The Idea plugin is a plugin for Idea that install the Antlr tool.
Create a grammar file with the extension g4 and Idea should propose you to install the Antlr plugin
Right click on your g4 file, you should see the Antlr option.
Antlr Recognizer run antlr.
Default run with the default configuration gives:
antlr4 ^
-o %ProjectRoot%\gen ^
-listener ^
-visitor ^
-lib %ProjectRoot%/src/main/antlr4/com/group/package/lexer ^ # output dir
%ProjectRoot%src/main/antlr4/grammar.g4
where:
The Configure Antlr are the options of antlr
Test a rule
start typing the text to see the tree in the Antlr panel