From b8753a59b0e973c957f971da543fb60381020f48 Mon Sep 17 00:00:00 2001
From: Jishnu Bhattacharya <jishnub@users.noreply.github.com>
Date: Thu, 29 Apr 2021 11:11:17 +0400
Subject: [PATCH] Reshape accepts a single colon for AbstractArrays (#220)

* reshape accepts one colon for AbstractArrays

* Add tests with different ndims

* fix offset for colon
---
 src/utils.jl     |  2 +-
 test/runtests.jl | 21 +++++++++++++++++++++
 2 files changed, 22 insertions(+), 1 deletion(-)

diff --git a/src/utils.jl b/src/utils.jl
index 8299f598..392f0316 100644
--- a/src/utils.jl
+++ b/src/utils.jl
@@ -11,7 +11,7 @@ _strip_IdOffsetRange(r::IdOffsetRange) = parent(r)
 _strip_IdOffsetRange(r) = r
 
 _offset(axparent::AbstractUnitRange, ax::AbstractUnitRange) = first(ax) - first(axparent)
-_offset(axparent::AbstractUnitRange, ax::Integer) = 1 - first(axparent)
+_offset(axparent::AbstractUnitRange, ::Union{Integer, Colon}) = 1 - first(axparent)
 
 """
     OffsetArrays.AxisConversionStyle(typeof(indices))
diff --git a/test/runtests.jl b/test/runtests.jl
index 110c6adc..162d2d7e 100644
--- a/test/runtests.jl
+++ b/test/runtests.jl
@@ -1496,6 +1496,27 @@ end
     @test reshape(OffsetArray(-1:0, -1:0), :) == OffsetArray(-1:0, -1:0)
     @test reshape(A, :) == reshape(A0, :)
 
+    # reshape with one Colon for AbstractArrays
+    B = reshape(A0, -10:-9, :)
+    @test B isa OffsetArray{Int,2}
+    @test parent(B) === A0
+    @test axes(B, 1) == -10:-9
+    @test axes(B, 2) == axes(A0, 2)
+
+    B = reshape(A0, -10:-9, 3:3, :)
+    @test B isa OffsetArray{Int,3}
+    @test same_value(A0, B)
+    @test axes(B, 1) == -10:-9
+    @test axes(B, 2) == 3:3
+    @test axes(B, 3) == 1:2
+
+    B = reshape(A0, -10:-9, 3:4, :)
+    @test B isa OffsetArray{Int,3}
+    @test same_value(A0, B)
+    @test axes(B, 1) == -10:-9
+    @test axes(B, 2) == 3:4
+    @test axes(B, 3) == 1:1
+
     # pop the parent
     B = reshape(A, size(A))
     @test B == A0