add toplevel arguments to various getters

src/systems/abstractsystem.jl

@@ -622,7 +622,7 @@
 """
     Initial(x)
 
 The `Initial` operator. Used by initializaton to store constant constraints on variables
 of a system. See the documentation section on initialization for more information.
 """
 struct Initial <: Symbolics.Operator end
@@ -1293,10 +1293,10 @@
 
 See also [`ModelingToolkit.get_unknowns`](@ref).
 """
-function unknowns(sys::AbstractSystem)
+function unknowns(sys::AbstractSystem; toplevel = false)
     sts = get_unknowns(sys)
     systems = get_systems(sys)
-    nonunique_unknowns = if isempty(systems)
+    nonunique_unknowns = if toplevel || isempty(systems)
         sts
     else
         system_unknowns = reduce(vcat, namespace_variables.(systems))
@@ -1320,7 +1320,7 @@
 
 See also [`@parameters`](@ref) and [`ModelingToolkit.get_ps`](@ref).
 """
-function parameters(sys::AbstractSystem; initial_parameters = false)
+function parameters(sys::AbstractSystem; initial_parameters = false, toplevel = false)
     ps = get_ps(sys)
     if ps == SciMLBase.NullParameters()
         return []
@@ -1329,8 +1329,8 @@
         ps = first.(ps)
     end
     systems = get_systems(sys)
-    result = unique(isempty(systems) ? ps :
-                    [ps; reduce(vcat, namespace_parameters.(systems))])
+    result = unique(toplevel || isempty(systems) ?
+                    ps : [ps; reduce(vcat, namespace_parameters.(systems))])
     if !initial_parameters
         if is_time_dependent(sys)
             # time-dependent systems have `Initial` parameters for all their
@@ -1490,8 +1490,9 @@
     isempty(systems) ? ctrls : [ctrls; reduce(vcat, namespace_controls.(systems))]
 end
 
-function observed(sys::AbstractSystem)
+function observed(sys::AbstractSystem; toplevel = false)
     obs = get_observed(sys)
+    toplevel && return obs
     systems = get_systems(sys)
     [obs;
      reduce(vcat,
@@ -1510,7 +1511,7 @@
 
 See also [`initialization_equations`](@ref), [`parameter_dependencies`](@ref) and [`ModelingToolkit.get_defaults`](@ref).
 """
-function defaults(sys::AbstractSystem)
+function defaults(sys::AbstractSystem; toplevel = false)
     systems = get_systems(sys)
     defs = get_defaults(sys)
     # `mapfoldr` is really important!!! We should prefer the base model for
@@ -1519,7 +1520,8 @@
     # `compose(ODESystem(...; defaults=defs), ...)`
     #
     # Thus, right associativity is required and crucial for correctness.
-    isempty(systems) ? defs : mapfoldr(namespace_defaults, merge, systems; init = defs)
+    (toplevel ||isempty(systems)) ?
+        defs : mapfoldr(namespace_defaults, merge, systems; init = defs)
 end
 
 function defaults_and_guesses(sys::AbstractSystem)
@@ -1549,10 +1551,10 @@
 
 See also [`full_equations`](@ref) and [`ModelingToolkit.get_eqs`](@ref).
 """
-function equations(sys::AbstractSystem)
+function equations(sys::AbstractSystem; toplevel = false)
     eqs = get_eqs(sys)
     systems = get_systems(sys)
-    if isempty(systems)
+    if toplevel || isempty(systems)
         return eqs
     else
         eqs = Equation[eqs;

src/systems/callbacks.jl

@@ -94,17 +94,17 @@ A [`ContinuousCallback`](@ref SciMLBase.ContinuousCallback) specified symbolical
 as well as the positive-edge `affect` and negative-edge `affect_neg` that apply when *any* of `eq` are satisfied.
 By default `affect_neg = affect`; to only get rising edges specify `affect_neg = nothing`.
 
