atk4\data\tests\Structure::_render_field PHP Method

    public function _render_field()
    {
        $ret = [];
        if (!$this->args['field']) {
            throw new Exception(['No fields defined for table']);
        }
        foreach ($this->args['field'] as $field => $options) {
            if ($options instanceof Expression) {
                $ret[] = $this->_escape($field) . ' ' . $this->_consume($options);
                continue;
            }
            $type = strtolower(isset($options['type']) ? $options['type'] : 'varchar');
            $type = preg_replace('/[^a-z0-9]+/', '', $type);
            $len = isset($options['len']) ? $options['len'] : ($type === 'varchar' ? 255 : null);
            $ret[] = $this->_escape($field) . ' ' . $type . ($len ? '(' . $len . ')' : '');
        }
        return implode(',', $ret);
    }