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Michael Champion wrote:
> I'd take some issue with "strong, static typing is brittle and
> inflexible; and to see that systems that solve real problems need to
> be a lot more open and flexible". Systems that solve SOME real
> problems need to be more flexible, but flexibility creates new
> problems of its own, especially in the realms of reliability and
> security at a reasonable cost. The fewer the options, the easier the
> decisions that developers must make can be and thus the more reliable
> the code tends to be and the more rigorous the testing / auditing can
> be for a given cost. You probably don't want anyone at the bank being
> creative and flexible with how they format the information that goes
> into complex financial transactions. But by the same token, you
> probably DO want them to support lots of flexibility in how you as a
> consumer interact with them. Interesting tradeoffs...
>
This is a scenario Walter Perry's worked on. I think the key insight is
that there's a phase shift between the internal systems within the bank
and the customer and client facing systems. Strong rigid typing works
inside the bank. It fails once the bank starts speaking to others
though. Inside our companies and organizations, we tend to have single
data models. However every organization has different data models, so
types can't be as rigid.
Of course, for very large or diverse organizations (governments, very
large corporations, member consortia) the phase shift may occur at
inter-departmental boundaries rather than at the organization's edge.
When the widest networks only covered a department, if that, this wasn't
obvious. Inter-company communication took place mostly via paper; and
data models were not exchanged. However, as business moves onto the
Internet, the old assumptions are breaking down. Ships that sail well in
local waters are not normally suited for circumnavigating the globe.
--
Elliotte Rusty Harold elharo@metalab.unc.edu
XML in a Nutshell 3rd Edition Just Published!
http://www.cafeconleche.org/books/xian3/
http://www.amazon.com/exec/obidos/ISBN=0596007647/cafeaulaitA/ref=nosim
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