Simplify containsconstant trait (#492)

* Simplify containsconstant trait

* Version bump to v0.8.38

* promote_rule test for constantless space

Author: jishnub

Project.toml

@@ -1,6 +1,6 @@
 name = "ApproxFunBase"
 uuid = "fbd15aa5-315a-5a7d-a8a4-24992e37be05"
-version = "0.8.37"
+version = "0.8.38"
 
 [deps]
 AbstractFFTs = "621f4979-c628-5d54-868e-fcf4e3e8185c"
@@ -20,7 +20,6 @@ IntervalSets = "8197267c-284f-5f27-9208-e0e47529a953"
 LazyArrays = "5078a376-72f3-5289-bfd5-ec5146d43c02"
 LinearAlgebra = "37e2e46d-f89d-539d-b4ee-838fcccc9c8e"
 LowRankApprox = "898213cb-b102-5a47-900c-97e73b919f73"
-SimpleTraits = "699a6c99-e7fa-54fc-8d76-47d257e15c1d"
 SparseArrays = "2f01184e-e22b-5df5-ae63-d93ebab69eaf"
 SpecialFunctions = "276daf66-3868-5448-9aa4-cd146d93841b"
 StaticArrays = "90137ffa-7385-5640-81b9-e52037218182"
@@ -50,7 +49,6 @@ IntervalSets = "0.5, 0.6, 0.7"
 LazyArrays = "0.20, 0.21, 0.22, 1"
 LowRankApprox = "0.2, 0.3, 0.4, 0.5"
 OddEvenIntegers = "0.1.8"
-SimpleTraits = "0.9"
 SpecialFunctions = "0.10, 1.0, 2"
 Static = "0.8"
 StaticArrays = "0.12, 1.0"

src/ApproxFunBase.jl

@@ -3,8 +3,7 @@ using Base: AnyDict
 using Base, BlockArrays, BandedMatrices, BlockBandedMatrices, DomainSets,
               IntervalSets, SpecialFunctions, AbstractFFTs, FFTW,
               SpecialFunctions, DSP, DualNumbers, LinearAlgebra, SparseArrays,
-              LowRankApprox, FillArrays, InfiniteArrays, InfiniteLinearAlgebra,
-              SimpleTraits
+              LowRankApprox, FillArrays, InfiniteArrays, InfiniteLinearAlgebra
 
 import StaticArrays, Calculus
 using StaticArrays: SVector, @SArray, SArray
@@ -96,8 +95,6 @@ import DomainSets: dimension
 
 import IntervalSets: (..), endpoints
 
-using SimpleTraits
-
 const Vec{d,T} = SVector{d,T}
 
 export pad!, pad, chop!, sample,

src/Spaces/ConstantSpace.jl

@@ -31,53 +31,40 @@ coefficients(cfs::AbstractVector,::SequenceSpace) = cfs  # all vectors are conve
 
 ## Constant space defintions
 
-@traitdef ContainsConstant{X}
-@traitimpl ContainsConstant{X} <- containsconstant(X)
+containsconstant(A::Space) = containsconstant(typeof(A))
+containsconstant(@nospecialize(_)) = Val(false)
 
-containsconstant(@nospecialize(_)) = false
-
-promote_rule(TS1::Type{<:ConstantSpace}, TS2::Type{<:Space}) =
-    constspace_promote_rule(TS1, TS2)
-
-@traitfn function constspace_promote_rule(::Type{<:ConstantSpace},
-            B::Type{X}) where {X; !ContainsConstant{X}}
-    Union{}
+# setup conversions for spaces that contain constants
+macro containsconstants(SP)
+    esc(quote
+        ApproxFunBase.containsconstant(::Type{<:$SP}) = Val(true)
+    end)
 end
-@traitfn function constspace_promote_rule(::Type{<:ConstantSpace},
-            B::Type{X}) where {X; ContainsConstant{X}}
-    B
+
+function promote_rule(TS1::Type{<:ConstantSpace}, ::Type{TS2}) where {TS2<:Space}
+    constspace_promote_rule(TS1, TS2, containsconstant(TS2))
 end
+constspace_promote_rule(::Type{<:ConstantSpace}, ::Type{<:Space}, ::Val{false}) = Union{}
+constspace_promote_rule(::Type{<:ConstantSpace}, ::Type{B}, ::Val{true}) where {B<:Space} = B
 
