[plt-scheme] Re: to define, or to let

From: Bradd W. Szonye (bradd+plt at szonye.com)
Date: Mon Apr 19 22:24:56 EDT 2004

Bill Richter wrote:
> But suppose that C/C++ from the beginning had mandated a non-ambiguous
> eval order (say l->r).  Then these order of eval bugs aren't bugs
> necessarily ....

Sure they are. In the engineering contexts I'm used to, an
implementation that doesn't match the design or that's fragile is almost
as buggy as one that's more obviously incorrect. And if your design
doesn't consider things like "where sequencing matters," then your
design is incomplete at best.

> I bet it's a good thing.  I was dumb-founded when earlier in the
> thread I realized, "Hey, R5RS Scheme wasn't an algorithm, it was
> ambiguous, and so was C.  Dang, why didn't I realize that?"  Seems
> like there are places to go from there, and new places even.

Language specs generally aren't supposed to be algorithms. And language
implementations that encourage the "moral hazard" (thanks, Anton!) of
ignoring the "where sequencing matters" issue are irresponsible on some
level, IMO.
Bradd W. Szonye

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