ismutable

Author: ChrisRackauckas

README.md

@@ -1,2 +1,40 @@
 # ArrayInterface.jl
-Designs for new Base array interface primates
+
+Julia has only recently reach v1.0 and the AbstractArray interface is still
+quite new. The purpose of this library is to solidify extensions to the current
+AbstractArray interface which are put to use in package ecosystems like
+DifferentialEquations.jl. Since these libraries are live, this package will
+serve as a staging ground for ideas before they merged into Base Julia. For this
+reason, no functionality is exported so that way if such functions are added
+and exported in a future Base Julia there will be no issues with the upgrade.
+
+## ismutable(x)
+
+A trait function for whether `x` is a mutable or immutable array. Used for
+dispatching to in-place and out-of-place versions of functions.
+
+## List of things to add
+
+https://github.com/JuliaLang/julia/issues/22216
+https://github.com/JuliaLang/julia/issues/22218
+https://github.com/JuliaLang/julia/issues/22622
+https://github.com/JuliaLang/julia/issues/25760
+https://github.com/JuliaLang/julia/issues/25107
+
+## Array Types to Handle
+
+The following common array types are being understood and tested as part of this
+development.
+
+- Array
+- Various versions of sparse arrays
+- SArray (by having a separate implementation of each algorithm for immutables)
+- MArray (we have a workaround for this issue: never use out of place broadcast https://github.com/JuliaDiffEq/OrdinaryDiffEq.jl/pull/546)
+- FieldVector
+- ArrayPartition
+- VectorOfArray
+- DistributedArrays
+- GPUArrays (CLArrays and CuArrays)
+- AFArrays
+- MultiScaleArrays
+- LabelledArrays

src/ArrayInterface.jl

@@ -1,3 +1,21 @@
 module ArrayInterface
 
+using Requires
+
+function ismutable end
+ismutable(x::Array) = true
+
+
+function __init__()
+
+  @require StaticArrays="90137ffa-7385-5640-81b9-e52037218182" begin
+    ismutable(x::StaticArrays.StaticArray) = false
+    ismutable(x::StaticArrays.MArray) = true
+  end
+
+  @require LabelledArrays="2ee39098-c373-598a-b85f-a56591580800" begin
+    ismutable(x::LVector) = ismutable(x.__x)
+  end
+end
+
 end

test/REQUIRE

@@ -0,0 +1,2 @@
+StaticArrays
+LabelledArrays

test/runtests.jl

@@ -1 +1,7 @@
+using ArrayInterface, Test
 
+@test ArrayInterface.ismutable(rand(3))
+
+using StaticArrays
+ArrayInterface.ismutable(@SVector [1,2,3]) == false
+ArrayInterface.ismutable(@MVector [1,2,3]) == true