Add tests for reshape with an omitted dimension

base/reshapedarray.jl

@@ -43,7 +43,7 @@ length(R::ReshapedArrayIterator) = length(R.iter)
 Return an array with the same data as the given array, but with different dimensions.
 
 The new dimensions may be specified either as a list of arguments or as a shape
-tuple. Up to one dimension may be specified with a `:`, in which case its
+tuple. At most one dimension may be specified with a `:`, in which case its
 length is computed such that its product with all the specified dimensions is
 equal to the length of the original array A.
 
@@ -88,8 +88,10 @@ reshape(parent::AbstractArray, shp::NeedsShaping) = reshape(parent, to_shape(shp
 reshape(parent::AbstractArray, dims::Dims)        = _reshape(parent, dims)
 
 # Allow missing dimensions with Colon():
+reshape(parent::AbstractArray, dims::Int...) = _reshape(parent, dims)
 reshape(parent::AbstractArray, dims::Union{Int,Colon}...) = reshape(parent, dims)
-reshape(parent::AbstractArray, dims::Tuple{Vararg{Union{Int,Colon}}}) = _reshape(parent, _reshape_uncolon(A, dims))
+reshape(parent::AbstractArray, dims::Tuple{Vararg{Int}}) = _reshape(parent, dims)
+reshape(parent::AbstractArray, dims::Tuple{Vararg{Union{Int,Colon}}}) = _reshape(parent, _reshape_uncolon(parent, dims))
 # Recursively move dimensions to pre and post tuples, splitting on the Colon
 @inline _reshape_uncolon(A, dims) = _reshape_uncolon(A, (), nothing, (), dims)
 @inline _reshape_uncolon(A, pre, c::Void,  post, dims::Tuple{Any, Vararg{Any}}) =
@@ -99,7 +101,7 @@ reshape(parent::AbstractArray, dims::Tuple{Vararg{Union{Int,Colon}}}) = _reshape
 @inline _reshape_uncolon(A, pre, c::Colon, post, dims::Tuple{Any, Vararg{Any}}) =
     _reshape_uncolon(A, pre, c, (post..., dims[1]), tail(dims))
 _reshape_uncolon(A, pre, c::Colon, post, dims::Tuple{Colon, Vararg{Any}}) =
-    throw(DimensionMismatch("new dimensions $((pre..., c, post..., dims...)) may only have up to one omitted dimension specified by Colon()"))
+    throw(DimensionMismatch("new dimensions $((pre..., c, post..., dims...)) may only have at most one omitted dimension specified by Colon()"))
 @inline function _reshape_uncolon(A, pre, c::Colon, post, dims::Tuple{})
     sz, remainder = divrem(length(A), prod(pre)*prod(post))
     remainder == 0 || _throw_reshape_colon_dimmismatch(A, pre, post)

test/arrayops.jl

@@ -135,6 +135,27 @@ end
         @test isa(reshape(s, Val{N}), Base.ReshapedArray{Int,N})
     end
 end
+@testset "reshape with colon" begin
+    # Reshape with an omitted dimension
+    let A = linspace(1, 60, 60)
+        @test size(reshape(A, :))         == (60,)
+        @test size(reshape(A, :, 1))      == (60, 1)
+        @test size(reshape(A, (:, 2)))    == (30, 2)
+        @test size(reshape(A, 3, :))      == (3, 20)
+        @test size(reshape(A, 2, 3, :))   == (2, 3, 10)
+        @test size(reshape(A, (2, :, 5))) == (2, 6, 5)
+        @test_throws DimensionMismatch reshape(A, 7, :)
+        @test_throws DimensionMismatch reshape(A, :, 2, 3, 4)
+        @test_throws DimensionMismatch reshape(A, (:, :))
+
+        B = rand(2,2,2,2)
+        @test size(reshape(B, :)) == (16,)
+        @test size(reshape(B, :, 4)) == (4, 4)
+        @test size(reshape(B, (2, 1, :))) == (2, 1, 8)
+        @test_throws DimensionMismatch reshape(B, 3, :)
+        @test_throws DimensionMismatch reshape(B, :, :, 2, 2)
+    end
+end
 
 @test reshape(1:5, (5,)) === 1:5
 @test reshape(1:5, 5) === 1:5