yagni: Get rid of unused temporal structure trait logic

Author: lassepe

src/TrajectoryGamesBase.jl

@@ -9,18 +9,7 @@ using GeometryBasics: GeometryBasics
 using Polyhedra: Polyhedra
 
 include("dynamics.jl")
-export AbstractTemporalStructureTrait,
-    control_bounds,
-    control_dim,
-    get_constraints_from_box_bounds,
-    horizon,
-    num_players,
-    rollout,
-    state_bounds,
-    state_dim,
-    temporal_structure_trait,
-    TimeInvariant,
-    TimeVarying
+export control_bounds, control_dim, get_constraints_from_box_bounds, horizon, num_players, rollout, state_bounds, state_dim
 
 include("product_dynamics.jl")
 export ProductDynamics

src/dynamics.jl

@@ -1,15 +1,3 @@
-abstract type AbstractTemporalStructureTrait end
-struct TimeVarying <: AbstractTemporalStructureTrait end
-struct TimeInvariant <: AbstractTemporalStructureTrait end
-
-"""
-    temporal_structure_trait(object)
-
-Returns an `AbstractTemporalStructureTrait` to signal if this object (e.g. strategy or dynamics) is
-time varying or not.
-"""
-function temporal_structure_trait end
-
 """
     dynamics(state, controls[, t, context]).
 

src/linear_dynamics.jl

@@ -14,19 +14,17 @@ Base.@kwdef struct LinearDynamics{TA,TB,TSB,TCB} <: AbstractDynamics
     control_bounds::TCB = (; lb = fill(-Inf, size(first(B), 2)), ub = fill(Inf, size(first(B), 2)))
 end
 
-function LinearDynamics(dynamics::ProductDynamics{<:AbstractVector{<:LinearDynamics}})
-    (; A, B) = _block_diagonalize(
-        temporal_structure_trait(dynamics),
-        dynamics.subsystems,
-        horizon(dynamics),
-    )
+function LinearDynamics(
+    dynamics::ProductDynamics{<:AbstractVector{<:LinearDynamics{<:Fill,<:Fill}}},
+)
+    (; A, B) = _block_diagonalize(dynamics.subsystems, horizon(dynamics))
     sb = state_bounds(dynamics)
     cb = control_bounds(dynamics)
 
     LinearDynamics(; A, B, state_bounds = sb, control_bounds = cb)
 end
 
-function _block_diagonalize(::TimeInvariant, linear_subsystems, horizon)
+function _block_diagonalize(linear_subsystems, horizon)
     A = Fill(blockdiag([sparse(sub.A.value) for sub in linear_subsystems]...), horizon)
 
     B = let
@@ -39,14 +37,6 @@ function _block_diagonalize(::TimeInvariant, linear_subsystems, horizon)
     (; A, B)
 end
 
-function TrajectoryGamesBase.temporal_structure_trait(::LinearDynamics{<:Fill,<:Fill})
-    TimeInvariant()
-end
-
-function TrajectoryGamesBase.temporal_structure_trait(::LinearDynamics)
-    TimeVarying()
-end
-
 function time_invariant_linear_dynamics(; A, B, horizon = ∞, bounds...)
     LinearDynamics(; A = Fill(A, horizon), B = Fill(B, horizon), bounds...)
 end
@@ -55,9 +45,7 @@ function (sys::LinearDynamics)(x, u, t::Int, ::Any = nothing)
     sys.A[t] * x + sys.B[t] * u
 end
 
-function (sys::LinearDynamics)(x, u, ::Nothing = nothing, ::Any = nothing)
-    temporal_structure_trait(sys) isa TimeInvariant ||
-        error("Only time-invariant systems can ommit the `t` argument.")
+function (sys::LinearDynamics{<:Fill,<:Fill})(x, u, ::Nothing = nothing, ::Any = nothing)
     sys.A.value * x + sys.B.value * u
 end
 

src/product_dynamics.jl

@@ -69,10 +69,3 @@ end
 function horizon(dynamics::ProductDynamics)
     horizon(first(dynamics.subsystems))
 end
-
-function temporal_structure_trait(dynamics::ProductDynamics)
-    if all(sub -> temporal_structure_trait(sub) isa TimeInvariant, dynamics.subsystems)
-        return TimeInvariant()
-    end
-    TimeVarying()
-end

test/runtests.jl

@@ -114,9 +114,6 @@ end # Mock module
                 @test control_dim(linear_dynamics) == control_dim(game.dynamics) == 4
                 @test control_dim(linear_dynamics, 1) == control_dim(game.dynamics, 1) == 2
                 @test num_players(linear_dynamics) == num_players(game.dynamics) == 2
-                @test temporal_structure_trait(linear_dynamics) ==
-                      temporal_structure_trait(game.dynamics) ==
-                      TimeInvariant()
             end
 
             @testset "cost" begin