[racket] Matthew's "doc-define.rkt"

At Thu, 8 May 2014 20:40:35 +0200, Laurent wrote:
> At the end of Matthew's (awesome and quite informative) "metaprogramming"
> video [1] he uses a doc-string+contract `define`.
> 
> Is the "doc-define.rkt" file available somewhere? Google only led me to the
> corresponding paper [2] but I could not find the file in the archives.

The complete implementation is below. As you can see, it's just enough
to make the talk's example run.

> Also, I'm wondering why he chose not to show the usual in-source
> documentation of Racket and instead went for something that is not built in
> Racket as of today.

The current in-source documentation tool is an experiment to figure out
what we want and how it can work. I think the "doc-define.rkt" sketch
better illustrates what we've figured out that we want --- not all in
place, yet, but within reach --- and so it makes more sense in a talk.

----------------------------------------

#lang racket/base
(require (for-syntax racket/base)
         scribble/srcdoc)

(provide (rename-out [new-define define])
         (all-from-out scribble/srcdoc))

(define-syntax (new-define stx)
  (syntax-case stx ()
    [(_ (id arg ...)
        #:contract ctc
        #:doc doc
        body ...)
     #'(begin
         (provide
          (proc-doc/names id
                          ctc
                          (arg ...)
                          doc))
         (define (id arg ...) body ...))]))