Re^9: Developing a module, how do you do it ?

I would like to use more testing

I do test. Just not with the Test::* tools.

It is my contention that when writing a module, you should write the application (or at least an application) that uses that module, concurrently with the development of the module itself. This improves the module design by ensuring that its interface works with the needs of the application. That it has the entry points the application needs, and no more. The application becomes the prototypical test-bed for the module.

Far too many modules are developed in isolation of their use case, designed on the basis of what-if and maybe and it-could-do, hence you end up with clumsy, fragile, bloated, and over-specified interface definitions

Once the module is written and working with the application, then is the time to go back and see if it can be generalised to some degree, without breaking the original use case. At that point I write a generic application -- a cut-down and simplified version of the original use case -- that self-checks its own results and serves as test case and regression test, and lives in the module file itself. It can then be annotated and also serves as user documentation for the module.

With the rise and rise of 'Social' network sites: 'Computers are making people easier to use everyday'

Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error.

"Science is about questioning the status quo. Questioning authority".

In the absence of evidence, opinion is indistinguishable from prejudice.

The start of some sanity?

Comment on Re^9: Developing a module, how do you do it ?

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Re^10: Developing a module, how do you do it ? by aaron_baugher (Curate) on Mar 03, 2012 at 20:58 UTC
I may have spoken out of turn, since I've only written a few modules. But I think one reason for that is the OO attitude you describe, where writing a module means a separate project done in isolation, hoping that someday maybe it just might be useful for something else, so you spend a lot of extra time trying to make it generically accessible. Since I generally just want a piece of code that does one thing, that kind of module writing never seemed to make much sense. It's interesting to hear someone describe writing a module for a specific use case. Aaron B. My Woefully Neglected Blog, where I occasionally mention Perl.	[reply]
Re^11: Developing a module, how do you do it ? by BrowserUk (Patriarch) on Mar 03, 2012 at 21:18 UTC
I think one reason for that is the OO attitude you describe, where writing a module means a separate project done in isolation, hoping that someday maybe it just might be useful for something else, so you spend a lot of extra time trying to make it generically accessible. Indeed. Though the problem is not confined to OO modules alone, but it certainly seems more prevalent in the OO way of working. Designing any interface -- software, user, or hardware -- in isolation of the way it will actually need to be used, makes for high impedance almost every time. And it is far easier to add to a minimal interface as (and when) new requirements become known, than it is to work around an over-specified interface that guessed wrong about what might be needed in the future. Once the latter is out there, respecify for actual new requirements, or removing the redundant, becomes impossible, because you don't know what bits someone, somewhere will have used, no matter how inappropriately. What-ifs and maybes -- trying to predict the future and guess what applications might need -- is the ongoing curse of the software industry. Add it when you know it is needed. Never before that. With the rise and rise of 'Social' network sites: 'Computers are making people easier to use everyday' Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error. "Science is about questioning the status quo. Questioning authority". In the absence of evidence, opinion is indistinguishable from prejudice. The start of some sanity?	[reply]