From: Geoff Voelker <voelker@cs.washington.edu>
Date: Sun, 20 Jul 1997 01:31:41 +0000 (+0000)
Subject: (modify-coding-system-alist): Moved to mule-util.el.
X-Git-Tag: emacs-20.1~1072
X-Git-Url: http://git.eshelyaron.com/gitweb/?a=commitdiff_plain;h=fe831d33c5f276636f6ea8ba8e1b72bae5eafa51;p=emacs.git

(modify-coding-system-alist): Moved to mule-util.el.
---

diff --git a/lisp/international/mule.el b/lisp/international/mule.el
index c28cf485afb..e1381488ef8 100644
--- a/lisp/international/mule.el
+++ b/lisp/international/mule.el
@@ -630,6 +630,58 @@ Return nil if there's no need of setting new buffer-file-coding-system."
 		  (aref (coding-system-eol-type new-coding) new-eol)))
 	new-coding))))
 
+(defun modify-coding-system-alist (target-type regexp coding-system)
+  "Modify one of look up tables for finding a coding system on I/O operation.
+There are three of such tables, file-coding-system-alist,
+process-coding-system-alist, and network-coding-system-alist.
+
+TARGET-TYPE specifies which of them to modify.
+If it is `file', it affects file-coding-system-alist (which see).
+If it is `process', it affects process-coding-system-alist (which see).
+If it is `network', it affects network-codign-system-alist (which see).
+
+REGEXP is a regular expression matching a target of I/O operation.
+The target is a file name if TARGET-TYPE is `file', a program name if
+TARGET-TYPE is `process', or a network service name or a port number
+to connect to if TARGET-TYPE is `network'.
+
+CODING-SYSTEM is a coding system to perform code conversion on the I/O
+operation, or a cons of coding systems for decoding and encoding
+respectively, or a function symbol which returns the cons."
+  (or (memq target-type '(file process network))
+      (error "Invalid target type: %s" target-type))
+  (or (stringp regexp)
+      (and (eq target-type 'network) (integerp regexp))
+      (error "Invalid regular expression: %s" regexp))
+  (if (symbolp coding-system)
+      (if (not (fboundp coding-system))
+	  (progn
+	    (check-coding-system coding-system)
+	    (setq coding-system (cons coding-system coding-system))))
+    (check-coding-system (car coding-system))
+    (check-coding-system (cdr coding-system)))
+  (cond ((eq target-type 'file)
+	 (let ((slot (assoc regexp file-coding-system-alist)))
+	   (if slot
+	       (setcdr slot coding-system)
+	     (setq file-coding-system-alist
+		   (cons (cons regexp coding-system)
+			 file-coding-system-alist)))))
+	((eq target-type 'process)
+	 (let ((slot (assoc regexp process-coding-system-alist)))
+	   (if slot
+	       (setcdr slot coding-system)
+	     (setq process-coding-system-alist
+		   (cons (cons regexp coding-system)
+			 process-coding-system-alist)))))
+	(t
+	 (let ((slot (assoc regexp network-coding-system-alist)))
+	   (if slot
+	       (setcdr slot coding-system)
+	     (setq network-coding-system-alist
+		   (cons (cons regexp coding-system)
+			 network-coding-system-alist)))))))
+
 (defun make-unification-table (&rest args)
   "Make a unification table (char table) from arguments.
 Each argument is a list of the form (FROM . TO),