[racket] Unexpected error extracting value from request bindings.

From: Hendrik Boom (hendrik at topoi.pooq.com)
Date: Mon Aug 1 12:20:06 EDT 2011

On Mon, Aug 01, 2011 at 01:08:27AM -0400, Neil Van Dyke wrote:
> Esoterica #2: You'll see functions like "gensym" and "gentemp" in
> some old Lisp dialects, and they will be used mostly to get around
> problems of non-hygienic macros in that particular dialect.  I don't
> recall seeing them used in real Racket or Scheme code, however,
> probably because those languages have hygienic macros.

I've used them extensively in programs doing theorem proving on formulas 
involving quantifiers.  This had noting to do with macros, hygienic or 

> Estoterica #3: In some Lisp dialects (not Racket), interned symbols
> are not garbage-collected, so, if you tried to generate unique
> symbols infinite numbers of times in a run of a program,
> *eventually* they might want to take up more space than can be
> represented by your computer and then by the universe.

Getting them garbage-collected was essential.

One thing that's useful is to have the print routine assign names to the 
symbols.  Symbols that are never printed never need to have names.  The 
few that actually are printed can then have shorter names.

-- hendrik

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