Visualize the Thompson-McNaughton-Yamada construction NFA for a given regular expression. The subset construction algorithm is also applied to the resultant NFA, resulting in a language-equivalent deterministic finite-state automata (DFA).Enter a regular expression: e.g. a*(b|cd)* ...
and you can transition from one node to another based on the next character in the input. For example, consider the simple expressionabc|cd. As a directed graph, this expression could look like this:
The two basic engine types reflect a fundamental difference in algorithms available for applying a regular expression to a string. I call the gasoline-driven NFA engine “regex-directed,” and the electric-driven DFA “text-directed.”NFA Engine: Regex-Directed...
Microsoft's .NET framework (including C#), has built in RE support through the System.Text.RegularExpression namespace. PHP with its built-in Perl-compatible RE functions or POSIX extended RE functions. Although being slightly different to use (because of the design of the languages), all are...
Microsoft's.NETframework (includingC#), has built in RE support through theSystem.Text.RegularExpressionnamespace. PHPwith its built-inPerl-compatible RE functionsorPOSIX extended RE functions. Although being slightly different to use (because of the design of the languages), all are quite similar...
9. The novel programming grammar of claim 3, wherein a normal (greedy from left-to-right) regular expression concatenation also uses the invented operator “>+” (greater than plus sign) in the C++ precedence table at the same position as the + operator and with exactly the same meaning ...