implement 1-arg cat/hcat/vcat (#115)

* implement 1-arg cat/hcat/vcat

* fix tests

* simplify hcat

Author: mzgubic

src/functions.jl

@@ -173,6 +173,21 @@ for (T, S) in [ (:KeyedArray, :KeyedArray),
     end
 
 end
+# single argument
+Base.vcat(A::KeyedArray) = A
+function Base.hcat(A::KeyedArray)
+    data = hcat(keyless(A))
+    akeys = map(copy, (keys_or_axes(A, 1), keys_or_axes(A, 2)))
+    KeyedArray(data, akeys)
+end
+function Base.cat(A::KeyedArray; dims)
+    new_names = NamedDims.expand_dimnames(dimnames(A), dims)
+    numerical_dims = NamedDims.dim(new_names, dims)
+    data = cat(keyless(A); dims=dims)
+    new_keys = ntuple(d -> keys_or_axes(A, d), ndims(data))
+    KeyedArray(data, map(copy, new_keys)) # , copy(A.meta))
+end
+
 val_strip(dims::Val{d}) where {d} = d
 val_strip(dims) = dims
 key_vcat(a::AbstractVector, b::AbstractVector) = vcat(a,b)

test/_functions.jl

@@ -209,6 +209,20 @@ end
     @test_throws ArgumentError axiskeys(reduce(hcat, twomats'))
     @test_throws ArgumentError axiskeys(reduce(vcat, twomats))
 
+    # single argument
+    @test dimnames(vcat(V)) == dimnames(cat(V; dims=1)) == (:r,)
+    @test axiskeys(vcat(V)) == axiskeys(cat(V; dims=1)) == (['a', 'b', 'c'],)
+    @test dimnames(hcat(V)) == dimnames(cat(V; dims=2)) == (:r, :_)
+    @test axiskeys(hcat(V)) == axiskeys(cat(V; dims=2)) == (['a', 'b', 'c'], Base.OneTo(1))
+
+    @test dimnames(vcat(M)) == dimnames(cat(M; dims=1)) == (:r, :c)
+    @test axiskeys(vcat(M)) == axiskeys(cat(M; dims=1)) == ('a':1:'c', 2:5)
+
+    @test dimnames(hcat(M)) == dimnames(cat(M, dims=2)) == (:r, :c)
+    @test axiskeys(hcat(M)) == axiskeys(cat(M, dims=2)) == ('a':1:'c', 2:5)
+
+    @test dimnames(cat(M; dims=3)) == (:r, :c, :_)
+    @test axiskeys(cat(M; dims=3)) == ('a':1:'c', 2:5, Base.OneTo(1))
 end
 @testset "matmul" begin