You need to install ANTLR4.
To compile run:
javac -cp antlr-4.13.1-complete.jar *.java
Use whatever the actual path of the ANTLR complete jar file is.
And then:
java Main.java
You can put your code in input.txt
output("Hello world!");
int a = 10;
str b = "bar";
float c = 3.14;
bool d = True;
e = 2 + 2;
Outputting a string includes the double quotes (I will fix this).