fix: number tracing (EnzymeAD#849)

Author: avik-pal

src/Tracing.jl

@@ -55,7 +55,7 @@ Base.@nospecializeinfer function traced_type_inner(
     @nospecialize(track_numbers::Type),
     @nospecialize(sharding)
 )
-    if Mode == ArrayToConcrete && T <: track_numbers
+    if mode == ArrayToConcrete && T <: track_numbers
         return ConcretePJRTNumber{
             T,Sharding.ndevices(sharding),Sharding.shard_type(typeof(sharding), 0)
         }

test/tracing.jl

@@ -15,6 +15,17 @@ struct Wrapper{A,B}
     b::B
 end
 
+struct Descent{T}
+    eta::T
+end
+
+struct RMSProp{Teta,Trho,Teps,C<:Bool}
+    eta::Teta
+    rho::Trho
+    epsilon::Teps
+    centred::C
+end
+
 @testset "Tracing" begin
     @testset "trace_type" begin
         @testset "mode = ConcreteToTraced" begin
@@ -242,4 +253,17 @@ end
         st_traced = Reactant.to_rarray(st; track_numbers=Number)
         @test st_traced.training isa Val{true}
     end
+
+    @testset "to_rarray(::AbstractRule)" begin
+        opt = Descent(0.1)
+        opt_traced = Reactant.to_rarray(opt; track_numbers=AbstractFloat)
+        @test opt_traced.eta isa ConcreteRNumber{Float64}
+
+        opt = RMSProp(0.1, 0.9, 1e-8, true)
+        opt_traced = Reactant.to_rarray(opt; track_numbers=AbstractFloat)
+        @test opt_traced.eta isa ConcreteRNumber{Float64}
+        @test opt_traced.rho isa ConcreteRNumber{Float64}
+        @test opt_traced.epsilon isa ConcreteRNumber{Float64}
+        @test opt_traced.centred isa Bool
+    end
 end