-union_rule(A::ConstantSpace, B::Space) = constspace_union_rule(A, B)
+union_rule(A::ConstantSpace, B::Space) = constspace_union_rule(A, B, containsconstant(B))
 # TODO: this seems like it needs more thought
-@traitfn constspace_union_rule(A::ConstantSpace, B::X) where {X; !ContainsConstant{X}} =
-    ConstantSpace(domain(B))⊕B
-@traitfn constspace_union_rule(A::ConstantSpace, B::X) where {X; ContainsConstant{X}} = B
-
-promote_rule(TF::Type{<:Fun}, TN::Type{<:Number}) = fun_promote_rule(TF, TN)
+function constspace_union_rule(@nospecialize(_::ConstantSpace), B::Space, ::Val{false})
+    ConstantSpace(domain(B)) ⊕ B
+end
+constspace_union_rule(@nospecialize(_::ConstantSpace), B::Space, ::Val{true}) = B
 
-@traitfn fun_promote_rule(::Type{<:Fun{S,CT}},
-            ::Type{T}) where {T<:Number,CT,S; !ContainsConstant{S}} = Fun
-@traitfn function fun_promote_rule(::Type{<:Fun{S,CT}},
-            ::Type{T}) where {T<:Number,CT,S; ContainsConstant{S}}
+function promote_rule(TF::Type{<:Fun{S}}, TN::Type{<:Number}) where {S}
+    fun_promote_rule(TF, TN, containsconstant(S))
+end
+fun_promote_rule(::Type{<:Fun}, ::Type{<:Number}, ::Val{false}) = Fun
+function fun_promote_rule(::Type{<:Fun{S,CT}}, ::Type{T}, ::Val{true}) where {T<:Number,CT,S}
     ApproxFunBase.VFun{S,promote_type(CT,T)}
 end
-@traitfn fun_promote_rule(::Type{Fun{S}},
-            ::Type{T}) where {T<:Number,S; !ContainsConstant{S}} = Fun
-@traitfn function fun_promote_rule(::Type{<:Fun{S}},
-            ::Type{T}) where {T<:Number,S; ContainsConstant{S}}
+function fun_promote_rule(::Type{<:Fun{S}}, ::Type{T}, ::Val{true}) where {T<:Number,S}
     ApproxFunBase.VFun{S,T}
 end
 
-# setup conversions for spaces that contain constants
-macro containsconstants(SP)
-    esc(quote
-        ApproxFunBase.containsconstant(::Type{<:$SP}) = true
-    end)
-end
-
-
-
 Fun(c::Number) = Fun(ConstantSpace(typeof(c)),[c])
 Fun(c::Number,d::ConstantSpace) = Fun(d,[c])
 

test/PolynomialSpacesTests.jl

@@ -27,7 +27,7 @@ ApproxFunBase.domainscompatible(a::UniqueInterval, b::UniqueInterval) = a == b
 
 Base.:(==)(a::UniqueInterval, b::UniqueInterval) = (@assert a.parentinterval == b.parentinterval; true)
 
-@testset "ApproxFunBase" begin
+@testset "PolynomialSpaces" begin
     @testset "Constructor" begin
         @test (@inferred Fun()) == Fun(x->x, Chebyshev())
         @test (@inferred norm(Fun())) ≈ norm(Fun(), 2) ≈ √(2/3) # √∫x^2 dx over -1..1
@@ -367,6 +367,24 @@ Base.:(==)(a::UniqueInterval, b::UniqueInterval) = (@assert a.parentinterval ==
         A = @inferred Derivative() * Multiplication(x, Chebyshev())
         @test A * x ≈ 2x
     end
+
+    @testset "ConstantSpace" begin
+        S = Chebyshev()
+        d = domain(S)
+        C = ConstantSpace(d)
+        @test promote_type(typeof(S), typeof(C)) == typeof(S)
+        @test promote_type(typeof(S|(2:3)), typeof(C)) <: Space{typeof(d)}
+
+        @test union(S, C) == S
+        # space doesn't contain constant
+        cmps = union(S|(2:4), C)
+        @test C in components(cmps)
+        @test S|(2:4) in components(cmps)
+
+        @test promote_type(typeof(Fun()), Float64) == typeof(Fun())
+        @test [Fun(), 1] isa Vector{typeof(Fun())}
+        @test promote_type(Fun{typeof(Chebyshev())}, Float64) == typeof(Fun())
+    end
 end
 
 end # module