8.4. Example

Let's build the top-down parsing table for the following grammar, with start nonterminal L.

1. L ε
2. L N
3. N E R
4. R ε
5. R , N
6. E n

The FIRST and FOLLOW sets are easy to compute, using the algorithms from the two preceding sections.

X L N R E
FIRST(X) {n, ε} {n} {,, ε} {n}
FOLLOW(X) {$} {$} {$} {,, $}

The parsing table is as follows.

Table D
n , $
L 2 1
N 3
R 5 4
E 6