UNIT -2 B Top-Down Parsing Quiz

What is the main characteristic of top-down parsing?

• It starts from the leaves and builds the parse tree upward

• It starts from the root and constructs the parse tree downward

• It directly generates machine code

• It optimizes the intermediate code

Which type of grammar cannot be handled by top-down parsers?

• Ambiguous grammars

• Left-recursive grammars

• Context-free grammars

• Regular grammars

What is backtracking in the context of top-down parsing?

• Revisiting previously generated parse trees

• Reverting to earlier parse states to try alternative derivations

• Generating optimized machine code

• Constructing intermediate code

What is the disadvantage of backtracking in top-down parsing?

• It requires complex grammar rules

• It increases parsing speed

• It increases parsing time due to trial-and-error

• It only works for left-recursive grammars

Which of the following is an advantage of top-down parsing?

• Works with ambiguous grammars

• Easy to implement for simple grammars

• Handles left recursion directly

• Efficient for all types of grammars

What is recursive descent parsing?

• A type of bottom-up parsing

• A top-down parsing technique implemented using recursive procedures

• A parsing method that constructs the parse tree in reverse

• A parsing method optimized for ambiguous grammars

Recursive descent parsing is typically used for:

• Left-recursive grammars

• Ambiguous grammars

• LL(1) grammars

• Context-sensitive grammars

Why can't recursive descent parsers handle left-recursive grammars?

• Left recursion causes infinite recursion

• Left recursion requires backtracking

• Left recursion is not part of context-free grammars

• Left recursion violates LL(1) grammar rules

In recursive descent parsing, each non-terminal in the grammar is implemented as a:

• Function

• Loop

• DFA

• State machine

Which of the following is a key limitation of recursive descent parsing?

• It requires a parse table

• It cannot handle left recursion or ambiguous grammars

• It needs a symbol table for execution

• It only works with infinite lookahead