问题:

I'm new using Antlr4 but I know that exist a plugin for Eclipse. I have a simple question...After I created the g4 file how can I visualize the live parse tree in order to see the tree of an input expression? Thanks

回答1:

Currently there is no provision for viewing live parse tree in ANTLR 4 IDE for Eclipse.

Meanwhile, you can see the parse tree using -gui switch in the command line. It also provides a feature of saving the parse tree as PNG.

回答2:

After installing Antlr4Ide plugin in Eclipse:

Window>Show View>Other, Antlr4>Parse tree
Activate g4 file
Click parsing rule in g4 file, Parse tree now shows active rule above source editor box

In the parse tree view you see a live source editor on the left, with syntax highlighting for your language. When you enter code in your language there, the tree will update on the right. The antlr console shows parsing errors at the same time.