Add promotion for ideal (#47)

* Add promotion for ideal

* Fix format

* Add tests

* Add MA to tests

Author: blegat

src/fix.jl

@@ -67,6 +67,12 @@ function Base.convert(
 end
 
 ideal(set::FixedVariablesSet, args...) = set.ideal
+function MA.promote_operation(
+    ::typeof(ideal),
+    ::Type{FixedVariablesSet{V,T,M}},
+) where {V,T,M}
+    return FixedVariablesIdeal{V,T,M}
+end
 MP.variables(set::FixedVariablesSet) = MP.variables(set.ideal)
 function MP.monomial_type(::Type{FixedVariablesSet{V,T,M}}) where {V,T,M}
     return M

src/variety.jl

@@ -116,6 +116,12 @@ function projective_algebraic_set(p::Vector, args...)
 end
 
 ideal(V::AlgebraicSet) = V.I
+function MA.promote_operation(
+    ::typeof(ideal),
+    ::Type{<:AlgebraicSet{T,P,A}},
+) where {T,P,A}
+    return PolynomialIdeal{T,P,A}
+end
 
 MP.variables(V::AlgebraicSet) = MP.variables(V.I)
 MP.monomial_type(::Type{<:AlgebraicSet{T,P}}) where {T,P} = MP.monomial_type(P)

test/Project.toml

@@ -2,6 +2,7 @@
 DynamicPolynomials = "7c1d4256-1411-5781-91ec-d7bc3513ac07"
 LinearAlgebra = "37e2e46d-f89d-539d-b4ee-838fcccc9c8e"
 MultivariatePolynomials = "102ac46a-7ee4-5c85-9060-abc95bfdeaa3"
+MutableArithmetics = "d8a4904e-b15c-11e9-3269-09a3773c0cb0"
 Random = "9a3f8284-a2c9-5f02-9a11-845980a1fd5c"
 SemialgebraicSets = "8e049039-38e8-557d-ae3a-bc521ccf6204"
 Test = "8dfed614-e22c-5e08-85e1-65c5234f0b40"

test/macro.jl

@@ -1,6 +1,7 @@
 module TestMacro
 
 using Test
+import MutableArithmetics as MA
 using SemialgebraicSets
 using MultivariatePolynomials
 
@@ -14,6 +15,14 @@ function _test_polynomial_API(set, vars)
     mono = prod(vars)
     @test @inferred(variables(set)) == variables(mono)
     @test @inferred(monomial_type(typeof(set))) == monomial_type(typeof(mono))
+    V = set
+    if !(V isa AbstractAlgebraicSet)
+        V = algebraic_set(V)
+    end
+    if !(V isa FullSpace)
+        @test typeof(ideal(V)) == MA.promote_operation(ideal, typeof(V))
+    end
+    return
 end
 
 function runtests()