`GeometricIntegrators` and `EulerLagrange` both export `HamiltonianSystem`

[benedict-96]

Perhaps HamiltonianSystem should be defined in https://github.com/JuliaGNI/GeometricIntegratorsBase.jl and then imported by GeometricIntegrators and EulerLagrange so that we don't have the conflict when using both packages?

(issue was raised by @ZeyuanLee)

[ZeyuanLee]

Get the problem when include using GeometricIntegrators and using EulerLagrange in a problem module. Remove using GeometricIntegrators could work, but both packages do export HamiltonianSystem

[michakraus]

Indeed GeometricIntegrators.jl should not export HamiltonianSystem. I will look into this. This definitely should not be defined in GeometricIntegratorsBase.jl.

EDIT:

I cannot see any HamiltonianSystem in GeometricIntegrators.jl. Are you sure this is the cause of whatever error you observed?

[michakraus]

GeometricBase.jl defines HamiltonianSystem, LagrangianSystem, etc.:

abstract type AbstractSystem end

abstract type DynamicalSystem <: AbstractSystem end
abstract type LagrangianSystem <: DynamicalSystem end
abstract type HamiltonianSystem <: DynamicalSystem end

struct RegularLagrangianSystem <: LagrangianSystem end
struct DegenerateLagrangianSystem <: LagrangianSystem end

struct CanonicalHamiltonianSystem <: HamiltonianSystem end
struct NoncanonicalHamiltonianSystem <: HamiltonianSystem end
struct PoissonSystem <: HamiltonianSystem end

I doubt, though, that this is currently used anywhere...