Those who have written a compiler or parser once I think can understand what's token https://en.wikipedia.org/wiki/Context-free_grammar https://en.wikipedia.or

Those who have written a compiler or parser once I think can understand what's token https://en.wikipedia.org/wiki/Context-free_grammar https://en.wikipedia.org/wiki/Context-free_grammar https://en.wikipedia.org/wiki/Regular_grammar https://en.wikipedia.org/wiki/Regular_grammar