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AlexKnauth / reprovide-lang

a simple racket language for reproviding modules
MIT License
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Use `syntax/lang` to abstract over language creation plumbing #1

Closed jackfirth closed 8 years ago

jackfirth commented 8 years ago

This PR uses a new library I made, syntax-lang, to simplify the implementation of the language. define-lang-syntax uses reader submodules and syntax/module-reader to create a new #lang from a given macro, similar to syntax/module-reader. Reader submodules let it keep all the code for reading and expanding in the same file. For details of how that works, see the submodules blog post. (I couldn't find anything in the docs about reader submodules, as far as I know they're only mentioned in that blog post.)

This is mostly a test of the library, let me know what you think.

AlexKnauth commented 8 years ago

I don't really like the idea of a define-lang-syntax form expanding to a submodule, but if syntax/lang (or a similar thing) could be a module language for the same purpose, that would be awesome. I'm thinking of something like this:

(module reader syntax/lang reprovide reprovide)

Instead of this:

(define-lang-syntax reprovide reprovide)

That way it's obvious that it's a reader submodule. Also I feel like syntax/lang should be reserved for something more general instead of something this specific. Would syntax/macro-lang be clearer? Since it takes the module body and treats it as the input to the reprovide macro?

(module reader syntax/macro-lang reprovide reprovide)
AlexKnauth commented 8 years ago

I just realized my suggestion wouldn't allow reprovide to be used as a module language. So would this work: reprovide/main.rkt

#lang s-exp syntax/macro-lang reprovide reprovide
(require reprovide/reprovide)
(provide #%datum ...)

As equivalent to:

#lang racket/base
(require reprovide/reprovide)
(provide #%datum ...)
(provide (rename-out [new-module-begin #%module-begin]))
(define-syntax-rule (new-module-begin module-body (... ...))
  (#%module-begin (reprovide module-body (... ...))))
(module reader syntax/module-reader reprovide)

Would that be a better solution?

AlexKnauth commented 8 years ago

I just did that with https://github.com/AlexKnauth/syntax-macro-lang

jackfirth commented 8 years ago

Yes, that's much better and one of the ideas I had for something to build on top of the syntax-lang package.