Merge remote-tracking branch 'origin/stable-2.0'

Conflicts:
	configure.ac

module/srfi/srfi-39.scm

@@ -35,104 +35,19 @@
 ;;; Code:
 
 (define-module (srfi srfi-39)
-  #:use-module (srfi srfi-16)
-
-  #:export (make-parameter)
-  #:export-syntax (parameterize)
-
   ;; helper procedure not in srfi-39.
   #:export (with-parameters*)
-  #:replace (current-input-port current-output-port current-error-port))
+  #:re-export (make-parameter
+               parameterize
+               current-input-port current-output-port current-error-port))
 
-;; Make 'srfi-39 available as a feature identifiere to `cond-expand'.
-;;
-(cond-expand-provide (current-module) '(srfi-39))
-
-(define make-parameter
-  (case-lambda
-    ((val) (make-parameter/helper val (lambda (x) x)))
-    ((val conv) (make-parameter/helper val conv))))
-
-(define get-fluid-tag (lambda () 'get-fluid)) ;; arbitrary unique (as per eq?) value
-(define get-conv-tag (lambda () 'get-conv)) ;; arbitrary unique (as per eq?) value
-
-(define (make-parameter/helper val conv)
-  (let ((fluid (make-fluid (conv val))))
-    (case-lambda
-      (()
-       (fluid-ref fluid))
-      ((new-value)
-       (cond
-        ((eq? new-value get-fluid-tag) fluid)
-        ((eq? new-value get-conv-tag) conv)
-        (else (fluid-set! fluid (conv new-value))))))))
-
-(define-syntax-rule (parameterize ((?param ?value) ...) ?body ...)
-  (with-parameters* (list ?param ...)
-                    (list ?value ...)
-                    (lambda () ?body ...)))
-
-(define current-input-port
-  (case-lambda
-    (()
-     ((@ (guile) current-input-port)))
-    ((new-value)
-     (set-current-input-port new-value))))
-
-(define current-output-port
-  (case-lambda
-    (()
-     ((@ (guile) current-output-port)))
-    ((new-value)
-     (set-current-output-port new-value))))
-
-(define current-error-port
-  (case-lambda
-    (()
-     ((@ (guile) current-error-port)))
-    ((new-value)
-     (set-current-error-port new-value))))
-
-(define port-list
-  (list current-input-port current-output-port current-error-port))
-
-;; There are no fluids behind current-input-port etc, so those parameter
-;; objects are picked out of the list and handled separately with a
-;; dynamic-wind to swap their values to and from a location (the "value"
-;; variable in the swapper procedure "let").
-;;
-;; current-input-port etc are already per-dynamic-root, so this arrangement
-;; works the same as a fluid.  Perhaps they could become fluids for ease of
-;; implementation here.
-;;
-;; Notice the use of a param local variable for the swapper procedure.  It
-;; ensures any application changes to the PARAMS list won't affect the
-;; winding.
-;;
 (define (with-parameters* params values thunk)
   (let more ((params params)
 	     (values values)
 	     (fluids '())     ;; fluids from each of PARAMS
-	     (convs  '())     ;; VALUES with conversion proc applied
-	     (swapper noop))  ;; wind/unwind procedure for ports handling
+	     (convs  '()))    ;; VALUES with conversion proc applied
     (if (null? params)
-	(if (eq? noop swapper)
-	    (with-fluids* fluids convs thunk)
-	    (dynamic-wind
-		swapper
-		(lambda ()
-		  (with-fluids* fluids convs thunk))
-		swapper))
-	(if (memq (car params) port-list)
-	    (more (cdr params) (cdr values)
-		  fluids convs
-		  (let ((param (car params))
-			(value (car values))
-			(prev-swapper swapper))
-		    (lambda ()
-		      (set! value (param value))
-		      (prev-swapper))))
-	    (more (cdr params) (cdr values)
-		  (cons ((car params) get-fluid-tag) fluids)
-		  (cons (((car params) get-conv-tag) (car values)) convs)
-		  swapper)))))
+	(with-fluids* fluids convs thunk)
+        (more (cdr params) (cdr values)
+              (cons (parameter-fluid (car params)) fluids)
+              (cons ((parameter-converter (car params)) (car values)) convs)))))