John Cowan <cowan@x> writes: > I don't see how that can be. Multiple values first appeared (AFAIK) in > Zetalisp, which did not have first-class continuations. Quoth the 3rd > (1981) edition of the Chine Nual: > > When a function needs to return more than one result to its caller, > multiple values are a cleaner way of doing this than returning > a list of the values or setq-ing special variables to the extra > values. > > I don't know when multiple values were first provided in a Scheme > implementation, but they do not appear in R4RS, and the Ashley & Dybvig > paper speaks in 1994 of "the new Scheme multiple values interface". > If they existed at the time of RRRS (1985) but were not standardized, > they would still postdate the Zetalisp implementation by some years. Well, this is clearly not correct. Multiple value return (in the context Eli mentions, as a natural context of first-class continuations) is discussed explicitly in GLS's "LAMBDA: The Ultimate Declarative", From November of 1976, where it warrants its own appendix (and is already referred to as the `old' CPS implementation by the time of GLS's thesis a year later). -- Jim Wise jwise@x
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