static void generateRandomSentences(const map<string, Definition>& grammar,
int numSentencesNeeded) {
for (int i = 0; i < numSentencesNeeded; ++i) {
Definition defin = grammar.at("<start>");
Production prod = defin.getRandomProduction();
expendProduction(prod, grammar);
cout << endl;
}
}
static void expandOn(const map<string, Definition>& grammar, int aNonTerminalPos, vector<string>& aResult)
{
if(aNonTerminalPos == -1)
{
// Base case //
return;
}
else
{
// Recursive case //
auto iterator = grammar.find(aResult[aNonTerminalPos]);
// If non-terminal is not defined then display error msg and exit.
if(iterator == grammar.end()) {
cout << "Could not find \"" << aResult[aNonTerminalPos] << "\" in the grammar file." << endl;
exit (EXIT_FAILURE);
}
Definition myDefinition = iterator->second;
Production myRandProduction = myDefinition.getRandomProduction();
// Get iterator 1 passed pos to insert.
auto resultIterator = aResult.begin()+aNonTerminalPos+1;
aResult.insert(resultIterator, myRandProduction.begin(), myRandProduction.end());
// Get new valid iterator and delete expanded non-terminal.
resultIterator = aResult.begin()+aNonTerminalPos;
aResult.erase(resultIterator);
// Iterate through result vector to expand on non-terminals.
// Start from previously expanded position.
int newNonTerminalPos = -1;
int pos = aNonTerminalPos;
for(auto start = aResult.begin()+aNonTerminalPos; start != aResult.end(); start++)
{
// Check if non-terminal.
if( (*start)[0] == '<')
{
newNonTerminalPos = pos;
break;
}
pos++;
}
// Recurse.
expandOn(grammar, newNonTerminalPos, aResult);
}
}
static void expendProduction(Production& production, const map<string, Definition>& grammar) {
for (auto iter = production.begin(); iter < production.end(); ++iter) {
string str = *iter;
if (str.find('<') == std::string::npos) {
cout << str << " ";
} else {
Definition def = grammar.at(str);
Production prod = def.getRandomProduction();
expendProduction(prod, grammar);
}
}
}