feat: support serialization of clocks

src/clock.jl

@@ -2,7 +2,7 @@ module Clocks
 
 export TimeDomain
 
-using Expronicon.ADT: @adt, @match
+using Expronicon.ADT: variant_type, @adt, @match
 
 @adt TimeDomain begin
     Continuous
@@ -15,6 +15,16 @@ end
 
 Base.Broadcast.broadcastable(d::TimeDomain) = Ref(d)
 
+const DiscriminatorType = typeof(variant_type(Continuous))
+
+function Base.write(io::IO, x::DiscriminatorType)
+    write(io, Base.reinterpret(UInt32, x))
+end
+
+function Base.read(io::IO, ::Type{DiscriminatorType})
+    Base.reinterpret(DiscriminatorType, read(io, UInt32))
+end
+
 end
 
 using .Clocks

test/runtests.jl

@@ -60,6 +60,9 @@ end
         @time @safetestset "Problem building tests" begin
             include("problem_building_test.jl")
         end
+        @time @safetestset "Serialization tests" begin
+            include("serialization_tests.jl")
+        end
     end
 
     if !is_APPVEYOR &&

test/serialization_tests.jl

@@ -0,0 +1,18 @@
+using SciMLBase
+using Serialization
+using Test
+
+for clock in [
+        SciMLBase.Clock(0.5),
+        SciMLBase.Clock(0.5; phase = 0.1),
+        SciMLBase.SolverStepClock,
+        SciMLBase.Continuous,
+    ]
+    serialize("_tmp.jls", clock)
+    newclock = deserialize("_tmp.jls")
+    @test newclock == clock
+end
+
+if isfile("_tmp.jls")
+    rm("_tmp.jls")
+end