Merge pull request #7 from jsmaniac/reqprov

Adds require and provide transformers expander-in and expander-out

main.rkt

@@ -4,3 +4,4 @@
 "private/define-expanders.rkt"
 "private/scoped-transformers.rkt"
 "private/define-scoped-transformers.rkt"
+"private/reqprov.rkt"

main.scrbl

@@ -25,3 +25,4 @@ extensible.
 @include-section["private/define-expanders.scrbl"]
 @include-section["private/scoped-transformers.scrbl"]
 @include-section["private/define-scoped-transformers.scrbl"]
+@include-section["private/reqprov.scrbl"]

private/reqprov.rkt

@@ -0,0 +1,34 @@
+#lang racket/base
+
+(require racket/require-syntax
+         racket/provide-syntax
+         (for-syntax racket/base
+                     racket/provide-transform
+                     racket/syntax
+                     syntax/parse))
+
+(provide expander-in
+         expander-out)
+
+(define-for-syntax (reqprov-transformer2 id combiner prefix)
+  (with-syntax
+      ([id-expander-type (format-id id "~a-expander-type" id)]
+       [make-id-expander (format-id id "make-~a-expander" id)]
+       [id-expander? (format-id id "~a-expander?" id)]
+       [define-id-expander (format-id id "define-~a-expander" id)]
+       [expand-all-id-expanders (format-id id "expand-all-~a-expanders" id)])
+    #`(#,combiner (for-syntax (#,@prefix id-expander-type))
+                  (for-syntax (#,@prefix make-id-expander))
+                  (for-syntax (#,@prefix id-expander?))
+                  (#,@prefix define-id-expander)
+                  (for-syntax (#,@prefix expand-all-id-expanders)))))
+
+(define-require-syntax expander-in
+  (syntax-parser
+    [(_ require-spec id:id)
+     (reqprov-transformer2 #'id #'combine-in #'(only-in require-spec))]))
+
+(define-provide-syntax expander-out
+  (syntax-parser
+    [(_ id:id)
+     (reqprov-transformer2 #'id #'combine-out #'(combine-out))]))

private/reqprov.scrbl

@@ -0,0 +1,27 @@
+#lang scribble/manual
+@(require "doc-util.rkt")
+
+@title{@racket[require] and @racket[provide] transformers}
+
+@defform[#:kind "require transformer"
+         (expander-in require-spec id)]{
+ This @techlink[#:doc '(lib "scribblings/reference/reference.scrbl")]{
+  require transformer} imports from @racket[require-spec]
+ the identifiers defined by 
+ @racket[(define-expander-type id)]:
+ @itemlist[@item{@tt{@emph{id}-expander-type}}
+           @item{@tt{make-@emph{id}-expander}}
+           @item{@tt{@emph{id}-expander?}}
+           @item{@tt{define-@emph{id}-expander}}
+           @item{@tt{expand-all-@emph{id}-expanders}}]}
+
+@defform[#:kind "provide transformer"
+         (expander-out id)]{
+ This @techlink[#:doc '(lib "scribblings/reference/reference.scrbl")]{
+  provide transformer} exports the identifiers defined by
+ @racket[(define-expander-type id)]:
+ @itemlist[@item{@tt{@emph{id}-expander-type}}
+           @item{@tt{make-@emph{id}-expander}}
+           @item{@tt{@emph{id}-expander?}}
+           @item{@tt{define-@emph{id}-expander}}
+           @item{@tt{expand-all-@emph{id}-expanders}}]}