Regex Editor & Tester

Validates lines composed of 'sentences': sequences of words (any characters except spaces, periods, CR/LF, or parentheses) separated by single spaces and terminated by a period. Also matches parenthesized word groups as standalone items, permits multiple space-separated sentences per line, and accepts empty lines. Uses PCRE subroutine calls (\g<W>, \g<S>) to recursively reuse the word and sentence subpatterns.