Partially reverted previous commit.

parse/experimental/steal-box.rkt

@@ -1,3 +0,0 @@
-(module steal-box '#%kernel
-  (define-values (bx) (box #f))
-  (#%provide bx))

parse/experimental/steal-metafunction.rkt

@@ -1,59 +0,0 @@
-#lang racket
-
-;; Manages to grasp the template-metafunction via (namespace-mapped-symbols)
-;; within the eval.
-(module extracted-template-metafunction racket/base
-  (require (for-syntax syntax/parse/experimental/template)
-           (for-syntax racket/base)
-           (for-meta 2 racket/base)
-           (for-meta 2 stxparse-info/parse/experimental/steal-box))
-  (define-syntax (fu stx)
-    (syntax-case stx ()
-      [(_ id-mf? id-mf-v)
-       (let ()
-         (eval #'(begin
-                   (require (for-syntax
-                             stxparse-info/parse/experimental/steal-box))
-                   (define-template-metafunction (mf stx)
-                     #'1)
-                   (define-syntax (extract stx)
-                     ;; Use 3D syntax to return the value:
-                     (displayln (namespace-mapped-symbols))
-                     ;(displayln (eval 'template-metafunction))
-                     (define ctor (namespace-variable-value
-                                   (for/first ([sym (namespace-mapped-symbols)]
-                                               #:when (regexp-match #rx"template-metafunction[0-9].*" (symbol->string sym)))
-                                     sym)))
-                     (displayln (list ctor (ctor 5165163)))
-                     (displayln (template-metafunction? (syntax-local-value #'mf)))
-                     (set-box! bx template-metafunction?)
-                     #'(void)
-                     #;#`(values #,template-metafunction?
-                                 #,template-metafunction-var))
-                   (extract))
-               (module->namespace 'syntax/parse/experimental/template))
-         #`(begin
-             (define-for-syntax id-mf? 0)
-             (define-for-syntax id-mf-v 1)))]))
-  (fu out-id-mf? out-id-mf-v)
-  (begin-for-syntax
-    (define-for-syntax rsl bx))
-  
-  #;(begin-for-syntax
-      (define-syntax (br stx)
-        (displayln rsl)
-        #'(void))
-      (br))
-  #;(begin-for-syntax
-      (begin-for-syntax
-        (displayln rsl)))
-  (provide (for-meta 2 rsl #;out-id-mf? #;out-id-mf-v)))
-
-#;(require (rename-in (for-template 'extracted-template-metafunction)
-                      [out-id-mf? template-metafunction?]
-                      [out-id-mf-v template-metafunction-var]))
-(require (for-meta -2 'extracted-template-metafunction))
-(displayln rsl)
-
-#;(provide template-metafunction?
-           template-metafunction-var)

parse/experimental/steal-metafunction2.rkt

@@ -1,25 +0,0 @@
-#lang racket
-
-(require (for-syntax syntax/parse/experimental/template)
-         (for-syntax racket/base)
-         (for-meta 2 racket/base)
-         (for-meta 2 stxparse-info/parse/experimental/steal-box))
-
-(begin-for-syntax
-  (eval #'(begin (define-syntax (e2 stx)
-                   #`(begin
-                       (module #,(cdr (syntax-e stx)) racket
-                         (provide (for-syntax e4a e4b))
-                         ;(require syntax/parse/experimental/template)
-                         (define-for-syntax e4a #,template-metafunction?)
-                         (define-for-syntax e4b #,template-metafunction-var)
-                         (module* e5 racket/base
-                           (require (for-template (submod "..")))
-                           (provide e4a e4b)))))
-                 (e2 . e3))
-        (module->namespace 'syntax/parse/experimental/template))
-  (define e5a (dynamic-require '(submod 'e3 e5) 'e4a))
-  (define e5b (dynamic-require '(submod 'e3 e5) 'e4b))
-  (provide (rename-out [e5a template-metafunction?]
-                       [e5b template-metafunction-var])))
-

parse/experimental/template.rkt

@@ -16,64 +16,6 @@
          ??
          ?@)
 
