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

From: Rufus (rlaggren at mail.com)
Date: Tue Mar 3 18:34:53 EST 2015


My goodness. There seems to be some strangeness here.

1) When using "#lang racket" and running the defs file,
   - Atom? is defined regardless of whether the "AND clause
      get parens ie. "Atom?" entered on the interactive pane
      (then hit Enter) tells us it's a proc regardless the
      way it's defined.
   - (Atom? x) (where x is defined) throws an error if its
      definition used parens around the AND clause but works
      as expected w/out them.

2) When using BSL-lists:
   - Atom? can be defined on the interactive pane using parens
      around the AND clause the way it appears in TLS; it
      works as expected.
   - Atom? cannot be defined on the i-pane w/out the parens
      around the AND clause because it throws a syntax error.

3) As an aside: Under BSL-lists, I cannot get any code in the
    defs file to run. At least none of the definitions exist
    after I load the file and click "Run". So now it comes back
    to me exactly what led me to use the "#lang racket" spec:
    The code in the defs file was not getting executed when I
    used the BSL-lists, loaded the defs file and clicked Run.

GOT IT! The toggle for the atom? weirdness is the (define and '...)
included in the variable defs I made up from the TLS examples. Ie. a
reserved word problem. Doesn't know the exact mechanism but nottt a
problem. <g>

Still unclear on why BSL-lists apparently won't run a defs file. Another


On 03/03/2015 03:20 PM, Matthias Felleisen wrote:
> Use BSL with List Abbreviation. 

Posted on the users mailing list.