ECS:system

Returns an existing System of a specific class or inheriting from it.

Usage

ecs:system(class)

Arguments

Name	Type	Description
class	string or system class	The system class to look for, as a string or as a reference.

Returns

Name	Type	Description
system	System	A system of the specified class (or inheriting from it).

If no matching system exists, this method returns nil.

If multiple systems match the requested class, any of them may be returned.

Examples

local MySystem = Class("MySystem", crystal.System);
local ecs = crystal.ECS:new();
local my_system = ecs:add_system("MySystem");
assert(my_system == ecs:system("MySystem"));