Predictive_Parser::Predictive_Parser(CFG *grammar) {
//init vars
this->grammar = grammar;
first = new map<string, set<string>*> ();
follow = new map<string, set<string>*> ();
subset_first = new map<pair<string,int>,set<string>*>();
parse_table = new Parse_Table_Entry*[grammar->get_nonterminals()->size()];
//size = size of terminals + 1 (input end marker)
for (unsigned int i = 0; i < grammar->get_nonterminals()->size(); ++i)
parse_table[i] = new Parse_Table_Entry[grammar->get_terminals()->size() + 1];
//calculate first
set<string>* nonterminals = grammar->get_nonterminals();
for (set<string>::iterator it = nonterminals->begin(); it
!= nonterminals->end(); ++it) {
calc_first(*it);
}
//calculate follow
calc_follow();
//generate parsing table
generate_table();
}
void LL_construct()
{
try
{
prepare_nonterminals();
calc_first();
print_first();
calc_follow();
print_follow();
parse_table_generate();
print_parse_table();
}
catch (ConstructException &e)
{
puts(e.message);
puts("Syntax analyzer construct failed.");
}
}