-Assume without loss of generality that the equation is of the form `c(u,p,t) ~ 0`; we denote the integrator state as `i.u`. 
+Assume without loss of generality that the equation is of the form `c(u,p,t) ~ 0`; we denote the integrator state as `i.u`.
 For compactness, we define `prev_sign = sign(c(u[t-1], p[t-1], t-1))` and `cur_sign = sign(c(u[t], p[t], t))`.
-A condition edge will be detected and the callback will be invoked iff `prev_sign * cur_sign <= 0`. 
+A condition edge will be detected and the callback will be invoked iff `prev_sign * cur_sign <= 0`.
 The positive edge `affect` will be triggered iff an edge is detected and if `prev_sign < 0`; similarly, `affect_neg` will be
-triggered iff an edge is detected and `prev_sign > 0`. 
+triggered iff an edge is detected and `prev_sign > 0`.
 
-Inter-sample condition activation is not guaranteed; for example if we use the dirac delta function as `c` to insert a 
+Inter-sample condition activation is not guaranteed; for example if we use the dirac delta function as `c` to insert a
 sharp discontinuity between integrator steps (which in this example would not normally be identified by adaptivity) then the condition is not
 guaranteed to be triggered.
 
-Once detected the integrator will "wind back" through a root-finding process to identify the point when the condition became active; the method used 
+Once detected the integrator will "wind back" through a root-finding process to identify the point when the condition became active; the method used
 is specified by `rootfind` from [`SciMLBase.RootfindOpt`](@ref). If we denote the time when the condition becomes active as `tc`,
 the value in the integrator after windback will be:
 * `u[tc-epsilon], p[tc-epsilon], tc` if `LeftRootFind` is used,
@@ -116,7 +116,7 @@ it passed through 0.
 
 Multiple callbacks in the same system with different `rootfind` operations will be grouped
 by their `rootfind` value into separate VectorContinuousCallbacks in the enumeration order of `SciMLBase.RootfindOpt`. This may cause some callbacks to not fire if several become
-active at the same instant. See the `SciMLBase` documentation for more information on the semantic rules. 
+active at the same instant. See the `SciMLBase` documentation for more information on the semantic rules.
 
 Affects (i.e. `affect` and `affect_neg`) can be specified as either:
 * A list of equations that should be applied when the callback is triggered (e.g. `x ~ 3, y ~ 7`) which must be of the form `unknown ~ observed value` where each `unknown` appears only once. Equations will be applied in the order that they appear in the vector; parameters and state updates will become immediately visible to following equations.
@@ -327,14 +327,15 @@ The `SymbolicContinuousCallback`s in the returned vector are structs with two fi
 `affect` which correspond to the first and second elements of a `Pair` used to define an event, i.e.
 `eqs => affect`.
 """
-function continuous_events(sys::AbstractSystem)
-    obs = get_continuous_events(sys)
-    filter(!isempty, obs)
+function continuous_events(sys::AbstractSystem; toplevel = false)
+    cbs = get_continuous_events(sys)
+    filter(!isempty, cbs)
+    toplevel && return cbs
 
     systems = get_systems(sys)
-    cbs = [obs;
+    cbs = [cbs;
            reduce(vcat,
-               (map(o -> namespace_callback(o, s), continuous_events(s))
+               (map(cb -> namespace_callback(cb, s), continuous_events(s))
                for s in systems),
                init = SymbolicContinuousCallback[])]
     filter(!isempty, cbs)
@@ -482,10 +483,11 @@ The `SymbolicDiscreteCallback`s in the returned vector are structs with two fiel
 `affect` which correspond to the first and second elements of a `Pair` used to define an event, i.e.
 `condition => affect`.
 """
-function discrete_events(sys::AbstractSystem)
-    obs = get_discrete_events(sys)
+function discrete_events(sys::AbstractSystem; toplevel = false)
+    cbs = get_discrete_events(sys)
+    toplevel && return cbs
     systems = get_systems(sys)
-    cbs = [obs;
+    cbs = [cbs;
            reduce(vcat,
                (map(o -> namespace_callback(o, s), discrete_events(s)) for s in systems),
                init = SymbolicDiscreteCallback[])]
@@ -688,7 +690,7 @@ function generate_rootfinding_callback(sys::AbstractTimeDependentSystem,
     generate_rootfinding_callback(cbs, sys, dvs, ps; kwargs...)
 end
 """
-Generate a single rootfinding callback; this happens if there is only one equation in `cbs` passed to 
+Generate a single rootfinding callback; this happens if there is only one equation in `cbs` passed to
 generate_rootfinding_callback and thus we can produce a ContinuousCallback instead of a VectorContinuousCallback.
 """
 function generate_single_rootfinding_callback(