From: Fredrik Tolf <fredrik@dolda2000.com>
Date: Thu, 11 Mar 2010 20:07:47 +0000 (+0100)
Subject: Signal an error when a named codec could not be found.
X-Git-Url: http://dolda2000.com/gitweb/?p=lisp-utils.git;a=commitdiff_plain;h=c94c6f05729be13f1433925b0b95c363bb793284

Signal an error when a named codec could not be found.
---

diff --git a/charcode.lisp b/charcode.lisp
index dfe5a19..ac1c74d 100644
--- a/charcode.lisp
+++ b/charcode.lisp
@@ -4,13 +4,19 @@
 (defpackage :charcode
   (:use :cl #+sbcl :sb-gray #-sbcl :gray)
   (:export "MAKE-ENCODER" "MAKE-DECODER" "ENCODE-STRING" "DECODE-STRING" "SYSTEM-CHARSET"
-	   "CODING-ERROR"
+	   "NO-CODEC-ERROR" "CODING-ERROR"
 	   "MAKE-CODEC-CHARACTER-STREAM"
 	   "ASCII" "LATIN-1" "LATIN1" "UTF-8" "UTF8"))
 (in-package :charcode)
 
 ;;; General stuff
 
+(define-condition no-codec-error (error)
+  ((codec-name :initarg :codec-name))
+  (:report (lambda (c s)
+	     (with-slots (codec-name) c
+	       (format s "Could find no codec named ~A." codec-name)))))
+
 (define-condition coding-error (error)
   ((input :initarg :input)
    (position :initarg :position)
@@ -46,10 +52,12 @@
 	       synonyms)))
 
 (defun make-encoder (name)
-  (the encoder-fun (values (funcall (get name 'make-encoder)))))
+  (the encoder-fun (values (funcall (or (get name 'make-encoder)
+					(error 'no-codec-error :codec-name name))))))
 
 (defun make-decoder (name)
-  (the decoder-fun (values (funcall (get name 'make-decoder)))))
+  (the decoder-fun (values (funcall (or (get name 'make-decoder)
+					(error 'no-codec-error :codec-name name))))))
 
 (defun system-charset ()
   ;; XXX: Replace me with something perhaps more sensible.