improve defproc* to support multiple bindings documented together (instead of just multiple forms of the same binding)

svn: r7285

original commit: 5154426cf61509fa76f6c9a88184dab5f860cf36

collects/scribble/manual.ss

@@ -858,7 +858,14 @@
              prototypes
              arg-contractss
              result-contracts
-             (cons #t (map (lambda (x) #f) (cdr prototypes))))))
+             (let loop ([ps prototypes][accum null])
+               (cond
+                [(null? ps) null]
+                [(ormap (lambda (a) (eq? (caar ps) a)) accum)
+                 (cons #f (loop (cdr ps) accum))]
+                [else
+                 (cons #t (loop (cdr ps)
+                                (cons (caar ps) accum)))])))))
           (content-thunk))))))
 
   (define (make-target-element* inner-make-target-element stx-id content wrappers)

collects/scribblings/scribble/manual.scrbl

@@ -225,7 +225,13 @@ source layout.}
                    pre-flow ...)]{
 
 Like @scheme[defproc], but for multiple cases with the same
-@scheme[id].  }
+@scheme[id]. 
+
+When an @scheme[id] has multiple calling cases, they must be defined
+with a single @scheme[defproc*], so that a single definition point
+exists for the @scheme[id]. However, multiple distinct @scheme[id]s
+can also be defined by a single @scheme[defproc*], for the case that
+it's best to document a related group of procedures at once.}
 
 
 @defform/subs[(defform maybe-literals (id . datum) pre-flow ...)