From: Phillip Gawlowski <pg@...>
Date: 2009-12-30T02:46:09+09:00
Subject: Re: Creating my own method for sorting an array

On 29.12.2009 18:32, Marnen Laibow-Koser wrote:
> Yup.  It's more fun to program with good tests.  You can go faster, and
> you can see things work right away.

Hahahaha. No.
Tests are a safety net (and a rather thin one), that a beginner doesn't 
need.

It's a good habit to get into, yes. After a beginner knows what this 
"programming" thing is, and thus can understand what tests are, and how 
to write a good test. A *test* is another level of abstraction that a 
beginner at programming doesn't need, and doesn't understand as yet.

And an improperly written test is worse than no test at all: It makes 
you believe that your code is correct when it isn't.

> Anyway, if he's really a new programmer, he shouldn't be writing sort
> algorithms.

Why not? It's the most basic algorithm there is, allow fancy-pants 
things like recursion to be explored with (comparative) ease.


> I didn't say a word about design patterns.  All I recommended was tests.
> These actually make it less confusing, since you can more clearly see
> what's going on.

Tests *are* a design pattern.

> And we'd all be better programmers if we thought about good practice as
> an integral part of the craft, not something bolted on later.

Every apprentice, in any craft, learns the basics of a craft first, and 
*then* moves on to the complex things.

Would you expect a carpenter to be able to plan a table before s/he is 
able to hold a drill properly?

>> Yeah, the way I tell if I have a working program is (generally) to run
>> it.
>
> The tests run it for you.  Have you ever actually tried this?  Sounds
> like not.

Tests don't run a program. They check if a part of a program, an atomic 
piece, is correct as defined by the test.

> For "hello world", yes.  For anything more complex, no.  And a sort
> implementation is certainly complex.

You don't need tests for something complex. Nor do you need them for 
something "simple". You need them for something that requires *correctness*.

> I did give him some guidance.  Now, since you brought it up...what
> guidance have *you* given him?

Good guidance: Not to listen to know-it-alls unable to grasp what's 
appropriate for a given situation and what isn't.

--
Phillip Gawlowski