protected function convertOperation($expr1, $operator, $expr2)
	{
		$expr1 = $this->convert($expr1);
		$expr2 = $this->convert($expr2);

		// Prevent two consecutive minus signs to be interpreted as a post-decrement operator
		if ($operator === '-' && $expr2[0] === '-')
		{
			$operator .= ' ';
		}

		return $expr1 . $operator . $expr2;
	}
protected function convertOperation($expr1, $operator, $expr2)
	{
		$expr1 = $this->convert($expr1);
		$expr2 = $this->convert($expr2);

		// Prevent two consecutive minus signs to be interpreted as a post-decrement operator
		if ($operator === '-' && $expr2[0] === '-')
		{
			$operator .= ' ';
		}

		return $expr1 . $operator . $expr2;
	}
protected function convertOperation ( $ expr1 , $ operator , $ expr2 ) { $ expr1 = $ this -> convert ( $ expr1 ) ; $ expr2 = $ this -> convert ( $ expr2 ) ; // Prevent two consecutive minus signs to be interpreted as a post-decrement operator if ( $ operator === '-' && $ expr2 [ 0 ] === '-' ) { $ operator .= ' ' ; } return $ expr1 . $ operator . $ expr2 ; }
Convert an operation

@param  string $expr1
@param  string $operator
@param  string $expr2
@return string
Convert an operation