feat: allow namespacing statemachine equations

Author: AayushSabharwal

src/ModelingToolkit.jl

@@ -69,7 +69,7 @@ using Symbolics: _parse_vars, value, @derivatives, get_variables,
                  NAMESPACE_SEPARATOR, set_scalar_metadata, setdefaultval,
                  initial_state, transition, activeState, entry, hasnode,
                  ticksInState, timeInState, fixpoint_sub, fast_substitute,
-                 CallWithMetadata, CallWithParent
+                 CallWithMetadata, CallWithParent, Transition, InitialState
 const NAMESPACE_SEPARATOR_SYMBOL = Symbol(NAMESPACE_SEPARATOR)
 import Symbolics: rename, get_variables!, _solve, hessian_sparsity,
                   jacobian_sparsity, isaffine, islinear, _iszero, _isone,

src/systems/abstractsystem.jl

@@ -1390,6 +1390,26 @@ function namespace_expr(
         O
     end
 end
+
+function namespace_expr(
+        O::Transition, sys, n = nameof(sys); ivs = independent_variables(sys))
+    return Transition(
+        O.from === nothing ? O.from : renamespace(sys, O.from),
+        O.to === nothing ? O.to : renamespace(sys, O.to),
+        O.cond === nothing ? O.cond : namespace_expr(O.cond, sys),
+        O.immediate, O.reset, O.synchronize, O.priority
+    )
+end
+
+function namespace_expr(
+        O::InitialState, sys, n = nameof(sys); ivs = independent_variables(sys))
+    return InitialState(O.s === nothing ? O.s : renamespace(sys, O.s))
+end
+
+function namespace_expr(O::StateMachineOperator, sys, n = nameof(sys); kwargs...)
+    error("Unhandled state machine operator")
+end
+
 _nonum(@nospecialize x) = x isa Num ? x.val : x
 
 """