off to edit my code snippit before somebody reads all my posts and plays spot the hippocritic bastard :) ____________________
Jeremy
I didn't believe in evil until I dated it. | [reply] |
IMHO you are describing the difference between programming
and coding...
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