/** equality ::= relational EQ relational equality ::= relational NEQ relational */
private Value equality() {
Value res = relational();
while (token.getType() == TokenType.EQ || token.getType() == TokenType.NEQ) {
if (token.getType() == TokenType.EQ) {
res.setBooleanValue(res.getValue() == relational().getValue());
} else if (token.getType() == TokenType.NEQ) {
res.setBooleanValue(res.getValue() != relational().getValue());
}
}
return res;
}
/** logicalOr ::= logicalAnd OR logicalAnd */
private Value logicalOr() {
Value res = logicalAnd();
while (token.getType() == TokenType.OR) {
Value operand = logicalAnd();
res.setBooleanValue(res.getBooleanValue() || operand.getBooleanValue());
}
return res;
}
/** logicalAnd ::= equality AND equality */
private Value logicalAnd() {
Value res = equality();
while (token.getType() == TokenType.AND) {
Value operand = equality();
res.setBooleanValue(res.getBooleanValue() && operand.getBooleanValue());
}
return res;
}
/**
* relational ::= additive LT additive relational ::= additive GT additive relational ::= additive
* LTE additive relational ::= additive GTE additive
*/
private Value relational() {
Value res = additive();
while (token.getType() == TokenType.LT
|| token.getType() == TokenType.GT
|| token.getType() == TokenType.LTE
|| token.getType() == TokenType.GTE) {
if (token.getType() == TokenType.LT) {
res.setBooleanValue(res.getValue() < additive().getValue());
} else if (token.getType() == TokenType.GT) {
res.setBooleanValue(res.getValue() > additive().getValue());
} else if (token.getType() == TokenType.LTE) {
res.setBooleanValue(res.getValue() <= additive().getValue());
} else if (token.getType() == TokenType.GTE) {
res.setBooleanValue(res.getValue() >= additive().getValue());
}
}
return res;
}
/**
* unary ::= NUMBER unary ::= OPEN logicalOr CLOSE unary ::= VARIABLE unary ::= NOT unary unary
* ::= SUB unary unary ::= ADD unary
*/
private Value unary() {
final Value res;
nextToken();
if (token.getType() == TokenType.SUB) {
res = unary();
return res.setValue(-res.getValue());
} else if (token.getType() == TokenType.ADD) {
return unary();
} else if (token.getType() == TokenType.NOT) {
res = unary();
return res.setBooleanValue(!res.getBooleanValue());
} else if (token.getType() == TokenType.OPEN) {
res = logicalOr();
if (token.getType() != TokenType.CLOSE) {
throw expected(TokenType.CLOSE);
}
} else if (token.getType() == TokenType.NUMBER) {
res = token.getValue();
} else if (token.getType() == TokenType.VARIABLE) {
// resolve variable
res = variables.get(token.getStr());
if (res == null) {
throw new IllegalStateException("Unexpected variable name");
}
} else {
throw expected(
TokenType.SUB,
TokenType.ADD,
TokenType.NOT,
TokenType.OPEN,
TokenType.NUMBER,
TokenType.VARIABLE);
}
nextToken();
return res;
}
