Question

Which one of the following is a top-down parser?

(a) Recursive descent parser

(b) Operator precedence parser

(c) An LR(k) parser

(d) An LALR(k) parser

The question was asked during an interview.

My question is taken from Top-Down Parsing in section Topdown Parsing of Compiler

Answer 1

Right option is (a) Recursive descent parser

The best explanation: Recursive Descent also known as top down parsing also known to be LL(1).

 Consider the following two statements:

P: Every regular grammar is LL(1)

Q: Regular is LR(1) grammar.