Re: New shared substring implementation

[Christian Lynbech <chl@tbit.dk>]

>>>>> "Mikael" == Mikael Djurfeldt <mdj@nada.kth.se> writes:

Mikael> Now, is it good for Guile?  I don't think so.  (Even though I'm a
Mikael> sinner in this respect) I think it's important to keep Guile's user
Mikael> interface simple.  I don't think the gain of enabling the user
Mikael> to manipulate with sharedness of strings balances the cost of the
Mikael> increased conceptual complexity added to the interface.

I can see that the usefullness of truly shared strings may be limited,
and I was probably protesting mostly out of habbit, since I tend to
get mixed emotions about kicking saomething out that actually works
and fills a purpose in my programs.

However, I do not think that the complexity argument is good. Guile
(and scheme for that matter) is filled with complex stuff (think
call/cc). Having an extra kind of strings is no different than many of
the other extensions that guile puts in the hands of users. If you
want the simplcity of standard R4RS scheme, by all means keep to that.

Mikael> There are probably extremely few cases when you can write a good
Mikael> program using shared substrings.  My guess is that in most candidate
Mikael> cases it's a question of "tricky" programming which rather is a kind
Mikael> of misuse of data structures, exploiting the properties of shared
Mikael> substrings to achieve something which isn't "stringy" at all.

As to "stringyness", I do not see why a string cannot be shared
(across element updates) when other sequences such as vectors can, but
perhaps this is just my TradLisp perspective getting in my way again :-)



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Christian Lynbech          | Telebit Communications A/S                       
Fax:   +45 8628 8186       | Fabrikvej 11, DK-8260 Viby J
Phone: +45 8628 8177 + 28  | email: chl@tbit.dk --- URL: http://www.telebit.dk
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Hit the philistines three times over the head with the Elisp reference manual.
                                        - petonic@hal.com (Michael A. Petonic)