Merge pull request #96 from JuliaAlgebra/bl/convert_alg

Conversion of AlgebraElement

Author: kalmarek

src/sparse_coeffs.jl

@@ -120,6 +120,27 @@ function Base.similar(s::SparseCoefficients, ::Type{T} = value_type(s)) where {T
     return SparseCoefficients(collect(s.basis_elements), _similar(s.values, T), s.isless)
 end
 
+function Base.convert(
+    ::Type{SparseCoefficients{K,V,Vh,Vv,L}},
+    s::SparseCoefficients{K,V,Vh,Vv,L},
+) where {K,V,Vh,Vv,L}
+    return s
+end
+
+_collect_if_needed(::Type, v) = v
+_collect_if_needed(::Type{<:AbstractVector}, t::Tuple) = collect(t)
+
+function Base.convert(
+    ::Type{SparseCoefficients{K,V,Vh,Vv,L}},
+    s::SparseCoefficients,
+) where {K,V,Vh,Vv,L}
+    return SparseCoefficients{K,V,Vh,Vv,L}(
+        _collect_if_needed(Vh, s.basis_elements),
+        _collect_if_needed(Vv, s.values),
+        s.isless,
+    )
+end
+
 function map_keys(f::Function, s::SparseCoefficients)
     return SparseCoefficients(map(f, s.basis_elements), s.values, s.isless)
 end

src/types.jl

@@ -146,3 +146,13 @@ function AlgebraElement{T}(X::AlgebraElement) where {T}
     end
     return AlgebraElement(w, parent(X))
 end
+
+function Base.convert(::Type{AlgebraElement{A,T,V}}, a::AlgebraElement{A,T,V}) where {A,T,V}
+    return a
+end
+
+# Useful for instance if `V` is `SparseCoefficients` with `Tuple`
+# and `U` is `SparseCoefficients` with `Vector`
+function Base.convert(::Type{AlgebraElement{A,T,U}}, a::AlgebraElement{A,T,V}) where {A,T,U,V}
+    return AlgebraElement(convert(U, coeffs(a)), parent(a))
+end

test/caching_allocations.jl

@@ -87,6 +87,13 @@ end
         (1,),
     )
     Z = AlgebraElement(z, fRG)
+
+    @test convert(typeof(SA.coeffs(Y)), SA.coeffs(Y)) === SA.coeffs(Y)
+    @test convert(typeof(Y), Y) === Y
+    @test convert(typeof(Y), Z) !== Z
+    @test convert(typeof(Y), Z) isa typeof(Y)
+    @test convert(typeof(Y), Z) == Z
+
     @test _test_op(+, Z, Z) == _test_op(*, 2, Z)
     @test _test_op(+, Z, Z) == _test_op(+, Y, Y)
     @test _test_op(+, Y, Z) == _test_op(+, Y, Y)