void Consequent::load(const std::string& consequent, const Engine* engine) {
unload();
setText(consequent);
if (Op::trim(consequent).empty()) {
throw Exception("[syntax error] consequent is empty", FL_AT);
}
/**
Extracts the list of propositions from the consequent
The rules are:
1) After a variable comes 'is' or '=',
2) After 'is' comes a hedge or a term
3) After a hedge comes a hedge or a term
4) After a term comes operators 'and' or 'with'
5) After operator 'and' comes a variable
6) After operator 'with' comes a float
*/
enum FSM {
S_VARIABLE = 1, S_IS = 2, S_HEDGE = 4, S_TERM = 8,
S_AND = 16, S_WITH = 32
};
int state = S_VARIABLE;
Proposition* proposition = fl::null;
std::stringstream tokenizer(consequent);
std::string token;
try {
while (tokenizer >> token) {
if (state bitand S_VARIABLE) {
if (engine->hasOutputVariable(token)) {
proposition = new Proposition;
proposition->variable = engine->getOutputVariable(token);
conclusions().push_back(proposition);
state = S_IS;
continue;
}
}
if (state bitand S_IS) {
if (token == Rule::isKeyword()) {
state = S_HEDGE bitor S_TERM;
continue;
}
}
if (state bitand S_HEDGE) {
HedgeFactory* factory = FactoryManager::instance()->hedge();
if (factory->hasConstructor(token)) {
Hedge* hedge = factory->constructObject(token);
proposition->hedges.push_back(hedge);
state = S_HEDGE bitor S_TERM;
continue;
}
}
if (state bitand S_TERM) {
if (proposition->variable->hasTerm(token)) {
proposition->term = proposition->variable->getTerm(token);
state = S_AND bitor S_WITH;
continue;
}
}
if (state bitand S_AND) {
if (token == Rule::andKeyword()) {
state = S_VARIABLE;
continue;
}
}
//if reached this point, there was an error:
if (state bitand S_VARIABLE) {
std::ostringstream ex;
ex << "[syntax error] consequent expected output variable, but found <" << token << ">";
throw Exception(ex.str(), FL_AT);
}
if (state bitand S_IS) {
std::ostringstream ex;
ex << "[syntax error] consequent expected keyword <" << Rule::isKeyword() << ">, "
"but found <" << token << ">";
throw Exception(ex.str(), FL_AT);
}
if ((state bitand S_HEDGE) or (state bitand S_TERM)) {
std::ostringstream ex;
ex << "[syntax error] consequent expected hedge or term, but found <" << token << ">";
throw Exception(ex.str(), FL_AT);
}
if ((state bitand S_AND) or (state bitand S_WITH)) {
std::ostringstream ex;
ex << "[syntax error] consequent expected operator <" << Rule::andKeyword() << "> "
<< "or keyword <" << Rule::withKeyword() << ">, "
<< "but found <" << token << ">";
throw Exception(ex.str(), FL_AT);
}
std::ostringstream ex;
ex << "[syntax error] unexpected token <" << token << "> in consequent";
throw Exception(ex.str(), FL_AT);
}
if (not ((state bitand S_AND) or (state bitand S_WITH))) { //only acceptable final state
if (state bitand S_VARIABLE) {
std::ostringstream ex;
ex << "[syntax error] consequent expected output variable after <" << token << ">";
throw Exception(ex.str(), FL_AT);
}
if (state bitand S_IS) {
std::ostringstream ex;
ex << "[syntax error] consequent expected keyword <" << Rule::isKeyword() << "> "
"after <" << token << ">";
throw Exception(ex.str(), FL_AT);
}
if ((state bitand S_HEDGE) or (state bitand S_TERM)) {
std::ostringstream ex;
ex << "[syntax error] consequent expected hedge or term after <" << token << ">";
throw Exception(ex.str(), FL_AT);
}
}
} catch (...) {
unload();
throw;
}
}
void Antecedent::load(const std::string& antecedent, fl::Rule* rule, const Engine* engine) {
FL_DBG("Antecedent: " << antecedent);
unload();
this->_text = antecedent;
if (fl::Op::trim(antecedent).empty()) {
throw fl::Exception("[syntax error] antecedent is empty", FL_AT);
}
/*
Builds an proposition tree from the antecedent of a fuzzy rule.
