Compilers: Principles and Practice by Pearson

232 Compilers – Principles and Practice

We would like to have a look at the parse tree that we created in memory, for which we write a tree

traversal function:

void traverse_parse_tree(Node *root){

Node *np;

printf("[%s" ,root->w.S);

np = root->u.N;

while(np != NULL){

traverse_parse_tree(np);

np = np->v.N;

}

printf("]");

}

The following code segments illustrate modifications to the basic RDP code for generating an internal

parse tree. A typical function for a Non-Terminal symbol in the grammar looks like:

Node *pE(){

Node *np;

np = tree_root("E");

add_child(np,pT());

while(nextsymbol() == ’+’) {

add_child(np,pplus());

add_child(np,pT());