Antlrworks can help debug a grammar.
It works on a file (in this case generated by Xtext) with a '.g' extension, this is in the src-gen directory.
I went to:
and downloaded the 'antlrworks-1.5.jar' file.
I ran it as follows:
martin@linux-hr12:~> cd antlr martin@linux-hr12:~/antlr> java -jar antlrworks-1.5.jar
This brings up the following screen:
I clicked on 'Don't Send'
I don't want to create a new grammar but work on an existing one so I clicked cancel when the following wizard came up:
I then opened the '.g' file created by xtext.