Sort for RangeCumsum of OneToInf (#167)

* Sort for RangeCumsum of OneToInf

* Use cumsum instead of Rangecumsum in test

Author: jishnub

Project.toml

@@ -1,6 +1,6 @@
 name = "InfiniteArrays"
 uuid = "4858937d-0d70-526a-a4dd-2d5cb5dd786c"
-version = "0.13.6"
+version = "0.13.7"
 
 [deps]
 ArrayLayouts = "4c555306-a7a7-4459-81d9-ec55ddd5c99a"

src/infrange.jl

@@ -524,6 +524,9 @@ function union(r1::RangeCumsum{T1, OneToInf{T1}}, r2::RangeCumsum{T2, OneToInf{T
     T = promote_type(T1, T2)
     RangeCumsum(OneToInf{T}())
 end
+Base.issorted(r::RangeCumsum{<:Any,<:OneToInf}) = true
+Base.sort(r::RangeCumsum{<:Any,<:OneToInf}) = r
+Base.sort!(r::RangeCumsum{<:Any,<:OneToInf}) = r
 
 # vcat
 

test/runtests.jl

@@ -220,6 +220,13 @@ end
         @test sort(2:2:∞) ≡ sort!(2:2:∞) ≡ 2:2:∞
         @test_throws ArgumentError sort(2:-2:-∞)
         @test_throws ArgumentError sort!(2:-2:-∞)
+
+        @testset "RangeCumsum" begin
+            r = InfiniteArrays.OneToInf()
+            rs = cumsum(r)
+            @test sort(rs) === sort!(rs) === rs
+            @test @inferred((rs -> Val(issorted(rs)))(rs)) isa Val{true}
+        end
     end
     @testset "in" begin
         @test 0 in UInt(0):100:∞