Hello everyone, There was some discussion in the "Identities in Peval" thread about using a CPS-like intermediate representation in Guile.
I think that our goal with our intermediate representation should be to make things convenient for us - we shouldn't try to match any particular model unless it helps us, and we should be happy customizing it for ourselves. From this point of view, I see two orthogonal issues with Tree-IL. First, some of the tree-il forms have their own control-flow properties, which doesn't work well with a uniform representation of control flow. They also complicate the big match statements in peval. Why not make dynlet, dynwind, dynref, dynset, prompt, and abort into primitives? Code that cares can still match them, and code that doesn't care can ignore them. Second, the idea of annotating tree-il forms with their continuations. I think that could actually be done fairly simply, if we remove the contraint that they have to be useful :-). I'm imagining that at first continuations would be like source information, in that they are passed everywhere but the compiler doesn't use them. You could even keep a separate hash table of continuations if you really wanted to, but that seems like more effort to me. I think it would be fine to have a hybrid compiler for bit that did some analyses using the continuation information and some using the tree-il structure. That might help with the issue of named primitives, too - we could still generate code from the tree structure. What do you think? Noah
