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Re: First cut at "curly-write" and "neoteric-write" with -shared and -cyclic versions

This page is part of the web mail archives of SRFI 110 from before July 7th, 2015. The new archives for SRFI 110 contain all messages, not just those from before July 7th, 2015.

Beni Cherniavsky-Paskin <cben@xxxxxxxxxxxx> wrote:

> I'm getting some errors [guile 2.0.7]:

Thanks for the report!  I don't have guile 2.0.7 (yet); so this is a new problem to me.


> -#0=(quote . #0#)
> +'x

Hmm.. This report means that when (all) the writers were asked to
write out "(quote x)", they output:
  #0=(quote . #0#)

Instead of the correct:

Clearly the writers are getting it *completely* wrong.
What's weird is that the code works on older versions of guile, and it's based on
fairly well-tested code.  I'm also surprised the more complicated cases worked (!).

My guess is that there's a semantics issue with the hash table implementation.
If the hash table thought that the outer list and the symbol x were "eq?"... or used the
wrong equality operator so they'd be considered equal... then the code would do this.

Guile supports several hash table systems; I used the SRFI-69 hash tables because
they are especially portable.  But I did have to use a special declaration to get srfi-69
hash tables in guile without lots of spurious warnings.
Perhaps that special declaration no longer works in guile 2.0.7.

Can you replace the current lines:
  (use-modules ((srfi srfi-69)
               #:select ((make-hash-table . srfi-69-make-hash-table)
                         (hash-table? . srfi-69-hash-table?)
                         hash-table-delete! )))

with just:
  (use-modules (srfi srfi-69))

and try again with guile 2.0.7?
The guile 2 manual says that this is the correct way to import srfi-69:

--- David A. Wheeler