Pre-compiles assign expressions

lib/sc/actions/assign_action.ex

@@ -32,33 +32,53 @@ defmodule SC.Actions.AssignAction do
   require Logger
 
   @enforce_keys [:location, :expr]
-  defstruct [:location, :expr, :source_location]
+  defstruct [:location, :expr, :compiled_expr, :source_location]
 
   @type t :: %__MODULE__{
           location: String.t(),
           expr: String.t(),
+          compiled_expr: term() | nil,
           source_location: map() | nil
         }
 
   @doc """
   Create a new AssignAction from parsed attributes.
 
+  The expr is compiled for performance during creation.
+
   ## Examples
 
-      iex> SC.Actions.AssignAction.new("user.name", "'John'")
-      %SC.Actions.AssignAction{location: "user.name", expr: "'John'"}
+      iex> action = SC.Actions.AssignAction.new("user.name", "'John'")
+      iex> action.location
+      "user.name"
+      iex> action.expr
+      "'John'"
+      iex> is_list(action.compiled_expr) 
+      true
 
   """
   @spec new(String.t(), String.t(), map() | nil) :: t()
   def new(location, expr, source_location \\ nil)
       when is_binary(location) and is_binary(expr) do
+    # Pre-compile expression for performance
+    compiled_expr = compile_safe(expr, :expression)
+
     %__MODULE__{
       location: location,
       expr: expr,
+      compiled_expr: compiled_expr,
       source_location: source_location
     }
   end
 
+  # Safely compile expressions, returning nil on error
+  defp compile_safe(expr, _type) do
+    case ValueEvaluator.compile_expression(expr) do
+      {:ok, compiled} -> compiled
+      {:error, _reason} -> nil
+    end
+  end
+
   @doc """
   Execute the assign action by evaluating the expression and assigning to the location.
 
@@ -73,10 +93,12 @@ defmodule SC.Actions.AssignAction do
   def execute(%__MODULE__{} = assign_action, %StateChart{} = state_chart) do
     context = build_evaluation_context(state_chart)
 
+    # Use ValueEvaluator.evaluate_and_assign with pre-compiled expression if available
     case ValueEvaluator.evaluate_and_assign(
            assign_action.location,
            assign_action.expr,
-           context
+           context,
+           assign_action.compiled_expr
          ) do
       {:ok, updated_data_model} ->
         # Update the state chart with the new data model

lib/sc/value_evaluator.ex

@@ -147,13 +147,21 @@ defmodule SC.ValueEvaluator do
   Evaluate an expression and assign its result to a location in the data model.
 
   This combines expression evaluation with location-based assignment.
+  If a pre-compiled expression is provided, it will be used for better performance.
   """
   @spec evaluate_and_assign(String.t(), String.t(), map()) :: {:ok, map()} | {:error, term()}
   def evaluate_and_assign(location_expr, value_expr, context)
       when is_binary(location_expr) and is_binary(value_expr) and is_map(context) do
+    evaluate_and_assign(location_expr, value_expr, context, nil)
+  end
+
+  @spec evaluate_and_assign(String.t(), String.t(), map(), term() | nil) ::
+          {:ok, map()} | {:error, term()}
+  def evaluate_and_assign(location_expr, value_expr, context, compiled_expr)
+      when is_binary(location_expr) and is_binary(value_expr) and is_map(context) do
     with {:ok, path} <- resolve_location(location_expr, context),
-         {:ok, compiled_value} <- compile_expression(value_expr),
-         {:ok, evaluated_value} <- evaluate_value(compiled_value, context),
+         {:ok, evaluated_value} <-
+           evaluate_expression_optimized(value_expr, compiled_expr, context),
          data_model <- extract_data_model(context),
          {:ok, updated_model} <- assign_value(path, evaluated_value, data_model) do
       {:ok, updated_model}
@@ -162,6 +170,37 @@ defmodule SC.ValueEvaluator do
     end
   end
 
+  # Use pre-compiled expression if available, otherwise use the string
+  defp evaluate_expression_optimized(_value_expr, compiled_expr, context)
+       when not is_nil(compiled_expr) do
+    # Pass compiled instructions directly to predicator
+    evaluate_with_predicator(compiled_expr, context)
+  end
+
+  defp evaluate_expression_optimized(value_expr, nil, context) do
+    # Pass string directly to predicator for compilation and evaluation
+    evaluate_with_predicator(value_expr, context)
+  end
+
+  # Evaluate using predicator with proper SCXML context and functions
+  defp evaluate_with_predicator(expression_or_instructions, context) do
+    eval_context =
+      if has_scxml_context?(context) do
+        ConditionEvaluator.build_scxml_context(context)
+      else
+        context
+      end
+
+    scxml_functions = ConditionEvaluator.build_scxml_functions(context)
+
+    case Predicator.evaluate(expression_or_instructions, eval_context, functions: scxml_functions) do
+      {:ok, value} -> {:ok, value}
+      {:error, reason} -> {:error, reason}
+    end
+  rescue
+    error -> {:error, error}
+  end
+
   # Private functions
 
   # Check if context has SCXML-specific keys

test/sc/actions/assign_action_test.exs

@@ -184,5 +184,31 @@ defmodule SC.Actions.AssignActionTest do
 
       assert %StateChart{data_model: %{"counter" => 0, "stateCount" => 1}} = result
     end
+
+    test "pre-compiles expressions during creation for performance" do
+      action = AssignAction.new("user.profile.name", "'John Doe'")
+
+      # Verify that expression is pre-compiled
+      assert not is_nil(action.compiled_expr)
+      assert is_list(action.compiled_expr)
+
+      # Verify original strings are preserved
+      assert action.location == "user.profile.name"
+      assert action.expr == "'John Doe'"
+    end
+
+    test "uses pre-compiled expressions for better performance", %{state_chart: state_chart} do
+      action = AssignAction.new("user.settings.theme", "'dark'")
+
+      # Verify pre-compilation occurred for expression
+      assert not is_nil(action.compiled_expr)
+
+      # Execute should use pre-compiled expressions internally
+      result = AssignAction.execute(action, state_chart)
+
+      # Verify result is correct
+      expected_data = %{"user" => %{"settings" => %{"theme" => "dark"}}}
+      assert %StateChart{data_model: ^expected_data} = result
+    end
   end
 end