handle offset indices

Author: jishnub

base/subarray.jl

@@ -310,7 +310,12 @@ end
 function getindex(V::FastContiguousSubArray, i::AbstractUnitRange{Int})
     @inline
     @boundscheck checkbounds(V, i)
-    @inbounds V.parent[V.offset1 .+ i]
+    out = similar(V, axes(i))
+    li = length(i)
+    if li > 0
+        copyto!(out, firstindex(out), V.parent, V.offset1 + first(i), li)
+    end
+    return out
 end
 
 # For vector views with linear indexing, we disambiguate to favor the stride/offset
@@ -330,7 +335,13 @@ end
 function getindex(V::FastContiguousSubArray{<:Any, 1}, i::AbstractUnitRange{Int})
     @inline
     @boundscheck checkbounds(V, i)
-    @inbounds V.parent[V.offset1 .+ i]
+    v = @view V.parent[V.offset1 .+ UnitRange(i)]
+    out = similar(V, axes(i))
+    li = length(i)
+    if li > 0
+        copyto!(out, firstindex(out), V.parent, V.offset1 + first(i), li)
+    end
+    return out
 end
 @inline getindex(V::FastContiguousSubArray, i::Colon) = getindex(V, to_indices(V, (:,))...)
 
@@ -356,7 +367,10 @@ end
 function setindex!(V::FastContiguousSubArray, x, i::AbstractUnitRange{Int})
     @inline
     @boundscheck checkbounds(V, i)
-    @inbounds V.parent[V.offset1 .+ i] = x
+    li = length(i)
+    if li > 0
+        copyto!(V.parent, V.offset1 + first(i), x, firstindex(x), li)
+    end
     V
 end
 
@@ -381,7 +395,10 @@ end
 function setindex!(V::FastContiguousSubArray{<:Any, 1}, x, i::AbstractUnitRange{Int})
     @inline
     @boundscheck checkbounds(V, i)
-    @inbounds V.parent[V.offset1 .+ i] = x
+    li = length(i)
+    if li > 0
+        copyto!(V.parent, V.offset1 + first(i), x, firstindex(x), li)
+    end
     V
 end
 @inline setindex!(V::FastSubArray, x, i::Colon) = setindex!(V, x, to_indices(V, (i,))...)

test/subarray.jl

@@ -463,6 +463,10 @@ end
                 c1 = @view a1[inds1]
                 @test c1[axes(c1,1)] == c1[:] == a1[inds1]
 
+                inds12 = Base.IdentityUnitRange(Base.OneTo(4))
+                c1 = @view a1[inds12]
+                @test c1[axes(c1,1)] == c1[:] == a1[inds12]
+
                 inds2 = 3:2:5
                 d1 = @view a1[inds2]
                 @test d1[axes(d1,1)] == d1[:] == a1[inds2]
@@ -486,50 +490,62 @@ end
                 c2 = @view a2[inds1]
                 @test c2[axes(c2,1)] == c2[:] == a2[inds1]
 
