ARTICLE
Regular Expressions
ABAP supports extended regular
expressions in accordance with POSIX
standard 1003.2 . Regular expressions can be used after the addition
REGEX of the statements
FIND
REPLACE
as well as an argument of the following functions
count , count_...
contains_...
find , find_...
match
matches
replace
substring , substring_...
for searching and testing character strings. The classes
CL_ABAP_REGEX
CL_ABAP_MATCHER
permit object-oriented use of regular expressions.
A regular expression r is made up of literal characters and
special characters in accordance with the syntax
of regular expressions and represents a set of character strings. If
text is a character string represented by r , we say that
r matches text or that r fits text . Two
(different) regular expressions match if they fit the same set of
character strings.
If you apply a regular expression to a character string text as a
search string, then you are searching for matches of the regular
expression with substrings of text . In this case, special
characters in the regular expression do not match characters, but
instead match positions, thus influencing the type and number of
occurrences. When you test character strings, you
are checking whether the full content matches a pattern.
Notes
A regular expression can be syntactically correct, but too complex for
execution, which then raises a handleable exception of the
CX_SY_REGEX_TOO_COMPLEX class.
Refer to Exceptions in Regular Expressions .
The example program DEMO_REGEX and its
enhancement DEMO_REGEX_TOY enable you
to test the search and replace functions by using regular expressions on
texts.
Copyright Note
This software uses the Boost.Regex Library .
Copyright (c) 1998-2004 Dr. John Maddock.
Documentation extract taken from SAP system, � Copyright SAP AG. All rights reserved