In Racket 7, at least, the first error I get is: has-blanks: arity mismatch; the expected number of arguments does not match the given number expected: 0 given: 1
After fixing that, it looks like, in your `read-syntax`, the `with-handlers` form catching `has-blanks?` emits a `module` form without necessarily consuming the entire input port, which is incorrect behavior: I believe `read-syntax` will end up being called again, thus producing multiple `module` forms. If you really want to read the whole body at once, you might look at the `#:whole-body-readers?` option with ` syntax/module-reader <http://docs.racket-lang.org/syntax/reader-helpers.html?q=syntax%2Fmodule-reader#%28mod-path._syntax%2Fmodule-reader%29> `. Another potential problem is that you provide `read` from Racket. Generally, `read` should be consistent with `read-syntax`. You can write a function like: (define (koan-read in) (syntax->datum #f (koan-read-syntax #f in))) and export it as `read` via `rename-out`. I recommend also calling your `read-syntax` `koan-read-syntax` internally: shadowing `read` and `read-syntax` is a recipie for confusion later, especially as e.g. your `read-syntax` is implemented using Racket's `read`. More broadly, I am very suspicious of the decision to recognize "blanks" (i.e. `_____`) at the reader level. I think it will probably turn out better to `(define-syntax _____ ...)` in your language implementation and bind `_____` to a macro that raises an error. You might look at the "todo-list" package (http://docs.racket-lang.org/todo-list/index.html) for a particularly slick way to handle it. If there is a compelling reason to do it at the reader level, I would suggest using `raise-read-error <http://docs.racket-lang.org/syntax/reader-helpers.html#(def._((lib._syntax%2Freaderr..rkt)._raise-read-error))>` rather than emitting code to raise an exception at run-time. I'm similarly not sure about the decision to use `convert-compile-time-error` in your `#%module-begin`, but maybe you have a good reason to do it that way. Also, why not `(provide (all-from-out rackunit))` from your language? -Philip On Sun, Aug 26, 2018 at 5:42 PM Sage Gerard <zyrolast...@gmail.com> wrote: > Hello all, > > First crack at a module language and stuck on a "expected only a `module' > declaration; found an extra form" error. This is not a duplicate of this > question <https://stackoverflow.com/q/37952163/394397> since the error is > slightly different and the error reproduces in the REPL. > > Here's my WIP implementation: > https://gist.github.com/zyrolasting/716aa9b09dd9f2436374428068a68aed > > I'm not sure what I'm missing since my reader does provide a single module > declaration via the datums->module shown in the gist, and AFAIK I'm running > an implied module below. > > What was my mistake? Apologies if I just went blind on a simple error. > > #lang reader "racket-koans-lang.rkt" > (require rackunit) > > (struct _____) > (struct _____) > (let ([p _____]) > (check-pred racketeer? p) > (check-pred programmer? p) > (check-pred struct? p) > (check-pred procedure? set-programmer-salary!) > (check-equal? (programmer-confusion-level p) 10) > (check-equal? (racketeer-desire-for-racket-jobs p) 9001)) > > > > -- > 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 racket-users+unsubscr...@googlegroups.com. > 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 racket-users+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
