With scheme48 0.57, I'm trying to pass an inexact value into C code.
However, whenever I call s48_extract_double on an s48_value (like 1.5 or
(exact->inexact 1)), I get a message like:
(call-external-value "scmDoubleDouble" 1.5)
After further investigation, I found that the STOB_TYPE for the
s48_value being passed along was S48_STOBTYPE_EXTENDED_NUMBER (11),
but the code in the double conversion routine will only take
Furthermore, on first glance it seems like there is no way to generate
S48_STOBTYPE_DOUBLE's other than calling something like
"inexact = s48_enter_double();" from C code, but then once I pass
'inexact' back to the Scheme interpreter, none of the standard
procedures (like 'display') can handle it.
Has anyone else run into this problem? I'm going to go ahead and hack
up the source in the meantime to try to work around this (I'll probably
attempt to figure out how to convert an extended-number into a double
from within the code for s48_extract_double) but I'd like to know if
there's better way someone else has already come up with.
p.s. do people find this list a better place to pose scheme48 specific
questions (as opposed to comp.lang.scheme)? Or would it be better for
me to be asking there instead? I know this is really supposed to be a
newsgroup about scsh (and I am a happy user of scsh!) but I figured
since scsh is a layer on top of scheme48, some people were probably
well-versed with both systems....