[plt-scheme] Tip: installing PLAI Scheme in DrScheme 4.2

A quick question to Shriram: I installed PLT 4.2.1 a few days ago and ran
(require (planet plai/plai:1:3)).

Then upon this code in the PLAI book, PLT fired an error saying "expand:
unbound identifier in module in: num"

(define (parse sexp)
  (cond
    [(number? sexp) (num sexp)]
    [(list? sexp)
     (case (first sexp)
       [(+) (add (parse (second sexp))
                 (parse (third sexp)))]
       [(-) (sub (parse (second sexp))
                 (parse (third sexp)))])]))

Is the reader supposed to write num (and add/sub) to make everything work
then?

Thanks,
Pan, Xingzhi


2009/6/15 Neil Van Dyke <neil at neilvandyke.org>

> Shriram Krishnamurthi wrote at 06/14/2009 10:54 PM:
>
>>
>> Or perhaps the system should behave better?  I think you have it backward.
>>  128 Mb seems like perfectly enough memory to *install a package* (and build
>> its docs).  (I am actually surprised that this has *memory* problems, as
>> opposed to being entirely i/o bound.)
>>
>>
> It might just be that documentation-building could stand some more
> optimization:
>
> http://list.cs.brown.edu/pipermail/plt-dev/2009-May/000933.html
>
> Or perhaps some PLaneT code is doing something like sucking a file into
> memory.  (Last year, I reimplemented some of the HTTP functionality to,
> among other things, get rid of at least one place where big-file-sucking
> happens, but I don't think that particular functionality is involved in
> PLaneT installs.)
>
> --
> http://www.neilvandyke.org/
>
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