[racket] TLS "atom?" definition for Scheme does not work in DrRacket

From: Rufus (rlaggren at mail.com)
Date: Thu Mar 5 00:21:12 EST 2015


Yes, that is what happens. (with BSL) But if I remove the erroneous
(define and...) then it again flags pair? as "function not defined". I
think maybe it only prints one error msg, the last one found.

Sorry for the delay. I am rebuilding the laundry room here at my
sister's house during the day and now I'm trying to read up on the
evolution of program languages - I find that getting a handle on how/why
people did things helps me a lot to actually understand the concepts and
methods we have arrived at today. And I need all the help I can get. <g>
It's 30 yrs since I touched a line of code and I was never into the
theory stuff anyway.



On 03/04/2015 04:17 PM, Alexander D. Knauth wrote:
> On Mar 4, 2015, at 1:18 PM, Rufus <rlaggren at mail.com> wrote:
>> If I then add Alexander's example define so the def file appears as follows:
>> ---------
>> (define rufus 0)
>> (define atom? (lambda (arg1)
>>                (and (not (pair? arg1))
>>                     (not (null? arg1)))))
>> -------------
>> and hit Run I get an error in the I-pane:
>> "pair?; this function is not defined”.
> When you include this:
> (define and ‘dummy)
> Do you get:
> define: expected a variable name, or a function name and its variables (in parentheses), but found a keyword
> instead of the `pair?` error?

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