Subject: bug#11198: problems reading data with a "read-hash-extend" registered reader

From: Mark H Weaver <[email-masked]>
Date: Wed, 11 Apr 2012 15:33:32 -0400

[email-masked] (Ludovic Courtès) writes:
> Klaus Stehle <[email-masked]> skribis:
>
>> (read-hash-extend #\R read-R)
>
> Unlike previous versions, Guile 2.0 has distinct compilation and
> run-time phases.  Here you probably want the reader extension to become
> effective at compile-time (when compiling), and at evaluation-time (when
> interpreting the code):
>
>   (eval-when (compile eval)
>     (read-hash-extend #\R read-R))

I don't think this will be sufficient by itself, because 'read-R' will
not yet be bound at compile time.  You also need to define 'read-R'
within the 'eval-when', and everything else that's needed to run
'read-R'.

Alternatively, you could refrain from using the #\R syntax within the
same file where it is defined.

    Mark