[r6rs-discuss] Tweak to the description of eqv? on constants

From: Alan Watson <alan>
Date: Wed, 27 Jun 2007 17:41:10 -0500

The description of eqv? in section 11.5 says:

"Since the effect of trying to modify constant objects (those returned
by literal expressions) is unspecified, implementations are permitted,
though not required, to share structure between constants where
appropriate."

However, section 5.10 says:

"An attempt to store a new value into a location referred to by an
immutable object should raise an exception with condition type &assertion."

At first glance, then, section 5.10 does indeed specify the effect of
trying to modify constant objects. Now, one could argue against this
given the presence of "should". However, in the context of 11.5, the
reason that implementations are permitted to share structure is
irrelevant. Therefore, it might be best simply to remove the text "Since
the effect of trying to modify constant objects (those returned by
literal expressions) is unspecified" and leave:

"Implementations are permitted, though not required, to share structure
between constants where appropriate".

Regards,

Alan
Received on Wed Jun 27 2007 - 18:41:10 UTC