constprop through Val in ArraySpace (#295)

* constprop through Val in ArraySpace

* fix space

Author: jishnub

src/ApproxFunBase.jl

@@ -7,6 +7,7 @@ using Base, BlockArrays, BandedMatrices, BlockBandedMatrices, DomainSets,
               # Arpack
 
 import StaticArrays, Calculus
+using StaticArrays: SVector, @SArray, SArray
 
 import DomainSets: Domain, indomain, UnionDomain, ProductDomain, Point, ∂,
               elements, DifferenceDomain, Interval, ChebyshevInterval, boundary,
@@ -88,8 +89,6 @@ const BlockRange1 = BlockRange{1,Tuple{UnitRange{Int}}}
 
 import Base: view
 
-import StaticArrays: StaticArray, SVector
-
 import DomainSets: dimension
 
 import IntervalSets: (..), endpoints

src/Space.jl

@@ -638,7 +638,9 @@ for OP in (:maxspace,:(union))
 end
 
 space(x::Number) = ConstantSpace(typeof(x))
-space(f::AbstractArray{T}) where T<:Number = ArraySpace(ConstantSpace{T}(), size(f)...)
+_maybestaticsize(A) = size(A)
+_maybestaticsize(A::SArray) = Val(size(A))
+space(f::AbstractArray{T}) where T<:Number = ArraySpace(ConstantSpace(T), _maybestaticsize(f))
 
 setdomain(A::ConstantSpace{DD,R}, d) where {DD,R} = ConstantSpace{typeof(d),R}(d)
 

src/Spaces/ArraySpace.jl

@@ -20,6 +20,7 @@ const MatrixSpace{S,DD,RR,A<:AbstractMatrix{S}} = ArraySpace{S,2,DD,RR,A}
 #TODO: Think through domain/domaindominsion
 ArraySpace(sp::AbstractArray{SS,N}, f = first(sp)) where {SS<:Space,N} =
     ArraySpace{SS,N,domaintype(f),mapreduce(rangetype,promote_type,sp),typeof(sp)}(sp)
+ArraySpace(S::Space,::Val{n}) where {n} = ArraySpace(@SArray fill(S,n...))
 ArraySpace(S::Space,n::NTuple{N,Int}) where {N} = ArraySpace(fill(S,n))
 ArraySpace(S::Space,n::Integer) = ArraySpace(S,(n,))
 ArraySpace(S::Space,n,m) = ArraySpace(fill(S,(n,m)))

test/SpacesTest.jl

@@ -298,4 +298,17 @@ using LinearAlgebra
             @test (@inferred union(b, b)) == b
         end
     end
+
+    @testset "ArraySpace" begin
+        a = ApproxFunBase.ArraySpace(PointSpace(1:4), 2)
+        b = @inferred ApproxFunBase.ArraySpace(PointSpace(1:4), Val(2))
+        @test a == b
+        a = ApproxFunBase.ArraySpace(PointSpace(1:4), 2, 2)
+        b = @inferred ApproxFunBase.ArraySpace(PointSpace(1:4), Val((2,2)))
+        @test a == b
+
+        a = @inferred space(rand(2,2))
+        b = @inferred space(@SArray rand(2,2))
+        @test a == b
+    end
 end