Merge pull request #177 from pebeto/dev

Adding flat_params function

Author: ablaom

src/parameter_inspection.jl

@@ -30,6 +30,33 @@ function params(m, ::Val{true})
     return NamedTuple{fields}(Tuple([params(getfield(m, field)) for field in fields]))
 end
 
+isamodel(::Any) = false
+isamodel(::Model) = true
 
+"""
+    flat_params(m::Model)
+
+Recursively convert any object subtyping `Model` into a named tuple, keyed on
+the property names of `m`. The named tuple is possibly nested because
+`flat_params` is recursively applied to the property values, which themselves
+might subtype `Model`.
+
+For most `Model` objects, properties are synonymous with fields, but this is
+not a hard requirement.
 
+    julia> flat_params(EnsembleModel(atom=ConstantClassifier()))
+    (atom = (target_type = Bool,),
+     weights = Float64[],
+     bagging_fraction = 0.8,
+     rng_seed = 0,
+     n = 100,
+     parallel = true,)
 
+"""
+flat_params(m; prefix="") = flat_params(m, Val(isamodel(m)); prefix=prefix)
+flat_params(m, ::Val{false}; prefix="") = NamedTuple{(Symbol(prefix),), Tuple{Any}}((m,))
+function flat_params(m, ::Val{true}; prefix="")
+    fields = propertynames(m)
+    prefix = prefix == "" ? "" : prefix * "__"
+    merge([flat_params(getproperty(m, field); prefix="$(prefix)$(field)") for field in fields]...)
+end

test/parameter_inspection.jl

@@ -12,12 +12,13 @@ end
 
 MLJModelInterface.istransparent(::Transparent) = true
 
-struct Dummy <:MLJType
+struct Dummy <: MLJType
     t::Transparent
     o::Opaque
     n::Integer
 end
 
+
 @testset "params method" begin
 
     t= Transparent(6, Opaque(5))
@@ -32,4 +33,31 @@ end
         n = 42
     )
 end
+
+struct ChildModel <: Model
+    x::Int
+    y::String
+end
+
+struct ParentModel <: Model
+    x::Int
+    y::String
+    first_child::ChildModel
+    second_child::ChildModel
+end
+
+@testset "flat_params method" begin
+
+    m = ParentModel(1, "parent", ChildModel(2, "child1"),
+        ChildModel(3, "child2"))
+
+    @test MLJModelInterface.flat_params(m) == (
+        x = 1,
+        y = "parent",
+        first_child__x = 2,
+        first_child__y = "child1",
+        second_child__x = 3,
+        second_child__y = "child2"
+    )
+end
 true