Introduce fallbacks for AbstractManifoldPoints and Vectors (#89)

* Introduce default fallbacks for manifold point and tangent vector types, especially broadcasting to be passed on to the .value field
* forwarding macros

Co-authored-by: Mateusz Baran <[email protected]>

Project.toml

@@ -1,7 +1,7 @@
 name = "ManifoldsBase"
 uuid = "3362f125-f0bb-47a3-aa74-596ffd7ef2fb"
 authors = ["Seth Axen <[email protected]>", "Mateusz Baran <[email protected]>", "Ronny Bergmann <[email protected]>", "Antoine Levitt <[email protected]>"]
-version = "0.12.9"
+version = "0.12.10"
 
 [deps]
 LinearAlgebra = "37e2e46d-f89d-539d-b4ee-838fcccc9c8e"

src/ManifoldsBase.jl

@@ -15,7 +15,8 @@ import Base:
     show,
     +,
     -,
-    *
+    *,
+    ==
 import LinearAlgebra: dot, norm, det, cross, I, UniformScaling, Diagonal
 
 import Markdown: @doc_str
@@ -62,6 +63,7 @@ allocate(a::AbstractArray{<:AbstractArray}, T::Type) = map(t -> allocate(t, T),
 allocate(a::NTuple{N,AbstractArray} where {N}) = map(allocate, a)
 allocate(a::NTuple{N,AbstractArray} where {N}, T::Type) = map(t -> allocate(t, T), a)
 
+
 """
     allocate_result(M::AbstractManifold, f, x...)
 
@@ -100,7 +102,6 @@ Compute the angle between tangent vectors `X` and `Y` at point `p` from the
 function angle(M::AbstractManifold, p, X, Y)
     return acos(real(inner(M, p, X, Y)) / norm(M, p, X) / norm(M, p, Y))
 end
-
 """
     base_manifold(M::AbstractManifold, depth = Val(-1))
 
@@ -531,7 +532,7 @@ The size of an array representing a point on [`AbstractManifold`](@ref) `M`.
 Returns `nothing` by default indicating that points are not represented using an
 `AbstractArray`.
 """
-function representation_size(M::AbstractManifold)
+function representation_size(::AbstractManifold)
     return nothing
 end
 
@@ -569,6 +570,7 @@ include("vector_transport.jl")
 include("DecoratorManifold.jl")
 include("bases.jl")
 include("vector_spaces.jl")
+include("point_vector_fallbacks.jl")
 include("ValidationManifold.jl")
 include("EmbeddedManifold.jl")
 include("DefaultManifold.jl")

src/ValidationManifold.jl

@@ -57,26 +57,9 @@ This distinguished the value from [`ValidationMPoint`](@ref)s vectors of other t
 """
 const ValidationCoTVector = ValidationFibreVector{CotangentSpaceType}
 
+@eval @manifold_vector_forwards ValidationFibreVector{TType} TType value
 
-function (+)(X::ValidationFibreVector{TType}, Y::ValidationFibreVector{TType}) where {TType}
-    return ValidationFibreVector{TType}(X.value + Y.value)
-end
-function (-)(X::ValidationFibreVector{TType}, Y::ValidationFibreVector{TType}) where {TType}
-    return ValidationFibreVector{TType}(X.value - Y.value)
-end
-(-)(X::ValidationFibreVector{TType}) where {TType} = ValidationFibreVector{TType}(-X.value)
-function (*)(a::Number, X::ValidationFibreVector{TType}) where {TType}
-    return ValidationFibreVector{TType}(a * X.value)
-end
-
-allocate(p::ValidationMPoint) = ValidationMPoint(allocate(p.value))
-allocate(p::ValidationMPoint, ::Type{T}) where {T} = ValidationMPoint(allocate(p.value, T))
-function allocate(X::ValidationFibreVector{TType}) where {TType}
-    return ValidationFibreVector{TType}(allocate(X.value))
-end
-function allocate(X::ValidationFibreVector{TType}, ::Type{T}) where {TType,T}
-    return ValidationFibreVector{TType}(allocate(X.value, T))
-end
+@eval @manifold_element_forwards ValidationMPoint value
 
 """
     array_value(p)
@@ -422,9 +405,7 @@ function mid_point!(M::ValidationManifold, q, p1, p2; kwargs...)
 end
 
 number_eltype(::Type{ValidationMPoint{V}}) where {V} = number_eltype(V)
-number_eltype(p::ValidationMPoint) = number_eltype(p.value)
 number_eltype(::Type{ValidationFibreVector{TType,V}}) where {TType,V} = number_eltype(V)
-number_eltype(X::ValidationFibreVector) = number_eltype(X.value)
 
 function project!(M::ValidationManifold, Y, p, X; kwargs...)
     is_point(M, p, true; kwargs...)
@@ -433,15 +414,6 @@ function project!(M::ValidationManifold, Y, p, X; kwargs...)
     return Y
 end
 
-similar(p::ValidationMPoint) = ValidationMPoint(similar(p.value))
-similar(p::ValidationMPoint, ::Type{T}) where {T} = ValidationMPoint(similar(p.value, T))
-function similar(X::ValidationFibreVector{TType}) where {TType}
-    return ValidationFibreVector{TType}(similar(X.value))
-end
-function similar(X::ValidationFibreVector{TType}, ::Type{T}) where {TType,T}
-    return ValidationFibreVector{TType}(similar(X.value, T))
-end
-
 function vector_transport_along!(
     M::ValidationManifold,
     Y,

src/bases.jl

@@ -285,6 +285,13 @@ const DISAMBIGUATION_COTANGENT_BASIS_TYPES = [
     DefaultOrthogonalBasis{<:Any,CotangentSpaceType},
 ]
 
+"""
+    allocate_coordinates(M::AbstractManifold, p, T, n::Int)
+
+Allocate vector of coordinates of length `n` of type `T` of a vector at point `p`
+on manifold `M`.
+"""
+allocate_coordinates(M::AbstractManifold, p, T, n::Int) = allocate(p, T, n)
 
 function allocate_result(
     M::AbstractManifold,
@@ -294,7 +301,7 @@ function allocate_result(
     B::AbstractBasis,
 )
     T = allocate_result_type(M, f, (p, X))
-    return allocate(p, T, number_of_coordinates(M, B))
+    return allocate_coordinates(M, p, T, number_of_coordinates(M, B))
 end
 
 function allocate_result(
@@ -305,7 +312,7 @@ function allocate_result(
     B::CachedBasis,
 )
     T = allocate_result_type(M, f, (p, X))
-    return allocate(p, T, number_of_coordinates(M, B))
+    return allocate_coordinates(M, p, T, number_of_coordinates(M, B))
 end
 
 @inline function allocate_result_type(

src/maintypes.jl

@@ -23,7 +23,13 @@ abstract type AbstractManifold{𝔽} end
 
 Type for a point on a manifold. While a [`AbstractManifold`](@ref) does not necessarily require this
 type, for example when it is implemented for `Vector`s or `Matrix` type elements, this type
-can be used for more complicated representations, semantic verification, or even dispatch
-for different representations of points on a manifold.
+can be used either
+* for more complicated representations,
+* semantic verification, or
+* even dispatch for different representations of points on a manifold.
+
+Since semantic verification and different representations usually might still only store a
+matrix internally, it is possible to use [`@manifold_element_forwards`](@ref) and
+[`@default_manifold_fallbacks`](@ref) to reduce implementation overhead.
 """
 abstract type AbstractManifoldPoint end