Re: why are there [v e c t o r s] in Lisp?

[Pascal J. Bourguignon]

Robert Thorpe <rt@robertthorpeconsulting.com> writes:

> Emanuel Berg <embe8573@student.uu.se> writes:
>> Now that I know it isn't so I don't think the
>> syntax is bad. Actually, I'm curious about CL and
>> using the industrial Lisps to do "real" programs,
>> where types, data structures, memory usage, come to
>> play once again.
>
> There's one thing that Pascal didn't mention directly....  In some cases
> having literal syntax in Lisp is more important than in other
> languages.  In Lisp we have the function "read" which can read in
> anything that has a read syntax.  Let's say you have a program that has
> an data file format.  That file can be stored using "print" and
> read-back using "read".  For example, configuration could be stored as a
> list.  That list could contain other lists, strings and vectors.  Read
> and print eliminate the need to write a parser.  As a side-effect they
> may make the file human readable.  That makes having a vector or array
> syntax more useful.  Let's say the program is a CAD package and it's
> storing a 3D model.  That would use a lot of arrays.  If Lisp had no
> literal array syntax then lists would have to be used, then converted to
> arrays later.  That could be very inefficient for large models.

Indeed, and this is why there are reader macros, print-object, (and also
make-load-form and make-load-form-saving-slots) in CL: the language
doesn't provide a reader syntax for all its data types because there
aren't enough characters in the standard character set ;-) but it
provides the user to define its own reader syntaxes, for predefined lisp
classes and for user defined lisp classes.

-- 
__Pascal Bourguignon__                 http://www.informatimago.com/
“The factory of the future will have only two employees, a man and a
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