Function serializeASTNode

packages/lang-core/src/parser/serialize.ts:60–110

(node: ASTNode)

// ─── AST node serializer ─────────────────────────────────────────────────────

function serializeASTNode(node: ASTNode): string {
  switch (node.k) {
    case "Str":
      return JSON.stringify(node.v);
    case "Num":
      return String(node.v);
    case "Bool":
      return node.v ? "true" : "false";
    case "Null":
      return "null";
    case "Ph":
      return node.n;
    case "StateRef":
      return node.n; // already includes $ prefix
    case "RuntimeRef":
      return node.n;
    case "Arr":
      return "[" + node.els.map(serializeASTNode).join(", ") + "]";
    case "Obj":
      return "{" + node.entries.map(([k, v]) => `${k}: ${serializeASTNode(v)}`).join(", ") + "}";
    case "BinOp": {
      const left = serializeBinOpChild(node.left, node.op, "left");
      const right = serializeBinOpChild(node.right, node.op, "right");
      return `${left} ${node.op} ${right}`;
    }
    case "UnaryOp":
      return `${node.op}${serializeASTNode(node.operand)}`;
    case "Ternary":
      return `${serializeASTNode(node.cond)} ? ${serializeASTNode(node.then)} : ${serializeASTNode(node.else)}`;
    case "Member":
      return `${serializeASTNode(node.obj)}.${node.field}`;
    case "Index":
      return `${serializeASTNode(node.obj)}[${serializeASTNode(node.index)}]`;
    case "Assign":
      return `${node.target} = ${serializeASTNode(node.value)}`;
    case "Comp": {
      const args = node.args.map(serializeASTNode).join(", ");
      // Builtin (not Action) → @-prefix
      if (isBuiltin(node.name) && node.name !== "Action") {
        return `@${node.name}(${args})`;
      }
      // Action, reserved calls (Query/Mutation), catalog components → no prefix
      return `${node.name}(${args})`;
    }
    // Ref nodes should not appear after materialization, but handle defensively
    case "Ref":
      return node.n;
    default:
      return "null";
  }
}

/** Wrap a BinOp child in parens if its precedence is lower than the parent's. */
function serializeBinOpChild(child: ASTNode, parentOp: string, _side: "left" | "right"): string {