ControlSystems compat part 2: Promote. Closes #87

Author: jonniedie

src/broadcasting.jl

@@ -104,7 +104,7 @@ function fill_flat(Ax1, Ax2, N1, N2)
         N = N1
         ax1, ax2 = Ax1, Ax2
     end
-    Ax = promote.(getaxes(ax1), getaxes(ax2)) |> typeof
+    Ax = Base.promote_typeof(getaxes(ax1), getaxes(ax2))
     return Ax, N
 end
 fill_flat(Ax::Type{<:VarAxes}, N) = fill_flat(getaxes(Ax), N) |> typeof

src/componentarray.jl

@@ -273,13 +273,13 @@ julia> getaxes(ca)
 @inline getaxes(x::AdjOrTrans{T, <:ComponentVector}) where T = (FlatAxis(), getaxes(x.parent)[1])
 @inline getaxes(x::AdjOrTrans{T, <:ComponentMatrix}) where T = reverse(getaxes(x.parent))
 
-@inline getaxes(::Type{<:ComponentArray{T,N,A,<:Axes}}) where {T,N,A,Axes} = map(x->x(), (Axes.types...,))
-@inline getaxes(::Type{<:AdjOrTrans{T,<:CA}}) where {T,CA<:ComponentVector} = (FlatAxis(), getaxes(CA)[1]) |> typeof
-@inline getaxes(::Type{<:AdjOrTrans{T,<:CA}}) where {T,CA<:ComponentMatrix} = reverse(getaxes(CA)) |> typeof
+@inline getaxes(::Type{<:ComponentArray{T,N,A,Axes}}) where {T,N,A,Axes} = map(x->x(), (Axes.types...,))
+@inline getaxes(::Type{<:AdjOrTrans{T,CA}}) where {T,CA<:ComponentVector} = (FlatAxis(), getaxes(CA)[1]) |> typeof
+@inline getaxes(::Type{<:AdjOrTrans{T,CA}}) where {T,CA<:ComponentMatrix} = reverse(getaxes(CA)) |> typeof
 
 ## Field access through these functions to reserve dot-getting for keys
 @inline getaxes(x::VarAxes) = getaxes(typeof(x))
-@inline getaxes(Ax::Type{<:Axes}) where {Axes<:VarAxes} = map(x->x(), (Ax.types...,))
+@inline getaxes(Ax::Type{Axes}) where {Axes<:VarAxes} = map(x->x(), (Ax.types...,))
 
 getaxes(x) = ()
 

src/similar_convert_copy.jl

@@ -49,8 +49,15 @@ end
 Base.deepcopy(x::ComponentArray) = ComponentArray(deepcopy(getdata(x)), getaxes(x))
 
 
-Base.convert(::Type{CA}, A::AbstractArray) where CA<:ComponentArray = ComponentArray(A, getaxes(CA))
-Base.convert(::Type{CA}, x::ComponentArray) where CA<:ComponentArray = ComponentArray(getdata(x), getaxes(CA))
+function Base.convert(::Type{ComponentArray{T,N,AA,Ax}}, A::AbstractArray) where {T,N,AA,Ax}
+    return ComponentArray{Ax}(A)
+end
+function Base.convert(::Type{ComponentArray{T,N,A,Ax1}}, x::ComponentArray{T,N,A,Ax2}) where {T,N,A,Ax1,Ax2}
+    return x
+end
+function Base.convert(::Type{ComponentArray{T1,N,A1,Ax1}}, x::ComponentArray{T2,N,A2,Ax2}) where {T1,T2,N,A1,A2,Ax1,Ax2}
+    return T1.(x)
+end
 Base.convert(::Type{<:Array}, x::ComponentArray) = convert(Array, getdata(x))
 
 
@@ -78,20 +85,14 @@ Base.NamedTuple(x::ComponentVector) = _namedtuple(x)
 
 
 ## AbstractAxis conversion and promotion
-# Base.convert(TypeAx::Type{<:Ax1}, ::Ax2) where {Ax1<:AbstractAxis,Ax2<:AbstractAxis} = promote_type(TypeAx,Ax2)()
-# Base.convert(::Type{Ax1}, ax::Ax2) where {Ax1<:AbstractAxis,Ax2<:AbstractAxis} = Ax1()
-
-# Could not figure out promote_rule for these.
-Base.promote(ax::AbstractAxis, ::NullAxis) = ax
-Base.promote(ax::AbstractAxis, ::FlatAxis) = ax
-Base.promote(::NullAxis, ax::AbstractAxis) = ax
-Base.promote(::FlatAxis, ax::AbstractAxis) = ax
-Base.promote(::FlatAxis, ::NullAxis) = FlatAxis()
-Base.promote(::NullAxis, ::FlatAxis) = FlatAxis()
-Base.promote(::FlatAxis, ::FlatAxis) = FlatAxis()
-Base.promote(::NullAxis, ::NullAxis) = NullAxis()
-Base.promote(ax::Ax, ::Ax) where {Ax<:AbstractAxis} = ax
-function Base.promote(ax1::AbstractAxis, ax2::AbstractAxis)
-    @warn "Tried to promote dissimilar axes of types $(typeof(ax1)) and $(typeof(ax2)). Falling back to FlatAxis."
-    return FlatAxis()
-end
+Base.convert(::Type{Ax}, ::AbstractAxis) where {Ax<:AbstractAxis} = Ax()
+Base.convert(::Type{Ax}, ax::AbstractAxis) where {Ax<:VarAxes} = convert.(typeof.(getaxes(Ax)), (ax,))
+
+Base.promote_rule(AA::Type{<:Axis}, ::Type{<:NullAxis}) = AA
+Base.promote_rule(AA::Type{<:Axis}, ::Type{<:FlatAxis}) = AA
+Base.promote_rule(FA::Type{FlatAxis}, ::Type{NullAxis}) = FA
+Base.promote_rule(FA::Type{FlatAxis}, ::Type{FlatAxis}) = FA
+Base.promote_rule(NA::Type{NullAxis}, ::Type{NullAxis}) = NA
+function Base.promote_rule(A1::Type{<:VarAxes}, A2::Type{<:VarAxes})
+    ax = first.(promote.(getaxes(A1), getaxes(A2))) |> typeof
+end

test/runtests.jl

@@ -206,6 +206,17 @@ end
         ca = ComponentVector(a=1, b=2, c=3)
         @test_throws BoundsError ca[:a, :b]
     end
+
+    # Issue # 87: Conversion/promotion
+    let
+        ax1 = Axis((; x1=1))
+        ax2 = Axis((; x2=1))
+        A1 = ComponentMatrix(zeros(1, 1), ax1, ax1)
+        A2 = ComponentMatrix(zeros(1, 1), ax2, ax2)
+        A = [A for A in [A1, A2]]
+        @test A[1] == A1
+        @test A[2] == A2
+    end
 end
 
 @testset "Set" begin