Re: Objective-C and it's future

FROM : Thomas Davie
DATE : Sat Jul 08 03:40:39 2006

On 8 Jul 2006, at 02:35, Jon Hendry wrote:

> ".  So
> what's against having this descriptive power in the language when
> it's very useful for checking the correctness of the program. "
>
> But how often do you run into problems because you didn't have this 
> kind of checking?
>
> I don't think it ever happened to me in about 8 years of 
> professional Objective-C work.


Very often.  90% of the time I remove something from a container 
class I get the compiler warning me that it might not respond to the 
method I'm asking it to respond to, and have to make a cast, that I 
know is type safe, but the compiler does not.  I would much rather 
have the compiler do this inference for me, because firstly, it stops 
me from making mistakes, and secondly it saves me a lot of code 
making casts that do nothing.

Of note, when I'm writing Objective-C I spend a lot of my time 
tracking down annoying bugs, usually relating to memory management 
and usually the problem is that I've released something that wasn't 
what I expected it to be.  This is exactly the kind of error that a 
stronger type system would catch.  I've yet to spend any time 
tracking down runtime bugs that were not a "logical flaw" (i.e. me 
misinterpreting my model for how a program should run) when writing a 
Haskell (strongly typed functional language) program.

Bob