[plt-scheme] eval define

From: Noel Welsh (noelwelsh at gmail.com)
Date: Fri May 22 01:26:19 EDT 2009

On Thu, May 21, 2009 at 8:59 PM, Jon Stenerson <jonstenerson at comcast.net> wrote:
> So my question is: in r6rs how do you arrange for runtime decisions about
> definitions (on the basis of the content of a data file for instance)?

I don't know about R6RS, as I don't use it. However, if this is really
your use case, it doesn't make sense. Let's say you're going to define
x in some cases and y in others. How are you then going to write code
that conditionally uses one of these definitions? You can't. I.e. you
can't write

(if-defined x
  (do-something x)
  (do-something y))

Doing this:

  (define x (eval some-expr))

is a better way to go.


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