[Guile-commits] branch main updated: Doc: clarification on regexes and encodings

[Arne Babenhauserheide]

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The following commit(s) were added to refs/heads/main by this push:
     new ff165ec90 Doc: clarification on regexes and encodings
ff165ec90 is described below

commit ff165ec9040cce0aa7a9aac0ca44743b7c1186a3
Author: Jean Abou Samra <jean@abou-samra.fr>
AuthorDate: Sun Dec 11 12:28:02 2022 +0100

    Doc: clarification on regexes and encodings
    
    * doc/ref/api-regex.texi: make it more obviously clear that regexp
      matching supports only characters supported by the locale encoding.
---
 doc/ref/api-regex.texi | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/doc/ref/api-regex.texi b/doc/ref/api-regex.texi
index b14c2b39c..d778f969f 100644
--- a/doc/ref/api-regex.texi
+++ b/doc/ref/api-regex.texi
@@ -57,7 +57,11 @@ locale's encoding, and then passed to the C library's 
regular expression
 routines (@pxref{Regular Expressions,,, libc, The GNU C Library
 Reference Manual}).  The returned match structures always point to
 characters in the strings, not to individual bytes, even in the case of
-multi-byte encodings.
+multi-byte encodings.  This ensures that the match structures are
+correct when performing matching with characters that have a multi-byte
+representation in the locale encoding.  Note, however, that using
+characters which cannot be represented in the locale encoding can
+lead to surprising results.
 
 @deffn {Scheme Procedure} string-match pattern str [start]
 Compile the string @var{pattern} into a regular expression and compare
@@ -325,7 +329,7 @@ example the following is the date example from
 @code{string-match} call.
 
 @lisp
-(define date-regex 
+(define date-regex
    "([0-9][0-9][0-9][0-9])([0-9][0-9])([0-9][0-9])")
 (define s "Date 20020429 12am.")
 (regexp-substitute/global #f date-regex s