Why can't a recursive-descent parser handle left recursion?

Question

Could someone please explain to me why recursive-descent parsers can't work with a grammar containing left recursion?

Answer 1

Hi There,

Recursive descent parsing is actually a technique. It cannot handle left-recursion because it is a top-down parsing technique, and top-down parsers cannot handle left recursion. This is because in left recursion, for a rule conforming to: A -> Aἄ | β, the starting symbol is repeated immediately after the arrow; making the derivation refer to itself infinitely times.

This usually implies a follow up question, how do you get rid of left recursion?

For this, use your alpha/beta rules.