On Mon, Oct 24, 2016 at 8:34 AM, Marc Nieper-Wißkirchen <xxxxxx@nieper-wisskirchen.de> wrote:

This (the parent accessor can access the payload of a subtype) is certainly what is needed for using this SRFI in the real world. For example, it would be impossible to implement a record-type system à la SRFI 131 and 136 on top of SRFI 137 if it didn't provide this.

On reflection, I think it has to do both: a base-type accessor should be able to access the payload of an object of a derived type, and a derived-type accessor should be able to access the payload of an object of the base type. No?

John Cowan http://vrici.lojban.org/~cowan xxxxxx@ccil.org

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