On Fri, May 1, 2015 at 2:33 PM, Jonathan S. Shapiro <[email protected]> wrote: > On Fri, May 1, 2015 at 11:14 AM, Raoul Duke <[email protected]> wrote: >> >> > x is not rebound because it has gone out of scope. Most functional >> > languages nonetheless diagnose this as a rebinding. >> >> wow, i never knew/noticed that. >> >> seems kind of lame to me. > > > I'd characterize it as a discrepancy between the semantics and the > requirements of usability. From a semantic perspective, there actually *is* > a top-level let binding whether you use LET or DEF or some other keyword. > What's odd about this case is that when LET is used at top-level it has > different behavior than when it is used internal to a procedure (where a > second binding of x after the first binding goes out of scope usually is NOT > diagnosed. > > To put it another way: diagnosing the rebinding means that in a weird way a > let-bound binding places it's symbol in a special scope that is just > *outside* the scope of the let and just *inside* what we would normally > think of as the parent scope. We can certainly tell a story about that which > makes the behavior consistent, rational, and explained. It's just that this > story isn't the story we are actually telling about the behavior of LET. :-)
This sounds way too weird. Which languages do this? SML or OCaml? Can you give some code showing why it doesn't work the way PKE says? Pal's story is how I always understood it. _______________________________________________ bitc-dev mailing list [email protected] http://www.coyotos.org/mailman/listinfo/bitc-dev
