Use ANTLR to generate the parser for the grammar Expr.g4.
Generate D code (-Dlanguage=D) in the source directory (-o src).
And generate a visitor (-visitor) instead of a listener (-no-listener).
antlr4 -Dlanguage=D -o src -visitor -no-listener Expr.g4
You need src/main.d and src/calc.d to set up the parser and to provide a visitor implementation that evaluates arithmetic expressions.
Use dub to run, build, or test the application. For example:
dub run -- test.expr
echo '1 + 2 * 3' | dub run
Or build the application and then run it:
dub build
./expr test.expr
echo '1 + 2 * 3' | ./expr
If you want to see all the ANTLR debug output, build the application like this:
dub build --build=antlr-debug
Build a unittest runner and let it run:
dub test