The #%plain-app identifier is just a renamed version of #%app from '#%kernel, so it’s actually named #%app when initially defined. The racket/base version of #%app exists to handle keyword arguments, so racket/base exports the underlying version of #%app as #%plain-app. Of course, fully expanded programs use the version from '#%kernel, not racket/base, so the introduced #%app is not free-identifier=? to the one from racket/base.
I’m not sure that there is a good solution to the unintuitive printing behavior, given that this is a potential problem with any two identifiers with the same symbolic name but different bindings. In DrRacket, at least, you can expand the syntax object printed out and click on #%app to see that its binding is the one from '#%kernel. If you do the same with #%app from racket/base, you’ll see that it comes from racket/private/kw instead. > On Sep 28, 2016, at 16:05, 'William J. Bowman' via Racket Users > <[email protected]> wrote: > > Consider the following program: > > #lang racket > (require (for-syntax syntax/parse)) > > (define (Type x) x) > > (begin-for-syntax > (define x (local-expand #`(Type 1) 'expression null)) > > (displayln x) > > (displayln > (syntax-parse x > #:literals (Type #%app #%plain-app) > [(#%app Type i) > 1] > [(#%plain-app Type i) > 2]))) > > Naturally, I expect it to print: > #<syntax:/tmp/test.rkt:7:28 (#%app Type (quote 1))> > 1 > > But it doesn't: > #<syntax:/tmp/test.rkt:7:28 (#%app Type (quote 1))> > 2 > > -- > William J. Bowman > Northeastern University > College of Computer and Information Science -- 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.
