Preserve axes in permutedims for AbstractVectors (#243)

* preserve axes in permutedims for AbstractVectors

* fix stackoverflow in reshape

* conditionally pop parent array in reshape

* add test for 2D permutedims

Author: jishnub

src/OffsetArrays.jl

@@ -349,7 +349,8 @@ _similar_axes_or_length(AT, ax::I, ::I) where {I} = similar(AT, map(_indexlength
 Base.reshape(A::AbstractArray, inds::OffsetAxis...) = reshape(A, inds)
 function Base.reshape(A::AbstractArray, inds::Tuple{OffsetAxis,Vararg{OffsetAxis}})
     AR = reshape(A, map(_indexlength, inds))
-    return OffsetArray(AR, map(_offset, axes(AR), inds))
+    O = OffsetArray(AR, map(_offset, axes(AR), inds))
+    return _popreshape(O, axes(AR), _filterreshapeinds(inds))
 end
 
 # Reshaping OffsetArrays can "pop" the original OffsetArray wrapper and return
@@ -364,6 +365,10 @@ Base.reshape(A::OffsetVector, ::Colon) = A
 Base.reshape(A::OffsetArray, inds::Union{Int,Colon}...) = reshape(parent(A), inds)
 Base.reshape(A::OffsetArray, inds::Tuple{Vararg{Union{Int,Colon}}}) = reshape(parent(A), inds)
 
+# permutedims in Base does not preserve axes, and can not be fixed in a non-breaking way
+# This is a stopgap solution
+Base.permutedims(v::OffsetVector) = reshape(v, (1, axes(v, 1)))
+
 Base.fill(v, inds::NTuple{N, Union{Integer, AbstractUnitRange}}) where {N} =
     fill!(similar(Array{typeof(v)}, inds), v)
 Base.zeros(::Type{T}, inds::NTuple{N, Union{Integer, AbstractUnitRange}}) where {T, N} =

src/utils.jl

@@ -4,7 +4,7 @@ _indexoffset(r::AbstractRange) = first(r) - 1
 _indexoffset(i::Integer) = 0
 _indexoffset(i::Colon) = 0
 _indexlength(r::AbstractRange) = length(r)
-_indexlength(i::Integer) = i
+_indexlength(i::Integer) = Int(i)
 _indexlength(i::Colon) = Colon()
 
 _strip_IdOffsetRange(r::IdOffsetRange) = parent(r)
@@ -102,3 +102,11 @@ end
 
 _of_eltype(::Type{T}, M::AbstractArray{T}) where {T} = M
 _of_eltype(T, M::AbstractArray) = map(T, M)
+
+# filter the arguments to reshape to check if there are any ranges
+# If not, we may pop the parent array
+_filterreshapeinds(t::Tuple{AbstractUnitRange, Vararg{Any}}) = t
+_filterreshapeinds(t::Tuple) = _filterreshapeinds(tail(t))
+_filterreshapeinds(t::Tuple{}) = t
+_popreshape(A::AbstractArray, ax::Tuple{Vararg{Base.OneTo}}, inds::Tuple{}) = no_offset_view(A)
+_popreshape(A::AbstractArray, ax, inds) = A

test/runtests.jl

@@ -1767,6 +1767,39 @@ end
     Arsc = reshape(A, :, 1)
     Arsc[1,1] = 5
     @test first(A) == 5
+
+    @testset "issue #235" begin
+        Vec64  = zeros(6)
+        ind_a_64 = 3
+        ind_a_32 =Int32.(ind_a_64)
+        @test reshape(Vec64, ind_a_32, :) == reshape(Vec64, ind_a_64, :)
+    end
+
+    R = reshape(zeros(6), 2, :)
+    @test R isa Matrix
+    @test axes(R) == (1:2, 1:3)
+    R = reshape(zeros(6,1), 2, :)
+    @test R isa Matrix
+    @test axes(R) == (1:2, 1:3)
+
+    R = reshape(zeros(6), 1:2, :)
+    @test axes(R) == (1:2, 1:3)
+    R = reshape(zeros(6,1), 1:2, :)
+    @test axes(R) == (1:2, 1:3)
+end
+
+@testset "permutedims" begin
+    a = OffsetArray(1:2, 2:3)
+    @test permutedims(a) == reshape(1:2, 1, 2:3)
+    a = OffsetArray([10,11], Base.OneTo(2))
+    @test permutedims(a) == reshape(10:11, 1, 1:2)
+    a = OffsetArray(SVector{2}(1,2), 3:4)
+    @test permutedims(a) == reshape(1:2, 1, 3:4)
+
+    # check that the 2D case is unaffected
+    a = OffsetArray(reshape(1:2, 1, 2), 2:2, 4:5)
+    b = permutedims(a)
+    @test a[2,:] == b[:,2]
 end
 
 @testset "Indexing with OffsetArray axes" begin