X-Git-Url: http://dolda2000.com/gitweb/?p=lisp-utils.git;a=blobdiff_plain;f=charcode.lisp;h=1d52daee3590af807a98ea6b5f21492b7749bf5d;hp=68ef0def97dbf270f04753879c00d35ec23098bd;hb=4dd02a73cffd7edaa90aebf6641b5779af2fdbcf;hpb=ebf1ccf75c98bbaf66b39e126d92aa43aaf255f3

diff --git a/charcode.lisp b/charcode.lisp
index 68ef0de..1d52dae 100644
--- a/charcode.lisp
+++ b/charcode.lisp
@@ -3,10 +3,10 @@
 
 (defpackage :charcode
   (:use :cl #+sbcl :sb-gray #-sbcl :gray)
-  (:export "MAKE-ENCODER" "MAKE-DECODER" "ENCODE-STRING" "DECODE-STRING"
+  (:export "MAKE-ENCODER" "MAKE-DECODER" "ENCODE-STRING" "DECODE-STRING" "SYSTEM-CHARSET"
 	   "CODING-ERROR"
 	   "MAKE-CODEC-CHARACTER-STREAM"
-	   "LATIN-1" "LATIN1" "UTF-8" "UTF8"))
+	   "ASCII" "LATIN-1" "LATIN1" "UTF-8" "UTF8"))
 (in-package :charcode)
 
 ;;; General stuff
@@ -51,7 +51,11 @@
 (defun make-decoder (name)
   (the decoder-fun (values (funcall (get name 'make-decoder)))))
 
-(defun encode-string (string coding)
+(defun system-charset ()
+  ;; XXX: Replace me with something perhaps more sensible.
+  'utf-8)
+
+(defun encode-string (string &optional (coding (system-charset)))
   (declare (type string string))
   (let ((encoder (make-encoder coding))
 	(buf (make-array (list (length string)) :element-type '(unsigned-byte 8) :adjustable t :fill-pointer 0)))
@@ -59,7 +63,7 @@
       (coding-error string (length string) buf "Encoding of string in ~A ended prematurely." coding))
     buf))
 
-(defun decode-string (buffer coding)
+(defun decode-string (buffer &optional (coding (system-charset)))
   (declare (type (array (unsigned-byte 8)) buffer))
   (let ((decoder (make-decoder coding))
 	(buf (make-array (list (length buffer)) :element-type 'character :adjustable t :fill-pointer 0)))
@@ -76,7 +80,7 @@
    (read-pos :initform 0)
    (buffer :initform (make-array '(64) :element-type 'character :adjustable t :fill-pointer 0))))
 
-(defun make-codec-character-stream (real-stream charset)
+(defun make-codec-character-stream (real-stream &optional (charset (system-charset)))
   (declare (type stream real-stream))
   (make-instance 'codec-character-stream :decoder (make-decoder charset) :encoder (make-encoder charset) :back real-stream))
 
@@ -191,6 +195,53 @@
   (declare (type character char))
   (char-code char))
 
+;;; ASCII
+
+(defun decode-ascii (byteseq charseq &key (start 0) (end (length byteseq)))
+  (declare (type (array (unsigned-byte 8)) byteseq)
+	   (type (array character) charseq)
+	   (type fixnum start end))
+  (loop
+     (restart-case
+	 (loop
+	    (unless (< start end) (return-from decode-ascii t))
+	    (let ((byte (aref byteseq (prog1 start (incf start)))))
+	      (unless (< byte 128)
+		(coding-error byteseq start charseq "Invalid byte ~D in ASCII stream." byte))
+	      (vector-push-extend (unicode->char byte) charseq)))
+       (:replace-char (&optional (replacement (unicode->char #xfffd)))
+	 :report "Replace the invalid byte with a character."
+	 (vector-push-extend replacement charseq))
+       (:skip-char ()
+	 :report "Ignore the invalid byte."
+	 nil))))
+
+(defun encode-ascii (charseq byteseq &key (start 0) (end (length charseq)))
+  (declare (type (array (unsigned-byte 8)) byteseq)
+	   (type (array character) charseq)
+	   (type fixnum start end))
+  (loop
+     (restart-case
+	 (loop
+	    (unless (< start end) (return-from encode-ascii t))
+	    (vector-push-extend (let ((cp (char->unicode (aref charseq (prog1 start (incf start))))))
+				  (unless (< cp 128)
+				    (coding-error charseq start byteseq "ASCII cannot encode code-points higher than 128."))
+				  cp)
+				byteseq))
+       (:replace-char (&optional (replacement #\?))
+	 :report "Replace this character with another."
+	 (vector-push-extend (char->unicode replacement) byteseq))
+       (:skip-char ()
+	 :report "Ignore this character."
+	 nil))))
+
+(define-decoder (ascii)
+  #'decode-ascii)
+
+(define-encoder (ascii)
+  #'encode-ascii)
+
 ;;; Latin-1
 
 (defun decode-latin-1 (byteseq charseq &key (start 0) (end (length byteseq)))