(Responded to Joey offlist, but for others interested, here's a more detailed reply)
The "(#%expression (let-values () (let-values (((ws1) (#%expression ..." wrapper is a bunch of internal Racket stuff. For simple #lang's, I've been able to just ignore it, although I'm sure it's got some important binding information in general that someone else can comment on. In #lang Cur, I've got a similar process to Joey's language: fully expand and execute, then reflect back to the surface syntax. To deal with this `let-values` wrapping, I use the following syntax-class, `in-let-values`, to throw out the `let-values` wrappers and extract the body of the expression that I care about. https://github.com/wilbowma/cur/blob/b9a278c8105da2c7a848ff7886151858c84af62a/cur-lib/cur/curnel/racket-impl/stxutils.rkt#L81 I can then reflect the fully expanded syntax back into surface syntax (syntax->datum can suffice for simple Redex languages). For example, the Cur elaboration function is below. It calls `local-expand`, uses `in-let-values` throw out the let-values wrappers, and returned the body expression: https://github.com/wilbowma/cur/blob/246c8e06e245e6e09bbc471c84d69a9654ac2b0e/cur-lib/cur/curnel/racket-impl/type-check.rkt#L88 -- William J. Bowman On Thu, Jan 17, 2019 at 11:50:41AM -0800, Joey Eremondi wrote: > As part of my ongoing attempt to turn my Redex model into a #lang, I'm > wondering, is there a way to fully expand and evaluate a syntax object at > compile-time? I'm trying to get compile-time typechecking working. > > Here's what I have: > > * My Redex model uses names like TermLam, TermApp etc. > * I've defined lambda and #%app so that the user can write normal programs > that are translated into Redex terms. > * I've done (require (for/syntax redex/reduction-semantics > "my-redex-model.rkt")), so that I have access to my Redex model at compile > time > > When the user writes a term (using lambda and #%app macros), I need to take > the syntax object > > I'd tried using local-expand and syntax->datum, but I think it's expanding > too far, i.e. it's giving "(#%expression (let-values () (let-values (((ws1) > (#%expression ..." redex doesn't know how to interpret as a term. > > Is there a way to do this? Or am I trying to push redex farther than > intended? > > Thanks! > > -- > You received this message because you are subscribed to the Google Groups > "Racket Users" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > For more options, visit https://groups.google.com/d/optout. -- You received this message because you are subscribed to the Google Groups "Racket Users" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. For more options, visit https://groups.google.com/d/optout.
