Hey there

I’m getting “*LoadError: TypeError: in typeassert, expected Type, got a value of type EventType*” in the following code. I understand the error, but I do not understand why it occurs. Why does it expect a *Type* and not *EventType*? I believe I specified the correct type in the signature of register_s_arrival() and when I pass it to register_s_arrival() from simulate(), but that clearly doesn’t work.

Also: won’t there be a key-problem if more than one *V_ARRIVED_S**-event is enqueued? If so, do you have any good suggestions to avoid it?

I’m using Julia version 1.7.1 and I run it from my terminal. The following code should enable you to recreate the error:

```
using Random, Distributions, DataStructures
@enum EventType begin
V_ARRIVED_S1
V_ARRIVED_S2
end
struct Environment
hours_to_run::Float64
arrival_D_st1::Exponential
arrival_D_st2::Exponential
travel_time_st1st2_D::Exponential
travel_time_st2st1_D::Exponential
Environment() = new(420.0,
Exponential(10),
Exponential(10),
Exponential(10),
Exponential(10))
end
mutable struct State
vehicles::Vector{Int64}
State(v::Vector{Int64}) = new(v)
end
function register_s_arrival(station::Int64, s::State, env::Environment, q::PriorityQueue{EventType, Float64}, curr_t::Float64)
if s.vehicles[station] >= 1
s.vehicles[station] -= 1
if station == 1
ttime = curr_t + rand(env.travel_time_st1st2_D)
enqueue!(q, EventType::V_ARRIVED_S2, ttime)
else
ttime = curr_t + rand(env.travel_time_st2st1_D)
enqueue!(q, EventType::V_ARRIVED_S1, ttime)
end
return 0
else
return 1
end
end
function simulate(env::Environment, carsSt1::Int64, carsSt2::Int64)
t = 0
state = State([carsSt1, carsSt2])
events = PriorityQueue{EventType, Float64}()
dt1 = rand(env.arrival_D_st1)
dt2 = rand(env.arrival_D_st2)
while t <= env.hours_to_run
if dt1 < dt2
t = dt1
dt1 = rand(env.arrival_D_st1)
res = register_s_arrival(1, state, env, events, t)
else
t = dt2
dt2 = t + rand(env.arrival_D_st2)
res = register_s_arrival(2, state, env, events, t)
end
end
end
simulate(Environment(), 2, 2)
```

The stacktrace yields:

```
Stacktrace:
[1] register_s_arrival(station::Int64, s::State, env::Environment, q::PriorityQueue{EventType, Float64, Base.Order.ForwardOrdering}, curr_t::Float64)
@ Main mwe.jl:35
[2] simulate(env::Environment, carsSt1::Int64, carsSt2::Int64)
@ Main mwe.jl:59
[3] top-level scope
@ Main mwe.jl:64
in expression starting at mwe.jl:64
```

Please do not hesitate to ping for more information if I’ve left anything out or suggest formatting improvements, this is my first question on any programming forum.

I would appreciate any help, thank you in advance