-;; This is a bit ugly. Also, we can't extract the constructor for some reason
-;; (probably because it is a transformer binding, not a variable),
-;; so we require the original `define-template-metafunction` from
-;; syntax/parse/experimental/template to fulfill the defintition below.
-(require (only-in syntax/parse/experimental/template
-                  define-template-metafunction))
-(begin-for-syntax
-  (require "steal-metafunction.rkt")
-  (provide template-metafunction?
-           template-metafunction-var))
-#;(begin
-  (require (only-in syntax/parse/experimental/template
-                    define-template-metafunction))
-  (begin-for-syntax
-    (module extracted-template-metafunction racket/base
-      (require syntax/parse/experimental/template
-               (for-syntax racket/base))
-      (define-values (template-metafunction?
-                      ;template-metafunction
-                      template-metafunction-var)
-        (eval #'(begin
-                  (define-syntax (extract stx)
-                    ;; Use 3D syntax to return the value:
-                    #`(values #,template-metafunction?
-                              ;; Doesn't work, probably because it's a macro:
-                              ;#,template-metafunction
-                              #,template-metafunction-var))
-                  (extract))
-              (module->namespace 'syntax/parse/experimental/template)))
-      (provide template-metafunction?
-               ;template-metafunction
-               template-metafunction-var))
-
-    (require 'extracted-template-metafunction)
-    (provide template-metafunction?
-             template-metafunction-var)
-
-    ;; Tests:
-    #;(begin
-      (require rackunit)
-    
-      (require 'extracted-template-metafunction)
-      (require (for-meta 4 'extracted-template-metafunction))
-      (check-equal? (format "~a" template-metafunction?)
-                    "#<procedure:template-metafunction?>")
-          
-      (require (for-meta 1 racket/base))
-      (require (for-meta 2 racket/base))
-      (require (for-meta 3 racket/base))
-      (require (for-meta 4 racket/base))
-      (begin-for-syntax
-        (begin-for-syntax
-          (begin-for-syntax
-            (begin-for-syntax
-              (require rackunit)
-              (check-equal? (format "~a" template-metafunction?)
-                            "#<procedure:template-metafunction?>"))))))))
-
 #|
 To do:
 - improve error messages
@@ -244,7 +186,10 @@ instead of integers and integer vectors.
 ;; ============================================================
 
 
-#;(define-syntax (define-template-metafunction stx)
+;; TODO: once PR https://github.com/racket/racket/pull/1591 is merged, use
+;; the exported prop:template-metafunction, template-metafunction? and
+;; template-metafunction-accessor.
+(define-syntax (define-template-metafunction stx)
   (syntax-case stx ()
     [(dsm (id arg ...) . body)
      #'(dsm id (lambda (arg ...) . body))]
@@ -256,9 +201,7 @@ instead of integers and integer vectors.
                   (template-metafunction (quote-syntax internal-id)))))]))
 
 (begin-for-syntax
-  ;; This struct is not declared here, but instead extracted from the official
-  ;; syntax/parse/experimental/template, at the top of this file.
-  #;(struct template-metafunction (var)))
+ (struct template-metafunction (var)))
 
 ;; ============================================================
 

parse/experimental/test-steal.rkt

@@ -1,14 +0,0 @@
-#lang racket
-(require syntax/parse/experimental/template
-         stxparse-info/parse/experimental/steal-metafunction2)
-(define-template-metafunction (mf stx)
-  #'1)
-(provide mf)
-
-(let ()
-  (define-syntax (foo stx)
-    (displayln
-     (template-metafunction?
-      (syntax-local-value #'mf)))
-    #''ok)
-  (foo))

test/test-compatibility1.rkt

@@ -1,8 +1,6 @@
 #lang racket
-(require ;syntax/parse
-         ;syntax/parse/experimental/template
-         stxparse-info/parse
-         stxparse-info/parse/experimental/template)
+(require syntax/parse
+         syntax/parse/experimental/template)
 (provide mf original-template)
 (define-template-metafunction (mf stx)
   #'ok-metafunction-official-1)

test/test-compatibility2.rkt

@@ -1,23 +1,16 @@
 #lang racket
-(require ;syntax/parse
-         ;syntax/parse/experimental/template
-         stxparse-info/parse
+(require stxparse-info/parse
          stxparse-info/parse/experimental/template
          rackunit
-         #;"test-compatibility1.rkt")
-(define-template-metafunction (mf stx)
-  #'ok-metafunction-official-1)
+         "test-compatibility1.rkt")
 
+;; TODO: re-enable this, and do the test the other way round too
+;;       (the official syntax/parse to from stxparse-info)
 #;(check-equal? (syntax-parse #'(1 (2 3))
                   [(x {~optional y} ({~optional z} t))
-                   (list #;(syntax->datum
-                            (original-template (x (?? y no-y) (?? z no-z) t (mf))))
+                   (list (syntax->datum
+                          (original-template (x (?? y no-y) (?? z no-z) t (mf))))
                          (syntax->datum
                           (template (x (?? y no-y) (?? z no-z) t (mf)))))])
-                '(#;(1 no-y 2 3 ok-metafunction-official-1)
+                '((1 no-y 2 3 ok-metafunction-official-1)
                   (1 no-y 2 3 ok-metafunction-official-1)))
-
-(syntax-parse #'(1 (2 3))
-  [(x {~optional y} ({~optional z} t))
-   (syntax->datum
-    (template (x (?? y no-y) (?? z no-z) t (mf))))])