Backport: Improve type-inference in multiplying with TimesOperator (#588)

* Backport: Improve type-inference in multiplying with TimesOperator

* Remove ProductSpace test

Author: jishnub

.github/workflows/ci.yml

@@ -49,7 +49,7 @@ jobs:
         arch:
           - x64
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
       - uses: julia-actions/setup-julia@v1
         with:
           version: ${{ matrix.version }}

.github/workflows/downstream.yml

@@ -5,6 +5,10 @@ on:
       - master
       - backport**
     tags: '*'
+    paths-ignore:
+      - 'LICENSE'
+      - 'README.md'
+      - '.github/workflows/TagBot.yml'
   pull_request:
     paths-ignore:
       - 'LICENSE'
@@ -42,14 +46,14 @@ jobs:
           - {repo: ApproxFunSingularities.jl, group: JuliaApproximation}
 
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
       - uses: julia-actions/setup-julia@v1
         with:
           version: ${{ matrix.julia-version }}
           arch: x64
       - uses: julia-actions/julia-buildpkg@latest
       - name: Clone Downstream
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
         with:
           repository: ${{ matrix.package.group }}/${{ matrix.package.repo }}
           path: downstream

Project.toml

@@ -1,6 +1,6 @@
 name = "ApproxFunBase"
 uuid = "fbd15aa5-315a-5a7d-a8a4-24992e37be05"
-version = "0.8.56"
+version = "0.8.57"
 
 [deps]
 AbstractFFTs = "621f4979-c628-5d54-868e-fcf4e3e8185c"

README.md

@@ -1,14 +1,16 @@
 # ApproxFunBase.jl
 Core functionality of ApproxFun
 
-[![](https://img.shields.io/badge/docs-stable-blue.svg)](https://JuliaApproximation.github.io/ApproxFun.jl/stable)
-[![](https://img.shields.io/badge/docs-dev-blue.svg)](https://JuliaApproximation.github.io/ApproxFun.jl/dev)
 [![CI](https://github.com/JuliaApproximation/ApproxFunBase.jl/actions/workflows/ci.yml/badge.svg)](https://github.com/JuliaApproximation/ApproxFunBase.jl/actions/workflows/ci.yml)
 [![IntegrationTest](https://github.com/JuliaApproximation/ApproxFunBase.jl/actions/workflows/downstream.yml/badge.svg)](https://github.com/JuliaApproximation/ApproxFunBase.jl/actions/workflows/downstream.yml)
 [![codecov](https://codecov.io/gh/JuliaApproximation/ApproxFunBase.jl/branch/master/graph/badge.svg)](https://codecov.io/gh/JuliaApproximation/ApproxFunBase.jl)
 [![Aqua QA](https://raw.githubusercontent.com/JuliaTesting/Aqua.jl/master/badge.svg)](https://github.com/JuliaTesting/Aqua.jl)
 [![deps](https://juliahub.com/docs/ApproxFunBase/deps.svg)](https://juliahub.com/ui/Packages/ApproxFunBase/deO92?t=2)
 [![version](https://juliahub.com/docs/ApproxFunBase/version.svg)](https://juliahub.com/ui/Packages/ApproxFunBase/deO92)
+[![pkgeval](https://juliahub.com/docs/General/ApproxFunBase/stable/pkgeval.svg)](https://juliahub.com/ui/Packages/General/ApproxFunBase)
+
+[![](https://img.shields.io/badge/docs-stable-blue.svg)](https://JuliaApproximation.github.io/ApproxFun.jl/stable)
+[![](https://img.shields.io/badge/docs-dev-blue.svg)](https://JuliaApproximation.github.io/ApproxFun.jl/dev)
 [![Join the chat at https://gitter.im/JuliaApproximation/ApproxFun.jl](https://badges.gitter.im/JuliaApproximation/ApproxFun.jl.svg)](https://gitter.im/JuliaApproximation/ApproxFun.jl?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge&utm_content=badge)
 
 

src/Operators/banded/Multiplication.jl

@@ -77,15 +77,21 @@ getindex(D::ConcreteMultiplication{F,UnsetSpace,T},k::Integer,j::Integer) where
 
