. Predictive parser can be implemented by maintaining an external stack
 |
Parse table is a
two dimensional array
M[X,a] where "X" is a
non terminal and "a" is
a terminal of the grammar |
It is possible to build a non recursive predictive parser maintaining a stack explicitly, rather than implicitly via recursive calls. A table-driven predictive parser has an input buffer, a stack, a parsing table, and an output stream. The input buffer contains the string to be parsed, followed by $, a symbol used as a right end marker to indicate the end of the input string. The stack contains a sequence of grammar symbols with a $ on the bottom, indicating the bottom of the stack. Initially the stack contains the start symbol of the grammar on top of $. The parsing table is a two-dimensional array M [X,a] , where X is a non-terminal, and a is a terminal or the symbol $ . The key problem during predictive parsing is that of determining the production to be applied for a non-terminal. The non-recursive parser looks up the production to be applied in the parsing table. We shall see how a predictive parser works in the subsequent slides.
