Merge pull request #57 from chriselrod/sizedrangeinterfacestaticarrays

Add known_(first/last) methods for StaticArrays.SOneTo.

Author: ChrisRackauckas

Project.toml

@@ -1,6 +1,6 @@
 name = "ArrayInterface"
 uuid = "4fba245c-0d91-5ea0-9b3e-6abc04ee57a9"
-version = "2.10.0"
+version = "2.11.0"
 
 [deps]
 LinearAlgebra = "37e2e46d-f89d-539d-b4ee-838fcccc9c8e"

README.md

@@ -103,7 +103,8 @@ returns `one(Int)`.
 ## known_last(::Type{T})
 
 If `last` of instances of type `T` are known at compile time, return that
-last element. Otherwise, return `nothing`.
+last element. Otherwise, return `nothing`. For example,
+`known_last(StaticArrays.SOneTo{4})` returns 4.
 
 ## known_step(::Type{T})
 

src/ArrayInterface.jl

@@ -509,6 +509,8 @@ If `last` of an instance of type `T` is known at compile time, return it.
 Otherwise, return `nothing`.
 
 @test isnothing(known_last(typeof(1:4)))
+using StaticArrays
+@test known_last(typeof(SOneTo(4))) == 4
 """
 known_last(::Any) = nothing
 """
@@ -554,6 +556,9 @@ function __init__()
       StaticArrays.SArray{S}(y)
     end
 
+    known_first(::Type{<:StaticArrays.SOneTo}) = 1
+    known_last(::Type{StaticArrays.SOneTo{N}}) where {N} = N
+
     @require Adapt="79e6a3ab-5dfb-504d-930d-738a2a938a0e" begin
       function Adapt.adapt_storage(::Type{<:StaticArrays.SArray{S}},xs::Array) where S
           StaticArrays.SArray{S}(xs)

test/runtests.jl

@@ -8,6 +8,8 @@ using StaticArrays
 @test ArrayInterface.ismutable(@MVector [1,2,3]) == true
 @test ArrayInterface.ismutable(1:10) == false
 @test ArrayInterface.ismutable((0.1,1.0)) == false
+@test isone(ArrayInterface.known_first(typeof(StaticArrays.SOneTo(7))))
+@test ArrayInterface.known_last(typeof(StaticArrays.SOneTo(7))) == 7
 
 using LinearAlgebra, SparseArrays