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At Sun, 22 Dec 2002 22:27:45 -0500, Marc Feeley wrote: > > I find this line of reasoning so compelling that I now advocate the > > elimination of `make-mutable-parameter'. > > You mean: parameters should be mutable according to the specified > semantics and "make-parameter" should create mutable parameter > objects, consequently "make-mutable-parameter" can be removed. No, I meant simply that `make-mutable-parameter' should be removed, with `make-parameter' left alone. So there would be no mutable parameters, because programmers can easily get them through mutable objects that are stored as parameter values. > > FWIW, I found your arguments in favor of `make-mutable-parameter' > > uncompelling: no particular use for it, but seems on the surface to be > > easier to implement, etc. These sort of arguments seem suspiciously > > like the ones that support dynamic scope over lexical scope. > > No the "efficiency of implementation" (of thread creation and > continuation transfer) is only a secondary reason. The primary reason > is that the semantics of parameter objects is closer to lexical > variables (the only difference is dynamic vs. lexical scope). This > makes them easier to understand. These are still unsatisfyingly abstract answers to me. I really want to see how one choice or the other makes programming easier, and I guess I'll have to keep looking for examples. Meanwhile, if mutable parameters must stay, I yield. Matthew