Accept parameters in #lang preserves-schema lines

implementations/racket/preserves/preserves-schema/bin/preserves-schema-rkt.rkt

@@ -2,7 +2,7 @@
 
 (provide batch-compile load-plugins)
 
-(require "../main.rkt")
+(require "../compiler.rkt")
 (require "../reader.rkt")
 (require racket/match)
 (require racket/pretty)

implementations/racket/preserves/preserves-schema/main.rkt

@@ -6,13 +6,28 @@
 
 (module+ reader
   (provide (rename-out [read-preserves-schema-module read-syntax]))
+  (require racket/match)
   (require (only-in "reader.rkt" port->schema))
+  (require (only-in racket/port port->list))
+  (require (only-in "bin/preserves-schema-rkt.rkt" load-plugins))
   (define (read-preserves-schema-module src [p (current-input-port)])
     (define-values (_dirname filename _must-be-dir) (split-path src))
+    (define plugin-modules '())
+    (let loop ((params (port->list read (open-input-string (read-line p)))))
+      (match params
+        ['()
+         (void)]
+        [(list* '#:plugin modname more)
+         (set! plugin-modules (cons modname plugin-modules))
+         (loop more)]
+        [other
+         (raise-syntax-error #f "Invalid #lang preserves-schema parameters: ~v" other)]))
+    (define plugins (load-plugins plugin-modules))
     (schema->module-stx
      (string->symbol (path->string (path-replace-extension filename "")))
      (lambda (module-path) #f)
      (port->schema src p)
+     #:plugins plugins
      #:translation-paths (schema-translation-paths src
                                                    filename
                                                    #f