By contrast , traditional parser generators like yacc use LALR ( 1 ) parser tables to construct a restricted LR parser with a fixed one - token lookahead .
Moreover , in certain cases LL parsing is feasible even with unlimited lookahead .
Traditional parser generators like yacc use LALR ( 1 ) parser tables to construct a restricted LR parser with a fixed one - token lookahead .
Moreover , in certain cases LL parsing is feasible even with unlimited lookahead .