/**
* Node factory, creating an appropriate Node from a Token.
*
* Based on the provided Token, returns a TerminalNode if the
* token type is PosInt, Integer, RealNumber, Identifier or Constant
* otherwise returns null.
*
* @param Token $token Provided token
* @retval Node|null
*/
public static function factory(Token $token)
{
switch ($token->getType()) {
case TokenType::PosInt:
case TokenType::Integer:
$x = intval($token->getValue());
return new NumberNode($x);
case TokenType::RealNumber:
$x = floatval($token->getValue());
return new NumberNode($x);
case TokenType::Identifier:
return new VariableNode($token->getValue());
case TokenType::Constant:
return new ConstantNode($token->getValue());
case TokenType::FunctionName:
return new FunctionNode($token->getValue(), null);
case TokenType::OpenParenthesis:
return new SubExpressionNode($token->getValue());
case TokenType::AdditionOperator:
case TokenType::SubtractionOperator:
case TokenType::MultiplicationOperator:
case TokenType::DivisionOperator:
case TokenType::ExponentiationOperator:
return new ExpressionNode(null, $token->getValue(), null);
default:
// echo "Node factory returning null on $token\n";
return null;
}
}
public function testCanPrintToken()
{
$name = '+';
$type = TokenType::AdditionOperator;
$token = new Token($name, $type);
$string = $token->__toString();
$this->assertEquals($string, "Token: [{$name}, {$type}]");
}
private function assertTokenEquals($value, $type, Token $token)
{
$this->assertEquals($value, $token->getValue());
$this->assertEquals($type, $token->getType());
}
/**
* Insert multiplication tokens where needed (taking care of implicit mulitplication).
*
* @param array $tokens Input list of tokens (Token[])
* @retval Token[]
*/
protected function parseImplicitMultiplication(array $tokens)
{
$result = [];
$lastToken = null;
foreach ($tokens as $token) {
if (Token::canFactorsInImplicitMultiplication($lastToken, $token)) {
$result[] = new Token('*', TokenType::MultiplicationOperator);
}
$lastToken = $token;
$result[] = $token;
}
return $result;
}
