[plt-scheme] verifying whether a symbol is defined at compile time?

From: Yin-So Chen (yinso.chen at gmail.com)
Date: Sun Apr 22 04:57:26 EDT 2007

Hi all -

Is there a way to verify whether a symbol is defined (or imported) at
compile time?  I am trying to write a conditional define macro (e.g.
define-once) that will evaluate to define if the variable is not previously
defined, but struggling to figure out how to determine whether a symbol's
existence.  (namespace-defined? v) doesn't appear to work for compile-time.


...continuous learning...
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