Question

Which one of the following is true at any valid state in shift-reduce parsing?

(a) At the bottom we find the prefixes

(b) None of the mentioned

(c) Stack contains only viable prefixes

(d) Stack consists of viable prefixes

I got this question at a job interview.

Enquiry is from Predictive Top-Down Parsing topic in division Topdown Parsing of Compiler

Answer 1

Right answer is (c) Stack contains only viable prefixes

To elaborate: The prefixes on the stack of a shift-reduce parser are called viable prefixes.