On 25.11.2008, at 15:06, Konrad Hinsen wrote: > I just saw a reference to symbol-macrolet with a description. My > function replace-syms is indeed very similar, the difference being > that it takes a map for defining the substitutions to be done, > instead of a let-like sequence. The difference is not just in syntax > though, as expressions in symbol-macrolet can refer to earlier > "bindings" (they aren't really bindings) whereas my replace-syms > doesn't check for substitutions to be made inside other > substitutions. But it would be fairly easy to implement symbol- > macrolet on top of my replace-syms.
After having read more on macrolet and symbol-macrolet, I no longer agree with my earlier self ;-) symbol-macrolet does not do a simple substitution, it creates a binding-like environment from which replacements are done repeatedly as other macros are expanded. I haven't yet found a complete description of how macros and symbol-macrolet work together. A macro can expand into code that contains a symbol defined in symbol- macrolet, and the expansion of such a symbol can produce code containing macros. I'd expect everything to be expanded repeatedly until the form no longer changes, but I haven't see this being stated explicitly anywhere. In any case, implementing macrolet and symbol-macrolet is probably not a trivial project. I see basically two approaches: 1) Full repeated expansion of the form, which is then handed to the compiler. 2) Implementation as an extension to the compiler's macro handling scheme. When I started working on my monad implementation, I was in fact looking for something much like macrolet, and if I had pursued that approach I would have wanted symbol-macrolet just a bit later. Both would be nice to have. Konrad. --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Clojure" group. To post to this group, send email to clojure@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/clojure?hl=en -~----------~----~----~----~------~----~------~--~---
