Function evaluateActionCall

packages/lang-core/src/runtime/evaluator.ts:306–364

* Evaluate Action/Run/ToAssistant/OpenUrl Comp nodes into ActionPlan/ActionStep values.

(
  name: string,
  args: ASTNode[],
  context: EvaluationContext,
)

 * Evaluate Action/Run/ToAssistant/OpenUrl Comp nodes into ActionPlan/ActionStep values.
 */
function evaluateActionCall(
  name: string,
  args: ASTNode[],
  context: EvaluationContext,
): ActionPlan | ActionStep | null {
  switch (name) {
    case "Action": {
      // Action([step1, step2, ...]) → ActionPlan
      const stepsArg = args.length > 0 ? evaluate(args[0], context) : [];
      const rawSteps = Array.isArray(stepsArg) ? stepsArg : [];
      const steps: ActionStep[] = rawSteps.filter(
        (s): s is ActionStep => s != null && typeof s === "object" && "type" in s,
      );
      return { steps };
    }
    case "Run": {
      // Run(runtimeRef) → ActionStep { type: "run", statementId, refType }
      if (args.length === 0) return null;
      const refNode = args[0];
      if (refNode.k === "RuntimeRef") {
        return { type: ACTION_STEPS.Run, statementId: refNode.n, refType: refNode.refType };
      }
      // Unresolved Ref — skip (filtered out by Action's step array)
      return null;
    }
    case "ToAssistant": {
      // ToAssistant("message") or ToAssistant("message", "context")
      const message = args.length > 0 ? String(evaluate(args[0], context) ?? "") : "";
      const ctx = args.length > 1 ? String(evaluate(args[1], context) ?? "") : undefined;
      return { type: ACTION_STEPS.ToAssistant, message, context: ctx };
    }
    case "OpenUrl": {
      // OpenUrl("url")
      const url = args.length > 0 ? String(evaluate(args[0], context) ?? "") : "";
      return { type: ACTION_STEPS.OpenUrl, url };
    }
    case "Set": {
      // Set($varName, value) → ActionStep { type: "set", target, valueAST }
      // First arg must be a StateRef (the $variable), second arg is the value expression.
      // valueAST is preserved as-is and evaluated at click time by triggerAction.
      // Loop variables (e.g. t.id from Each) are pre-resolved by Each's substituteRef.
      if (args.length < 2) return null;
      const targetNode = args[0];
      if (targetNode.k !== "StateRef") return null;
      return { type: ACTION_STEPS.Set, target: targetNode.n, valueAST: args[1] };
    }
    case "Reset": {
      // Reset($var1, $var2, ...) → ActionStep { type: "reset", targets: [...] }
      // All args must be StateRef nodes. Restores to declared defaults at runtime.
      const targets = args
        .filter((a): a is ASTNode & { k: "StateRef" } => a.k === "StateRef")
        .map((a) => a.n);
      if (targets.length === 0) return null;
      return { type: ACTION_STEPS.Reset, targets };
    }
    default:
      return null;
  }