Function evaluateLazyBuiltin

packages/lang-core/src/runtime/evaluator.ts:447–483

* Each(array, varName, template) — evaluate template once per array item. * varName is user-defined (e.g. `issue`, `ticket`) — no $ prefix collision. * * Before evaluation, substitutes all Ref(varName) in the template with the * current item's literal value. This ensures deferred expressions (li

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

 * Action/Set steps) capture concrete values instead of dangling loop refs.
 */
function evaluateLazyBuiltin(
  name: string,
  args: ASTNode[],
  context: EvaluationContext,
  schemaCtx?: SchemaContext,
): unknown {
  if (name === "Each") {
    if (args.length < 3) return [];
    const arr = evaluate(args[0], context);
    if (!Array.isArray(arr)) return [];

    const varName =
      args[1].k === "Ref" ? args[1].n : args[1].k === "Str" ? (args[1] as any).v : null;
    if (!varName) return [];
    const template = args[2];

    return arr.map((item, _idx) => {
      // Pre-substitute loop variable refs with concrete values in the template AST.
      // This captures the item for deferred expressions (Action steps evaluated at click time).
      const substituted = substituteRef(template, varName, item);
      const childCtx: EvaluationContext = {
        ...context,
        resolveRef: (refName: string) => {
          if (refName === varName) return item;
          return context.resolveRef(refName);
        },
      };
      const result = evaluate(substituted, childCtx, schemaCtx);
      // If schema context is available and result is an ElementNode, evaluate its props
      if (schemaCtx && isElementNode(result)) {
        return evaluateElementInline(result as ElementNode, childCtx, schemaCtx);
      }
      return result;
    });
  }
  return null;
}