Steel Bank Common Lisp

Hans Huebner <hhuebner@...> writes:

> on the Gray streams example page, there is this nice input stream class 
> that counts lines and characters 
> (http://www.sbcl.org/manual/Character-counting-input-stream.html).  I 
> tried using it, but the read-line methods seemed to be missing 

(Speaking as the person who wrote that bit of the manual) Leaving out
the stream-read-line method was intentional: I wanted to minimal
examples of the Gray Streams protocols.  But there is a bug:
wrapped-character-input-stream is supposed to be a subclass of
fundamental-character-input-stream, for which there's an adequate
default method on stream-read-line.

> ... and read-char of the real stream was called with eof-error-p
> defaulted to t, which is not good, I think.

This is also a bug.

SBCL developers: the patch below corrects the errors in the example
code.

--
RmK


Index: doc/manual/gray-streams-examples.texinfo
===================================================================
RCS file: /cvsroot/sbcl/sbcl/doc/manual/gray-streams-examples.texinfo,v
retrieving revision 1.1
diff -u -r1.1 gray-streams-examples.texinfo
--- doc/manual/gray-streams-examples.texinfo	20 Dec 2006 15:50:51 -0000	1.1
+++ doc/manual/gray-streams-examples.texinfo	13 Apr 2007 15:18:05 -0000
@@ -47,13 +47,14 @@
 @end group
 
 @group
-(defclass wrapped-character-input-stream (wrapped-stream)
+(defclass wrapped-character-input-stream
+    (wrapped-stream fundamental-character-output-stream)
   ())
 @end group
 
 @group
 (defmethod stream-read-char ((stream wrapped-character-input-stream))
-  (read-char (stream-of stream)))
+  (read-char (stream-of stream) nil :eof))
 @end group
 
 @group

Richard M Kreuter <kreuter@...> writes:

> Hans Huebner <hhuebner@...> writes:
>
>> on the Gray streams example page, there is this nice input stream class 
>> that counts lines and characters 
>> (http://www.sbcl.org/manual/Character-counting-input-stream.html).  I 
>> tried using it, but the read-line methods seemed to be missing 
>
> (Speaking as the person who wrote that bit of the manual) Leaving out
> the stream-read-line method was intentional: I wanted to minimal
> examples of the Gray Streams protocols.  But there is a bug:
> wrapped-character-input-stream is supposed to be a subclass of
> fundamental-character-input-stream, for which there's an adequate
> default method on stream-read-line.
>
> SBCL developers: the patch below corrects the errors in the example
> code.
> [...]

> -(defclass wrapped-character-input-stream (wrapped-stream)
> +(defclass wrapped-character-input-stream
> +    (wrapped-stream fundamental-character-output-stream)

This doesn't look right.  I'm going to take an executive decision and
assume that you meant fundamental-character-input-stream here in my
next commit.

Best,

Christophe

Christophe Rhodes <csr21@...> writes:
> Richard M Kreuter <kreuter@...> writes:

>> wrapped-character-input-stream is supposed to be a subclass of
>> fundamental-character-input-stream, for which there's an adequate
>> default method on stream-read-line.
>>
>> SBCL developers: the patch below corrects the errors in the example
>> code.
>> [...]
>
>> -(defclass wrapped-character-input-stream (wrapped-stream)
>> +(defclass wrapped-character-input-stream
>> +    (wrapped-stream fundamental-character-output-stream)
>
> This doesn't look right.  I'm going to take an executive decision and
> assume that you meant fundamental-character-input-stream here in my
> next commit.

Yes, sorry, this was a paste-o.

--
Richard