Introduction to Regular Expressions

APLX includes facilities for string search using regular expressions, which are strings that can be used to match patterns within other strings, according to certain syntax rules. Regular expressions can be used in the Find/Change dialog in an editor or session window, in the Search Workspace dialog, and in your APL code using the ⎕SS String Search/Replace system function. This provides a powerful extension to the APL language, since regular expressions can be used to do sophisticated searches using a very compact notation.

For an introduction to Regular Expressions, please consult one of the many books or web-sites on the subject, for example www.regular-expressions.info

The implementation of regular-expression searching in APLX is based on version 7.1 of Perl Compatible Regular Expressions (PCRE), an open-source product written by Philip Hazel of the University of Cambridge.

The next section describes the regular-expression syntax in detail.