Fire/Sql/Collection.php
public function _isValueIndexable($value)
    {
        return (
            is_string($value)
            || is_null($value)
            || is_bool($value)
            || is_integer($value)
        );
    }
public function _isValueIndexable($value)
    {
        return (
            is_string($value)
            || is_null($value)
            || is_bool($value)
            || is_integer($value)
        );
    }
public function _isValueIndexable ( $ value ) { return ( is_string ( $ value ) || is_null ( $ value ) || is_bool ( $ value ) || is_integer ( $ value ) ) ; }
Determines if a value is indexable.
@param mixed $value
@return boolean
Determines if a value is indexable .