diff --git a/src/GroupRings.jl b/src/GroupRings.jl index b4c57ca..63187da 100644 --- a/src/GroupRings.jl +++ b/src/GroupRings.jl @@ -114,10 +114,17 @@ end # ############################################################################### +# sparse storage: + zero(RG::GroupRing, T::Type=Int) = RG(T) one(RG::GroupRing, T::Type=Int) = RG(RG.group(), T) one(RG::GroupRing{R}, T::Type=Int) where {R<:Ring} = RG(one(RG.group()), T) +function (RG::GroupRing)(T::Type=Int) + isdefined(RG, :basis) || throw("Can not coerce without basis of GroupRing") + return GroupRingElem(spzeros(T,length(RG.basis)), RG) +end + function (RG::GroupRing)(i::Int, T::Type=Int) elt = RG(T) elt[RG.group()] = i @@ -130,24 +137,12 @@ function (RG::GroupRing{R})(i::Int, T::Type=Int) where {R<:Ring} return elt end -function (RG::GroupRing)(T::Type=Int) - isdefined(RG, :basis) || throw("Can not coerce without basis of GroupRing") - return GroupRingElem(spzeros(T,length(RG.basis)), RG) -end - function (RG::GroupRing)(g::GroupElem, T::Type=Int) result = RG(T) result[RG.group(g)] = one(T) return result end -function (RG::GroupRing)(x::AbstractVector{T}) where {T<:Number} - length(x) == length(RG.basis) || throw("Can not coerce to $RG: lengths differ") - result = RG(T) - result.coeffs = x - return result -end - function (RG::GroupRing{Gr,T})(V::Vector{T}, S::Type=Int) where {Gr<:Group, T<:GroupElem} res = RG(S) for g in V @@ -156,20 +151,26 @@ function (RG::GroupRing{Gr,T})(V::Vector{T}, S::Type=Int) where {Gr<:Group, T<:G return res end +# keep storage type + +function (RG::GroupRing)(x::AbstractVector{T}) where T + length(x) == length(RG.basis) || throw("Can not coerce to $RG: lengths differ") + return GroupRingElem(x, RG) +end + function (RG::GroupRing)(X::GroupRingElem) RG == parent(X) || throw("Can not coerce!") return RG(X.coeffs) end -function (RG::GroupRing)(X::GroupRingElem, emb::Function) +function (RG::GroupRing)(f::Function, X::GroupRingElem) isdefined(RG, :basis) || throw("Can not coerce without basis of GroupRing") - result = RG(eltype(X.coeffs)) - T = typeof(X.coeffs) - result.coeffs = T(result.coeffs) - for g in parent(X).basis - result[emb(g)] = X[g] + res = RG(zeros(X.coeffs)) + + for g in RG.basis + res[f(g)] = X[g] end - return result + return res end ###############################################################################