We invent predictive top-down (PTD) parsers for a subclass of these grammars, similar to recursive descent parsers for string languages. The focus of this paper lies on the grammar analysis that computes neighbor edges of nonterminals, in analogy to the first and follow symbols used in SLL(1...
Predictive parser It is a recursive-descent parser that needs no backtracking Suppose A -> A1 | A2 | ….| An If the non-terminal to be expanded next is ‘A’, then the choice of rule is made on the basis of the current input symbol ‘a’. Procedure Make a transition diagram( like...