In the tutorial of custom language support for Intellij Plugin development, it uses GrammarKit to generate the Parser and JFlex (patched) to generate the Lexer.
On this page the author says we can "use the GrammarKit plugin to generate lexer and parser".
Is there a particular reason that JetBrains suggest using JFlex to generate the lexer? How different the process would be if we use GrammarKit to generate both?