Re: [Axiom-developer] bug in write-to-string

[root]

In GCL 2.5.2 there is a bug that causes "Won't parse" messages in
the interpreter. A function called form2LispString in br-util.boot.pamphlet
calls STRINGIMAGE which is defined to be write-to-string in Common Lisp.

Inserting the vertical bar "|" escape character in strings breaks the
parsing within Axiom. Attached is the message to the GCL-devel list as
well as a patch file for vmlisp.lisp.pamphlet

===================================================================
--- vmlisp.lisp.pamphlet~       Sun Nov 17 14:14:45 2002
+++ vmlisp.lisp.pamphlet        Sun May 18 16:24:37 2003
@@ -8,6 +8,30 @@
 \end{abstract}
 \eject
 \tableofcontents
+\section{The StringImage Fix}
+In GCL 2.5 there is a bug in the write-to-string function.
+It should respect *print-escape* but it does not. That is,
+\begin{verbatim}
+
+In GCL 2.4.1:
+(setq *print-escape* nil)
+(write-to-string '|a|) ==> "a"
+
+In GCL 2.5:
+(setq *print-escape* nil)
+(write-to-string '|a|) ==> "|a|"
+
+\end{verbatim}
+The form2LispString function uses stringimage and fails.
+The princ-to-string function assumes *print-escape* is nil
+and works properly.
+
+<<stringimage fix>>=
+;(define-function 'prin2cvec #'write-to-string)
+(define-function 'prin2cvec #'princ-to-string)
+;(define-function 'stringimage #'write-to-string)
+(define-function 'stringimage #'princ-to-string)
+
 \eject
 <<*>>=
 ; See LICENSE.AXIOM for Copyright
@@ -1491,8 +1515,7 @@
 
 ; 24.0 Printing
 
-(define-function 'prin2cvec #'write-to-string)
-(define-function 'stringimage #'write-to-string)
+<<stringimage fix>>
 (define-function 'printexp #'princ)
 (define-function 'prin0  #'prin1)
 


===================================================================
In GCL 2.4.1:

(setq *print-escape* nil)
(write-to-string '|a|) ==> "a"

in GCL 2.5

(setq *print-escape* nil)
(write-to-string '|a|) ==> "|a|"

It appears that write-to-string is ignoring *print-escape*
in the latest version. This is a bug.

This causes the "Won't parse" messages in the latest port.

Tim