Only extract numeric arrays (#5)

Uses `is_numeric_array` to filter out any non-numeric arrays.

Project.toml

@@ -1,7 +1,7 @@
 name = "LegolasFlux"
 uuid = "eb5f792d-d1b1-4535-bae3-d5649ec7daa4"
 authors = ["Beacon Biosignals, Inc."]
-version = "0.1.1"
+version = "0.1.2"
 
 [deps]
 Arrow = "69666777-d1a9-59fb-9406-91d4454c9d45"

src/functors.jl

@@ -15,13 +15,17 @@ end
     fetch_weights(m) -> Vector{Array}
 
 Returns the weights of a model by using `Functors.children` to recurse
-through the model, keeping any arrays found. The `@functor` macro defines
+through the model, keeping any numeric arrays found. The `@functor` macro defines
 `Functors.children` automatically so that should be sufficient to support
 custom types.
 
-Note that this function does not copy the results, so that e.g. mutating `fetch_weights(m)[1]` modifies the model.
+Note that this function does not copy the results, so that e.g. mutating
+`fetch_weights(m)[1]` modifies the model.
 """
-fetch_weights(m) = filter(x -> x isa Array, fcollect2(m))
+fetch_weights(m) = filter(is_numeric_array, fcollect2(m))
+is_numeric_array(x) = false
+is_numeric_array(x::Array{<:Number}) = true
+is_numeric_array(x::Array) = all(x -> x isa Number || is_numeric_array(x), x)
 
 """
     load_weights!(m, xs)

test/runtests.jl

@@ -37,6 +37,24 @@ end
     rm("my_model.model.arrow")
 end
 
+struct MyArrayModel
+    dense_array::Array
+end
+Flux.@functor MyArrayModel
+
+@testset "Non-numeric arrays ignored" begin
+    m = MyArrayModel([Dense(1, 10), Dense(10, 10), Dense(10, 1)])
+    weights = fetch_weights(m)
+    @test length(weights) == 6
+
+    model_row = ModelRow(; weights=collect(weights))
+    write_model_row("my_model.model.arrow", model_row)
+
+    new_model_row = read_model_row("my_model.model.arrow")
+    new_weights = collect(new_model_row.weights)
+    @test new_weights == weights
+end
+
 @testset "Errors" begin
     my_model = make_my_model()
     w = test_weights()