My notes for project Breccia      regular-expression pattern matching      / Based on the standard of Perl, not PCRE. No standard in itself, PCRE is merely C’s implementation of the Perl standard.      - The pattern language must include just those formal elements of Perl supported (whether directly or through a translational preprocessor) by the regular-expression engines of the major programming languages and text editors.      : see https://stackoverflow.com/a/1448213/2402790      - My proxies for the latter are Java and Emacs.