The subset LALR(1) is pretty simple. Table with states that can shift or reduce, and finally accept or error. It's not too hard to get the dragon book and wri

The subset LALR(1) is pretty simple. Table with states that can shift or reduce, and finally accept or error. It's not too hard to get the dragon book and write an LALR(1) parser for a calculator by hand. Plenty of lectures out there that explain it. If I can write a lexer/parser from scratch after hearing the explanation of LALR(1), anyone can. LR(k) would be more complicated. Start with the smaller CFG subset and work up to it.