[R6RS] "Sealed" record types

Michael Sperber sperber
Wed Jun 22 08:42:06 EDT 2005

Marc Feeley <feeley at iro.umontreal.ca> writes:

> But a non extensible default makes the code more secure, in the sense
> that the designer of a module has to explicitly say when it is OK to
> subtype a record type that he defined.  Moreover, for locally used
> records, which I think will be the typical case, there is no need for
> the record type to be extended.  As an added bonus the compiler can
> generate more efficient code.

Could you elaborate on your notion of security?  (I.e., why should it
not be OK to subtype a record type?)  Also, I'm curious on the
efficiency issue.

(I have no opinion in this---I have no experience with using or
implementing record extensions, so I'd appreciate a more in-depth

Cheers =8-} Mike
Friede, V?lkerverst?ndigung und ?berhaupt blabla

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