Re: File Extensions Problem
Re: File Extensions Problem
- Subject: Re: File Extensions Problem
- From: "R.L. Grigg" <email@hidden>
- Date: Wed, 27 Aug 2008 15:59:12 -0700
On Aug 27, 2008, at 12:19 PM, Ken Thomases wrote:
On Aug 27, 2008, at 1:50 PM, R.L. Grigg wrote:
This is interesting. Correct me if I'm wrong but as a newb what I'm
getting from all this is if I design my code around implementation
specifics of frameworks or even the language I'm using, that
equates to a unrobust design, cuz if the underlying implementation
changes, I'm screwed, whereas simpler, more bread-and-butter
"textbook" designs are much more likely to weather any underlying
implementation changes, sort of like keeping your design at a high
level and not dirtying it with low-level implementation specifics.
Is that a reasonable conclusion to draw?
The framework provides a contract as part of its public interface.
The contract specifies what responsibilities you have and what
responsibilities the framework has. Turning that around, the
framework has the right to expect you to uphold your
responsibilities and you have the right to expect the framework to
uphold its responsibilities. Neither of you have the right to
expect more than what's in the contract.
In other words, you should pay no attention to the implementation
details, which are defined as those things which aren't specified in
the contract.
The framework designers try to keep their declared responsibilities
as unrestrictive on them as is reasonable, given that they want to
provide a useful framework. The freedom that this gives them allows
them to alter the implementation details, perhaps to improve
performance or enable new features, but also perhaps just to make
life easier for them, speeding development of the framework.
Hmm, I guess the wrinkle in this particular case is if the "contract"
doesnt specify something that the programmer assumes to be safe to do
(like enumerating backwards), how can you know how to implement your
end? I guess there are times when the underlying implementation
details can/must influence your highlevel design?
Thx,
Russ
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