abm-parameters-refactor.patch

diff --git a/R/abm.R b/R/abm.R
index abc1234..def5678 100644
--- a/R/abm.R
+++ b/R/abm.R
@@
 AgentBasedModel <- R6::R6Class(
   "AgentBasedModel",
   private = list(
-    .parameters = NULL
+    .parameters = NULL,  # deprecated: prefer .parameters_instance
+    .parameters_instance = NULL
   ),
   
   public = list(
     initialize = function(parameters) {
-      if (!inherits(parameters, "ModelParameters")) stop("parameters must be a ModelParameters instance")
-      private$.parameters <- parameters$as_list()
+      if (!inherits(parameters, "ModelParameters")) {
+        stop("parameters must be a ModelParameters instance")
+      }
+      private$.parameters_instance <- parameters
+      private$.parameters <- parameters$as_list()  # cached list for backward compatibility
       # other initialization code...
     },
     
     get_parameters = function() {
-      return (private$.parameters)
+      return (private$.parameters_instance)
     },
     
     # other methods...
   )
 )
 
diff --git a/tests/testthat/test-abm.R b/tests/testthat/test-abm.R
index 9876543..fedcba9 100644
--- a/tests/testthat/test-abm.R
+++ b/tests/testthat/test-abm.R
@@
 test_that("AgentBasedModel parameters include adoption_rate", {
   mps <- make_model_parameters(n_agents = 10, adoption_rate = 1.0, learning_strategy = contagion_learning_strategy)
   abm <- make_abm(mps)
-  all_params <- abm$get_parameters()
-  expect_true("adoption_rate" %in% names(all_params))
+  all_params <- abm$get_parameters()$as_list()
+  expect_true("adoption_rate" %in% names(all_params))
 })
+
+test_that("get_parameters returns ModelParameters instance", {
+  mps <- make_model_parameters(n_agents = 10, adoption_rate = 1.0, learning_strategy = contagion_learning_strategy)
+  abm <- make_abm(mps)
+  expect_true(inherits(abm$get_parameters(), "ModelParameters"))
+  
+  param_list <- abm$get_parameters()$as_list()
+  expect_true("adoption_rate" %in% names(param_list))
+})