useful.txt

# get java

# get homebrew

# get ANTLR
brew update; brew install antlr

# regenerate recogniser java source files for latest antlr
cd directory-containing-this
antlr4 -o src -Dlanguage=Java -listener -visitor Java8.g4

# build the source without an IDE
cd directory-containing-this
mkdir out/production/J2S
javac -cp "/usr/local/Cellar/antlr/4.6/antlr-4.6-complete.jar:." -d out/production/J2S src/*.java

# use the binaries to convert a java file
src_file=path-to-your-source-file
dst_file="${src_file%\.*}.swift"
cd directory-containing-this
J2S="$(pwd)/out/production/J2S"
java -cp "/usr/local/Cellar/antlr/4.6/antlr-4.6-complete.jar:${J2S}:." J2S "${src_file}" > "${dst_file}"



# Misc

# Regex to create listener stubs from grammar
:Find:
(^(\s*)([a-z])(\w+)\n(.+\n)+?\s*;$)
:Replace with:
$2/*
$1
$2@Override public void enter\u$3$4( Java8Parser.\u$3$4Context ctx ) { }
$2@Override public void exit\u$3$4( Java8Parser.\u$3$4Context ctx ) { }
$2*/

# Regex to create visitor stubs from grammar (substitute your visitor return type for T)
:Find:
(^(\s*)([a-z])(\w+)\n(.+\n)+?\s*;$)
:Replace with:
$2/*
$1
$2@Override public T visit\u$3$4( Java8Parser.\u$3$4Context ctx ) { return visitChildren(ctx); }
$2*/