repl read/write using current ports, not captured ports

Fixes bug in repl meta-commands after activating readline, which changes
the current input port.

* module/system/repl/common.scm (<repl>): Remove inport and outport
  fields.
  (make-repl): Adapt.
  (repl-read, repl-print): Just read and write to the current ports.

* module/system/repl/repl.scm (meta-reader): Meta-read from the current
  input port.

* module/system/repl/command.scm (read-command, define-meta-command):
  Read from the current input port.

module/system/repl/command.scm

@@ -136,7 +136,7 @@
 
 (define (read-command repl)
   (catch #t
-    (lambda () (read (repl-inport repl)))
+    (lambda () (read))
     (lambda (key . args)
       (pmatch args
         ((,subr ,msg ,args . ,rest)
@@ -148,11 +148,6 @@
       (force-output)
       *unspecified*)))
 
-(define read-line
-  (let ((orig-read-line read-line))
-    (lambda (repl)
-      (orig-read-line (repl-inport repl)))))
-
 (define (meta-command repl)
   (let ((command (read-command repl)))
     (cond
@@ -183,19 +178,19 @@
        (% (let* ((expression0
                   (catch #t
                     (lambda ()
-                      (repl-reader ""
+                      (repl-reader
-                                   (lambda* (#:optional (port (repl-inport repl)))
+                       ""
-                                     ((language-reader (repl-language repl))
+                       (lambda* (#:optional (port (current-input-port)))
-                                      port (current-module)))))
+                         ((language-reader (repl-language repl))
+                          port (current-module)))))
                     (lambda (k . args)
                       (handle-read-error 'expression0 k args))))
                  ...)
             (apply (lambda* datums
-                     (with-output-to-port (repl-outport repl)
+                     b0 b1 ...)
-                       (lambda () b0 b1 ...)))
                    (catch #t
                      (lambda ()
-                       (let ((port (open-input-string (read-line repl))))
+                       (let ((port (open-input-string (read-line))))
                          (let lp ((out '()))
                            (let ((x (read port)))
                              (if (eof-object? x)

module/system/repl/common.scm

@@ -26,7 +26,7 @@
   #:use-module (ice-9 control)
   #:use-module (ice-9 history)
   #:export (<repl> make-repl repl-language repl-options
-            repl-tm-stats repl-gc-stats repl-inport repl-outport repl-debug
+            repl-tm-stats repl-gc-stats repl-debug
             repl-welcome repl-prompt
             repl-read repl-compile repl-prepare-eval-thunk repl-eval
             repl-parse repl-print repl-option-ref repl-option-set!
@@ -102,7 +102,7 @@ See <http://www.gnu.org/licenses/lgpl.html>, for more details.")
 ;;;
 
 (define-record/keywords <repl>
-  language options tm-stats gc-stats inport outport debug)
+  language options tm-stats gc-stats debug)
 
 (define repl-default-options
   (copy-tree
@@ -128,8 +128,6 @@ See <http://www.gnu.org/licenses/lgpl.html>, for more details.")
               #:options (copy-tree repl-default-options)
               #:tm-stats (times)
               #:gc-stats (gc-stats)
-              #:inport (current-input-port)
-              #:outport (current-output-port)
               #:debug debug))
 
 (define (repl-welcome repl)
@@ -151,8 +149,8 @@ See <http://www.gnu.org/licenses/lgpl.html>, for more details.")
               (if (zero? level) "" (format #f " [~a]" level)))))))
 
 (define (repl-read repl)
-  ((language-reader (repl-language repl)) (repl-inport repl)
+  (let ((reader (language-reader (repl-language repl))))
-                                          (current-module)))
+    (reader (current-input-port) (current-module))))
 
 (define (repl-compile-options repl)
   (repl-option-ref repl 'compile-options))
@@ -187,8 +185,8 @@ See <http://www.gnu.org/licenses/lgpl.html>, for more details.")
         ;; should be printed with the generic printer, `write'. The
         ;; language-printer is something else: it prints expressions of
         ;; a given language, not the result of evaluation.
-	(write val (repl-outport repl))
+	(write val)
-	(newline (repl-outport repl)))))
+	(newline))))
 
 (define (repl-option-ref repl key)
   (cadr (or (assq key (repl-options repl))

module/system/repl/repl.scm

@@ -63,20 +63,19 @@
 (define meta-command-token (cons 'meta 'command))
 
 (define (meta-reader read env)
-  (lambda read-args
+  (lambda* (#:optional (port (current-input-port)))
-    (let ((port (if (pair? read-args) (car read-args) (current-input-port))))
+    (with-input-from-port port
-      (with-input-from-port port
+      (lambda ()
-        (lambda ()
+        (let ((ch (next-char #t)))
-          (let ((ch (next-char #t)))
+          (cond ((eof-object? ch)
-            (cond ((eof-object? ch)
+                 ;; EOF objects are not buffered. It's quite possible
-                   ;; EOF objects are not buffered. It's quite possible
+                 ;; to peek an EOF then read something else. It's
-                   ;; to peek an EOF then read something else. It's
+                 ;; strange but it's how it works.
-                   ;; strange but it's how it works.
+                 ch)
-                   ch)
+                ((eqv? ch #\,)
-                  ((eqv? ch #\,)
+                 (read-char port)
-                   (read-char port)
+                 meta-command-token)
-                   meta-command-token)
+                (else (read port env))))))))
-                  (else (read port env)))))))))
         
 ;; repl-reader is a function defined in boot-9.scm, and is replaced by
 ;; something else if readline has been activated. much of this hoopla is