Struct MobSpawnPlacementCheckEvent 

pub struct MobSpawnPlacementCheckEvent<'a> {
    pub dimension: &'a str,
    pub kind: &'a str,
    pub reason: SpawnReason,
    pub pos: BlockPos,
    pub default_result: bool,
    pub level: LevelRef,
    pub spawner: Option<Spawner>,
    pub result: &'a mut SpawnCheck,
}

What Hooks::mob_spawn_placement_check is told. Each field is that hook’s argument of the same name, described in the hook’s doc.

Fields

dimension: &'a str

kind: &'a str

reason: SpawnReason

pos: BlockPos

default_result: bool

level: LevelRef

spawner: Option<Spawner>

result: &'a mut SpawnCheck