具体场景 Concrete scenario

具体场景的参数声明支持基础类型、标量(scalar)类型、枚举(enum)类型，和 结构(struct)类型：

• 基础类型包含int、float、bool，和string类型.可以直接在等号后赋值.
• scalar类型包含speed、acceleration、length、time，和angle类型.赋值时需要在值后 加上OSC2.0支持的单位（见附录Scalar units）.
• enum类型包含side_left_right、distance_direction、distance_mode、 lane_change_side、 dynamics_shape，和 catalog.赋值时必须使用枚举列表内的值（见附录Enum list） .
• struct类型包含odr_point、xyz_point、position_3d、road_point、orientation_3d和pose_3d等，可以使用 keep创建.此外，odr_point、xyz_point，和road_point分别可以使用map的成员函数 create_odr_point 、 create_xyz_point 和create_road_point 来创建（OSC2.0支持的struct类型详见附录Struct）.

• 给bool型赋值时必须使用'true'和'false'，如果使用'True'或'False'或拼写错误将使语句无效.

例1：基础类型

m_road_id: string = '0'
Ego_name: string = "Audi_A3_2009_black"
m_lateral: bool = true

例2：scalar类型

v: speed = 5mps
delay: time = 40s
distance: length = 30.0m
m_a: acceleration = 0.01mpss

例3：enum类型

m_side: side_left_right = right
m_direction: distance_direction = longitudinal

例4：struct类型，keep创建

my_odr: odr_point with:
    keep(it.road_id == 0)
    keep(it.lane_id == -1)
    keep(it.s == 3.0m)
    keep(it.t == 0.0m)

my_pos: position_3d with:
    keep(it.x == 1.0m)
    keep(it.y == 2.0m)
    keep(it.z == 3.0m)

my_xyz: xyz_point with:
    keep(it.position == my_pos)

my_road: road_point with:
    keep(it.road_id == '1')
    keep(it.s == 3.0m)
    keep(it.t == 0.0m)

my_orientation: orientation_3d with:
    keep(it.roll == 1.0rad)
    keep(it.pitch == 2.0rad)
    keep(it.yaw == 3.0rad)

my_pose: pose_3d with:
    keep(it.xyz_point == my_xyz)
    keep(it.orientation == m_orientation)

m_trajectory: trajectory with:
    keep(it.points == [my_pose1, my_pose2, my_pose3])
    keep(it.time_stamps == [0s, 5s, 20s] )

例5：struct类型，map创建

my_odr: odr_point = map.create_odr_point(road_id: m_road_id,lane_id:'-4',s: 5.0m, t: 0.0m) 
my_xyz: xyz_point = map.create_xyz_point(x: 2.5m, y: 10.0m ,z: 0.0m)
my_point: road_point = map.create_road_point(road_id: '1', s: 5.0m, t: 0.0m)