Question

Which one of the following is a top-down parser ?
1. Recursive descent parser
2. Shift left associative parser
3. SLR (k) parser 
4. LR (k) parser

Answer 1

Correct Answer - Option 1 : Recursive descent parser

The correct answer is option 1

• A top-down parsing technique parses the input by starts constructing a parse tree from the root node moving down to the leaf nodes.
• A top-down parser uses the leftmost derivation to generate the string. 
• A recursive descent parser is a top-down parser

Parser	Derivation
LR parsers or Bottom-up Parsers	Rightmost reverse Derivation
LL parsers or Top-down Parsers	Leftmost Derivation