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Re: [Scheme-reports] [scheme-reports-wg1] Erratum for letrec* definition
Alex Shinn scripsit:
> I'm not sure we need bother clarifying this. Interleaving
> assignment is both the most natural and only realistic
> interpretation of the existing text. You have to stretch
> it quite a lot to think that it allows the <init>s to be
> evaluated outside the order of the assignments.
Well, someone on #scheme was complaining about it being unclear,
and when I looked at it, I realized that I had never really
understood letrec* before. He was under the impression that
letrec* is to letrec as let* is to let; that is, that letrec*
expands to nested letrecs. Anyway, Riastradh set both of us
straight, and clarified that although some Schemes implement
letrec as letrec*, this is definitely a bug. See the page
LetrecStar for which Schemes do what now.
So since it had confused at least one user, and I didn't correctly
understand it when I looked at it, I thought it would be good
to add a clarification.
John Cowan http://ccil.org/~cowan cowan@x
Lope de Vega: "It wonders me I can speak at all. Some caitiff rogue
did rudely yerk me on the knob, wherefrom my wits yet wander."
An Englishman: "Ay, belike a filchman to the nab'll leave you
crank for a spell." --Harry Turtledove, Ruled Britannia
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