Update the version of Bison that ships with OSX

brew install bison

Build and run parser against test.txt:

bison --defines=src/parser.tab.h --output=src/parser.tab.c src/parser.y
flex --outfile=src/lex.yy.c src/lexer.l
cc src/parser.tab.c src/lex.yy.c -o test
./test

Debug Bison grammar file by observing parser.output via:

bison -d --report=state src/parser.y
cat parser.output | grep conflict

Conflicts

Set %right ASSIGN back to %token ASSIGN to generate a conflict.

Rust

Install Rust

curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh  # Choose 1 when prompted
source $HOME/.cargo/env

Build & run module that wraps the Flex/Bison C code

cargo build
cargo run