feat: add discrete saving functionality

Author: AayushSabharwal

Project.toml

@@ -30,6 +30,7 @@ SparseArrays = "2f01184e-e22b-5df5-ae63-d93ebab69eaf"
 Static = "aedffcd0-7271-4cad-89d0-dc628f76c6d3"
 StaticArraysCore = "1e83bf80-4336-4d27-bf5d-d5a4f845583c"
 Statistics = "10745b16-79ce-11e8-11f9-7d13ad32a3b2"
+SymbolicIndexingInterface = "2efcf032-c050-4f8e-a9bb-153293bab1f5"
 Tricks = "410a4b4d-49e4-4fbc-ab6d-cb71b17b3775"
 TruncatedStacktraces = "781d530d-4396-4725-bb49-402e4bee1e77"
 

src/DiffEqBase.jl

@@ -100,6 +100,8 @@ PrecompileTools.@recompile_invalidations begin
 
     import SciMLBase: AbstractDiffEqLinearOperator # deprecation path
 
+    import SymbolicIndexingInterface: parameter_values, current_time
+
     import Tricks
 end
 

src/callbacks.jl

@@ -586,6 +586,7 @@ function apply_callback!(integrator,
             callback.affect_neg!(integrator, event_idx) : callback.affect_neg!(integrator)
         end
     end
+    SciMLBase.save_discrete_parameters_after_callback(integrator.sol, parameter_values(integrator), current_time(integrator))
 
     if integrator.u_modified
         reeval_internals_due_to_modification!(integrator)
@@ -611,6 +612,8 @@ end
         end
         integrator.u_modified = true
         callback.affect!(integrator)
+
+        SciMLBase.save_discrete_parameters_after_callback(integrator.sol, parameter_values(integrator), current_time(integrator))
         if integrator.u_modified
             reeval_internals_due_to_modification!(integrator, false) # continuous_modification=false
         end