一. syntax error: ‘<’ came as a complete surprise to me while matching alternative

参考这个issue，antlr版本必须得是4.6
下载链接：http://www.antlr.org/download/antlr-4.6-complete.jar

二.org.antlr.v4.analysis.LeftRecursiveRuleTransformer.setAltASTPointers(LeftRecursiveRuleTransformer.java:241)

参考这个issue，Java版本必须得是Java6/7

三. antlr4运行命令

1. antlr4和grun永久配置别名

echo "alias antlr4='java -jar /usr/local/lib/antlr-4.0-complete.jar'" >> ~/.bashrc
echo "alias grun='java org.antlr.v4.runtime.misc.TestRig'" >> ~/.bashrc

2. 使用antlr4生成语法分析器和词法分析器

antlr4 test.g4

3. 编译生成的Java文件

javac *.java

4. 使用TestRig调试

grun [Grammar] [Rule] -options

eg. grun test r -tokens

四. 各种语言的.g4文件

https://github.com/antlr/grammars-v4/tree/master