+                inds12 = Base.IdentityUnitRange(Base.OneTo(4))
+                c2 = @view a2[inds12]
+                @test c2[axes(c2,1)] == c2[:] == a2[inds12]
+
                 inds2 = 2:2:4
                 d2 = @view a2[inds2];
                 @test d2[axes(d2,1)] == d2[:] == a2[inds2]
             end
         end
     end
     @testset "setindex!" begin
-        a1 = rand(10);
-        a12 = copy(a1);
-        b1 = @view a1[:]; # 1D FastContiguousSubArray
-        c1 = @view a1[eachindex(a1)]; # 1D FastContiguousSubArray
-        d1 = @view a1[begin:1:end]; # 1D FastSubArray
-
-        ax1 = eachindex(a1);
-        @test (b1[ax1] = a12; b1) == (c1[ax1] = a12; c1) == (d1[ax1] = a12; d1) == (a1[ax1] = a12; a1)
-        @test (b1[:] = a12; b1) == (c1[:] = a12; c1) == (d1[:] = a12; d1) == (a1[:] = a12; a1)
-
-        # some arbitary indices
-        ind1 = 2:4
-        c1 = a12[ind1]
-        @test (c1[axes(c1,1)] = a12[ind1]; c1) == (c1[:] = a12[ind1]; c1) == a12[ind1]
-
-        ind2 = 2:2:8
-        d1 = a12[ind2]
-        @test (d1[axes(d1,1)] = a12[ind2]; d1) == (d1[:] = a12[ind2]; d1) == a12[ind2]
-
-        a2 = rand(10, 10);
-        a22 = copy(a2);
-        a2v = vec(a22);
-        b2 = @view a2[:, :]; # 2D FastContiguousSubArray
-        c2 = @view a2[eachindex(a2)]; # 1D FastContiguousSubArray
-        d2 = @view a2[begin:1:end]; # 1D FastSubArray
-
-        @test (b2[eachindex(b2)] = a2v; vec(b2)) == (c2[eachindex(c2)] = a2v; c2) == a2v
-        @test (d2[eachindex(d2)] = a2v; d2) == a2v
-
-        # some arbitary indices
-        inds1 = 3:9
-        c2 = @view a2[inds1]
-        @test (c2[eachindex(c2)] = @view(a22[inds1]); c2) == @view(a22[inds1])
-
-        inds2 = 3:3:9
-        d2 = @view a2[inds2]
-        @test (d2[eachindex(d2)] = @view(a22[inds2]); d2) == @view(a22[inds2])
+        @testset "1D" begin
+            a1 = rand(10);
+            a12 = copy(a1);
+            b1 = @view a1[:]; # 1D FastContiguousSubArray
+            c1 = @view a1[eachindex(a1)]; # 1D FastContiguousSubArray
+            d1 = @view a1[begin:1:end]; # 1D FastSubArray
+
+            ax1 = eachindex(a1);
+            @test (b1[ax1] = a12; b1) == (c1[ax1] = a12; c1) == (d1[ax1] = a12; d1) == (a1[ax1] = a12; a1)
+            @test (b1[:] = a12; b1) == (c1[:] = a12; c1) == (d1[:] = a12; d1) == (a1[:] = a12; a1)
+
+            # some arbitary indices
+            ind1 = 2:4
+            c1 = a12[ind1]
+            @test (c1[axes(c1,1)] = a12[ind1]; c1) == (c1[:] = a12[ind1]; c1) == a12[ind1]
+
+            ind2 = 2:2:8
+            d1 = a12[ind2]
+            @test (d1[axes(d1,1)] = a12[ind2]; d1) == (d1[:] = a12[ind2]; d1) == a12[ind2]
+        end
+
+        @testset "2D" begin
+            a2 = rand(10, 10);
+            a22 = copy(a2);
+            a2v = vec(a22);
+            b2 = @view a2[:, :]; # 2D FastContiguousSubArray
+            c2 = @view a2[eachindex(a2)]; # 1D FastContiguousSubArray
+            d2 = @view a2[begin:1:end]; # 1D FastSubArray
+
+            @test (b2[eachindex(b2)] = a2v; vec(b2)) == (c2[eachindex(c2)] = a2v; c2) == a2v
+            @test (d2[eachindex(d2)] = a2v; d2) == a2v
+
+            # some arbitary indices
+            inds1 = 3:9
+            c2 = @view a2[inds1]
+            @test (c2[eachindex(c2)] = @view(a22[inds1]); c2) == @view(a22[inds1])
+
+            inds1 = Base.IdentityUnitRange(Base.OneTo(4))
+            c2 = @view a2[inds1]
+            @test (c2[eachindex(c2)] = @view(a22[inds1]); c2) == @view(a22[inds1])
+
+            inds2 = 3:3:9
+            d2 = @view a2[inds2]
+            @test (d2[eachindex(d2)] = @view(a22[inds2]); d2) == @view(a22[inds2])
+        end
     end
 end