Extending Base.stack for DimArrays

src/array/methods.jl

@@ -529,6 +529,14 @@ $message on dimension $D.
 To fix for `AbstractDimArray`, pass new lookup values as `cat(As...; dims=$D(newlookupvals))` keyword or `dims=$D()` for empty `NoLookup`.
 """
 
+function check_stack_dims(iter)
+    comparedims(Bool, dims.(iter)...; order=true, val=true, msg=Dimensions.Warn(" Can't `stack` AbstractDimArray, applying to `parent` object."))
+    iter
+end
+Base.stack(iter::AbstractArray{<:AbstractDimArray}; dims=:) = Base._stack(dims, check_stack_dims(iter))
+Base.stack(f, iter::AbstractArray{<:AbstractDimArray}; dims=:) = Base._stack(dims, f(x) for x in check_stack_dims(iter))
+Base.stack(f, xs::AbstractArray{<:AbstractDimArray}, yzs...; dims=:) = _stack(dims, f(xy...) |> check_stack_dims for xy in zip(xs, yzs...))
+
 function Base.inv(A::AbstractDimArray{T,2}) where T
     newdata = inv(parent(A))
     newdims = reverse(dims(A))

test/methods.jl

@@ -802,6 +802,35 @@ end
     end
 end
 
+@testset "Base.stack" begin
+    a = [1 2 3; 4 5 6]
+    da = DimArray(a, (X(4.0:5.0), Y(6.0:8.0)))
+    b = [7 8 9; 10 11 12]
+    ca = DimArray(b, (X(4.0:5.0), Y(6.0:8.0)))
+    db = DimArray(b, (X(6.0:7.0), Y(6.0:8.0)))
+
+    x = DimArray([da, db], (Z(4.0:5.0)))
+    @test_warn "Lookup values" stack(x)
+
+    x = DimArray(fill(da, 2, 2), (Dim{:a}(4.0:5.0), Dim{:b}(6.0:7.0)))
+    sx = stack(x)
+    @test sx isa AbstractDimArray
+    @test dims(sx) == (dims(first(x))..., dims(x)...)
+
+    x = DimArray([da, ca], (Dim{:a}(1:2),))
+    sx = stack(x; dims=1)
+    @test sx == stack([parent(da), parent(ca)], dims=1)
+    @test sx isa AbstractDimArray
+    @test dims(sx) == (dims(x)..., dims(first(x))...)
+
+    for d = 1:3
+        x = DimArray([da, ca], (AnonDim(),))
+        dc = stack(x, dims=d)
+        @test dims(dc, d) isa AnonDim
+        @test parent(dc) == stack([da, db], dims=d)
+    end
+end
+
 @testset "unique" begin
     a = [1 1 6; 1 1 6]
     xs = (X, X(), :X)