Hi Everyone,
I’ve been following the discussion on strong encapsulation with
interest… It’s a really interesting topic.
Reading through the posts and some of the Ruby books and
documentation, I’ve come across the idea that Ruby’s lack of strong
typing is less important because there is some support for a unit
testing framework.
My attention was grabbed by Jeff’s response in the original thread,
so instead of hijacking it, I thought it might be interesting to
start a new discussion. I thought I’d kick things off with these
points, sort of in order of priority:
Software engineering
o In our experience, putting well defined layers into the code has
always helped clarify the system
o You can never tell what your users are going to do with your
code! More protection is usually better 
o Clarity and reliability are almost always more important than speed
Testing in the real world
o Very often, only superficial testing is done, and this only
catches the trivial stuff
o It’s easy to catch the easy errors. To catch the hard ones takes
a lot of work
o The late-breaking bugs are the ones that hurt - especially if
it’s a silly typo that could have been caught statically
Unit testing
o Often the problems crop up in integration rather than within a
particular unit - having stricter checking on interfaces would really
help
o It’s hard to push a unit into all corners of it’s functionality
without reasonably fully fledged supporting functionality
o If the testbench suffers from the same limitations as the
language it’s testing, how do you know where the error’s being
generated?
Testing methodology
o There’s a difference between syntax checking and verification of
functional correctness
o Rigorous testing of software is often extremely hard to do, if
not impossible - esp GUIs and large web apps
o Strict type checking can really help with the readability and
maintainability of code
Just so you know where I’m coming from, I work verifying functional
correctness of CPUs and designing the supporting tool flows. I have a
strong disposition towards strong encapsulation, typing and testing,
and even then I never do enough testing!
What do you all think?
Cheers,
Nick
–
Nick P.
[email protected]