 
 ##multiplication can always be promoted, range space is allowed to change
-promotedomainspace(D::Multiplication,sp::UnsetSpace) = D
-promotedomainspace(D::Multiplication,sp::Space) = Multiplication(D.f,sp)
-promoterangespace(D::ConcreteMultiplication{P,UnsetSpace},sp::UnsetSpace) where {P} = D
-promoterangespace(D::ConcreteMultiplication{P,UnsetSpace},sp::Space) where {P} =
+promotedomainspace(D::Multiplication, sp::UnsetSpace) = D
+function promotedomainspace(D::Multiplication, sp::Space)
+    if domainspace(D) === sp
+        D
+    else
+        Multiplication(D.f,sp)
+    end
+end
+promoterangespace(D::ConcreteMultiplication{P,UnsetSpace}, sp::UnsetSpace) where {P} = D
+promoterangespace(D::ConcreteMultiplication{P,UnsetSpace}, sp::Space) where {P} =
     promoterangespace(Multiplication(D.f,ConstantSpace(domain(sp))), sp)
 
-choosedomainspace(M::ConcreteMultiplication{D,UnsetSpace},::UnsetSpace) where {D} = space(M.f)
+choosedomainspace(M::ConcreteMultiplication{D,UnsetSpace}, ::UnsetSpace) where {D} = space(M.f)
 # we assume multiplication maps spaces to themselves
-choosedomainspace(M::ConcreteMultiplication{D,UnsetSpace},sp::Space) where {D} = sp
+choosedomainspace(M::ConcreteMultiplication{D,UnsetSpace}, sp::Space) where {D} = sp
 
 
 diagm(a::Fun) = Multiplication(a)

src/Operators/general/algebra.jl

@@ -80,7 +80,7 @@ end
 
 domain(P::PlusOperator) = commondomain(P.ops)
 
-_extractops(A, ::Any) = SVector{1}(A)
+_extractops(A, ::Any) = [A]
 _extractops(A::PlusOperator, ::typeof(+)) = A.ops
 
 function +(A::Operator, B::Operator)
@@ -281,6 +281,9 @@ struct TimesOperator{T,BW,SZ,O<:Operator{T},BBW,SBBW} <: Operator{T}
     end
 end
 
+operatortype(::T) where {T<:Operator} = T
+operatortype(::TimesOperator{<:Any,<:Any,<:Any,O}) where {O} = O
+
 const PlusOrTimesOp = Union{PlusOperator,TimesOperator}
 
 bandwidthssum(f, ops) = mapfoldl(f, (t1, t2) -> t1 .+ t2, ops, init=(0, 0))
@@ -351,8 +354,10 @@ end
     anytimesop = any(x -> x isa TimesOperator, ops)
     TimesOperator(convert_vector(ops), bw, sz, bbw, sbbw, ibbb, irb, isaf; anytimesop)
 end
+maybenarroweltype(::AbstractVector{Operator{T}}) where {T} = Operator{T}
+maybenarroweltype(opsin) = mapreduce(operatortype, promote_type, opsin)
 function __promotetimes(opsin, dsp, anytimesop)
-    ops = Vector{Operator{promote_eltypeof(opsin)}}(undef, 0)
+    ops = Vector{maybenarroweltype(opsin)}(undef, 0)
     sizehint!(ops, length(opsin))
 
     for k in reverse(eachindex(opsin))
@@ -633,7 +638,7 @@ function A_mul_B(A::Operator, B::Operator; dspB=domainspace(B), rspA=rangespace(
     elseif isconstop(B)
         promotedomainspace(strictconvert(Number, B) * A, dspB)
     else
-        promotetimes(collateops(*, A, B), dspB, false)
+        promotetimes(collateops(*, A : rangespace(B), B), dspB, false)
     end
 end
 

test/show.jl

@@ -11,7 +11,7 @@
 		@testset "ConstantSpace" begin
 			@test contains(repr(ConstantSpace()), "ConstantSpace")
 			c = ConstantSpace(0..1)
-			@test contains(repr(c), "ConstantSpace")
+			@test startswith(repr(c), "ConstantSpace")
 			@test contains(repr(c), repr(domain(c)))
 		end
 		@testset "TensorSpace" begin
@@ -32,7 +32,7 @@
 			p = PointSpace(1:4)
 			ps = PiecewiseSpace(p)
 			rpr = repr(ps)
-			@test contains(rpr, "PiecewiseSpace")
+			@test startswith(rpr, "PiecewiseSpace")
 			@test contains(rpr, repr(p))
 		end
 		@testset "ArraySpace" begin