The rules are:
1) After a variable comes 'is',
2) After 'is' comes a hedge or a term
3) After a hedge comes a hedge or a term
4) After a term comes a variable or an operator
*/
Function function;
std::string postfix = function.toPostfix(antecedent);
FL_DBG("Postfix: " << postfix);
std::stringstream tokenizer(postfix);
std::string token;
enum FSM {
S_VARIABLE = 1, S_IS = 2, S_HEDGE = 4, S_TERM = 8, S_AND_OR = 16
};
int state = S_VARIABLE;
std::stack<Expression*> expressionStack;
Proposition* proposition = fl::null;
try {
while (tokenizer >> token) {
if (state bitand S_VARIABLE) {
Variable* variable = fl::null;
if (engine->hasInputVariable(token)) variable = engine->getInputVariable(token);
else if (engine->hasOutputVariable(token)) variable = engine->getOutputVariable(token);
if (variable) {
proposition = new Proposition;
proposition->variable = variable;
expressionStack.push(proposition);
state = S_IS;
FL_DBG("Token <" << token << "> is variable");
continue;
}
}
if (state bitand S_IS) {
if (token == Rule::isKeyword()) {
state = S_HEDGE bitor S_TERM;
FL_DBG("Token <" << token << "> is keyword");
continue;
}
}
if (state bitand S_HEDGE) {
Hedge* hedge = rule->getHedge(token);
if (not hedge) {
HedgeFactory* factory = FactoryManager::instance()->hedge();
if (factory->hasConstructor(token)) {
hedge = factory->constructObject(token);
rule->addHedge(hedge);
}
}
if (hedge) {
proposition->hedges.push_back(hedge);
if (dynamic_cast<Any*> (hedge)) {
state = S_VARIABLE bitor S_AND_OR;
} else {
state = S_HEDGE bitor S_TERM;
}
FL_DBG("Token <" << token << "> is hedge");
continue;
}
}
if (state bitand S_TERM) {
if (proposition->variable->hasTerm(token)) {
proposition->term = proposition->variable->getTerm(token);
state = S_VARIABLE bitor S_AND_OR;
FL_DBG("Token <" << token << "> is term");
continue;
}
}
if (state bitand S_AND_OR) {
if (token == Rule::andKeyword() or token == Rule::orKeyword()) {
if (expressionStack.size() < 2) {
std::ostringstream ex;
ex << "[syntax error] logical operator <" << token << "> expects two operands,"
<< "but found <" << expressionStack.size() << "> in antecedent";
throw fl::Exception(ex.str(), FL_AT);
}
Operator* fuzzyOperator = new Operator;
fuzzyOperator->name = token;
fuzzyOperator->right = expressionStack.top();
expressionStack.pop();
fuzzyOperator->left = expressionStack.top();
expressionStack.pop();
expressionStack.push(fuzzyOperator);
state = S_VARIABLE bitor S_AND_OR;
FL_DBG("Subtree: " << fuzzyOperator->toString() <<
"(" << fuzzyOperator->left->toString() << ") " <<
"(" << fuzzyOperator->right->toString() << ")");
continue;
}
}
//If reached this point, there was an error
if ((state bitand S_VARIABLE) or (state bitand S_AND_OR)) {
std::ostringstream ex;
ex << "[syntax error] antecedent expected variable or logical operator, but found <" << token << ">";
throw fl::Exception(ex.str(), FL_AT);
}
if (state bitand S_IS) {
std::ostringstream ex;
ex << "[syntax error] antecedent expected keyword <" << Rule::isKeyword() << ">, but found <" << token << ">";
throw fl::Exception(ex.str(), FL_AT);
}
if ((state bitand S_HEDGE) or (state bitand S_TERM)) {
std::ostringstream ex;
ex << "[syntax error] antecedent expected hedge or term, but found <" << token << ">";
throw fl::Exception(ex.str(), FL_AT);
}
std::ostringstream ex;
ex << "[syntax error] unexpected token <" << token << "> in antecedent";
throw fl::Exception(ex.str(), FL_AT);
}
if (not ((state bitand S_VARIABLE) or (state bitand S_AND_OR))) { //only acceptable final state
if (state bitand S_IS) {
std::ostringstream ex;
ex << "[syntax error] antecedent expected keyword <" << Rule::isKeyword() << "> after <" << token << ">";
throw fl::Exception(ex.str(), FL_AT);
}
if ((state bitand S_HEDGE) or (state bitand S_TERM)) {
std::ostringstream ex;
ex << "[syntax error] antecedent expected hedge or term after <" << token << ">";
throw fl::Exception(ex.str(), FL_AT);
}
}
if (expressionStack.size() != 1) {
std::vector<std::string> errors;
while (expressionStack.size() > 1) {
Expression* expression = expressionStack.top();
expressionStack.pop();
errors.push_back(expression->toString());
delete expression;
}
std::ostringstream ex;
ex << "[syntax error] unable to parse the following expressions in antecedent <"
<< Op::join(errors, " ") << ">";
throw fl::Exception(ex.str(), FL_AT);
}
} catch (...) {
for (std::size_t i = 0; i < expressionStack.size(); ++i) {
delete expressionStack.top();
expressionStack.pop();
}
throw;
}
this->_expression = expressionStack.top();
}