Implement promotion (#21)

* Implement promotion

* Back to master

Author: blegat

.github/workflows/ci.yml

@@ -30,7 +30,7 @@ jobs:
         run: |
           using Pkg
           Pkg.add([
-              PackageSpec(name="MathOptInterface", rev="bl/constraint_not_inv"),
+              PackageSpec(name="MathOptInterface", rev="master"),
           ])
       - uses: julia-actions/julia-buildpkg@v1
       - uses: julia-actions/julia-runtest@v1

src/sets.jl

@@ -194,8 +194,15 @@ function Base.getindex(m::Factorization, i::Int, j::Int)
     )
 end
 
+function Base.promote_rule(
+    ::Type{Factorization{T,M,S1}},
+    ::Type{Factorization{T,V,S2}},
+) where {T,M<:AbstractMatrix{T},V<:AbstractVector{T},S1,S2}
+    return Factorization{T,M,S1}
+end
+
 function Base.convert(
-    ::Type{<:Factorization{T,F,V}},
+    ::Type{Factorization{T,F,V}},
     f::Factorization{S,<:AbstractVector{S},<:AbstractArray{S,0}},
 ) where {T,S,F<:AbstractMatrix{T},V<:AbstractVector{T}}
     return Factorization{T,F,V}(

test/sets.jl

@@ -71,6 +71,17 @@ end
 
 _test_convert(f, a, b) = _test_convert(f(a), f(b))
 
+function test_promotion()
+    F = ones(2, 2)
+    f = ones(2)
+    a = LRO.Factorization(F, ones(2))
+    b = LRO.Factorization(f, 1.0)
+    @test Base.promote_typeof(a, b) == typeof(a)
+    @test Base.promote_typeof(b, a) == typeof(a)
+    @test eltype([a, b]) == typeof(a)
+    @test eltype([b, a]) == typeof(a)
+end
+
 function test_conversion()
     F = reshape([1, 2], 2, 1)
     lowrank = LRO.Factorization(F, [1])