Remove unnecessary reshape methods (#367)

* Remove unnecessary `reshape` methods

* version-limit methods with Colon

* Require at least one `Integer` in `reshape` method

* Add `BigInt` tests

* Specific test for `Integer` reshaping

* Move  MyBigFill`struct defn to global scope

* Update `MyBigFill` methods in test

Author: jishnub

src/OffsetArrays.jl

@@ -376,16 +376,13 @@ _reshape2(A::OffsetArray, inds) = reshape(parent(A), inds)
 _reshape_nov(A, inds) = _reshape(no_offset_view(A), inds)
 
 # And for non-offset axes, we can just return a reshape of the parent directly
-Base.reshape(A::OffsetArray, inds::Tuple{Union{Integer,Base.OneTo},Vararg{Union{Integer,Base.OneTo}}}) = _reshape_nov(A, inds)
+Base.reshape(A::OffsetArray, inds::Tuple{Integer,Vararg{Integer}}) = _reshape_nov(A, inds)
 Base.reshape(A::OffsetArray, inds::Dims) = _reshape_nov(A, inds)
-Base.reshape(A::OffsetVector, ::Colon) = A
-Base.reshape(A::OffsetVector, ::Tuple{Colon}) = A
-Base.reshape(A::OffsetArray, inds::Union{Int,Colon}...) = reshape(A, inds)
-Base.reshape(A::OffsetArray, inds::Tuple{Vararg{Union{Int,Colon}}}) = _reshape_nov(A, inds)
-# The following two additional methods for Colon are added to resolve method ambiguities to
-# Base: https://github.com/JuliaLang/julia/pull/45387#issuecomment-1132859663
-Base.reshape(A::OffsetArray, inds::Colon) = reshape(parent(A), inds)
-Base.reshape(A::OffsetArray, inds::Tuple{Colon}) = reshape(parent(A), inds)
+if VERSION < v"1.10.7"
+    # the specialized reshape(parent::AbstractVector, ::Tuple{Colon}) is available in Base at least on this version
+    Base.reshape(A::OffsetVector, ::Tuple{Colon}) = A
+    Base.reshape(A::OffsetArray, inds::Tuple{Vararg{Union{Int,Colon}}}) = _reshape_nov(A, inds)
+end
 
 # permutedims in Base does not preserve axes, and can not be fixed in a non-breaking way
 # This is a stopgap solution

test/runtests.jl

@@ -1749,6 +1749,28 @@ end
     end
 end
 
+# custom FillArray with BigInt axes, used to test `reshape`
+struct MyBigFill{T,N} <: AbstractArray{T,N}
+    val :: T
+    axes :: NTuple{N,Base.OneTo{BigInt}}
+end
+MyBigFill(val, sz::NTuple{N,BigInt}) where {N} = MyBigFill(val, map(Base.OneTo, sz))
+MyBigFill(val, sz::Tuple{Vararg{Integer}}) = MyBigFill(val, map(BigInt, sz))
+Base.size(M::MyBigFill) = map(length, M.axes)
+Base.axes(M::MyBigFill) = M.axes
+function Base.getindex(M::MyBigFill{<:Any,N}, ind::Vararg{Integer,N}) where {N}
+    checkbounds(M, ind...)
+    M.val
+end
+function Base.isassigned(M::MyBigFill{<:Any,N}, ind::Vararg{BigInt,N}) where {N}
+    checkbounds(M, ind...)
+    true
+end
+function Base.reshape(M::MyBigFill, ind::NTuple{N,BigInt}) where {N}
+    length(M) == prod(ind) || throw(ArgumentError("length mismatch in reshape"))
+    MyBigFill(M.val, ind)
+end
+
 @testset "reshape" begin
     A0 = [1 3; 2 4]
     A = OffsetArray(A0, (-1,2))
@@ -1846,10 +1868,11 @@ end
     @test axes(R) == (1:2, 1:3)
 
     r = OffsetArray(ZeroBasedRange(3:4), 1);
-    @test reshape(r, 2) == 3:4
-    @test reshape(r, (2,)) == 3:4
+    @test reshape(r, 2) == reshape(r, big(2)) == 3:4
+    @test reshape(r, (2,)) == reshape(r, (big(2),)) == 3:4
     @test reshape(r, :) == 3:4
     @test reshape(r, (:,)) == 3:4
+    @test reshape(r, big(2), 1) == reshape(3:4, 2, 1)
 
     # getindex for a reshaped array that wraps an offset array is broken on 1.0
     if VERSION >= v"1.1"
@@ -1901,6 +1924,11 @@ end
     catch e
         e isa TypeError || rethrow()
     end
+    @testset "Tuple{Vararg{Integer}}" begin
+        M = MyBigFill(4, (2, 3))
+        O = OffsetArray(M)
+        @test vec(O) isa MyBigFill
+    end
 end
 
 @testset "permutedims" begin