PADA: Example-based Prompt Learning for on-the-fly Adaptation to Unseen Domains Eyal Ben-David author Nadav Oved author Roi Reichart author 2022 text journal article Transactions of the Association for Computational Linguistics continuing MIT Press Cambridge, MA periodical academic journal ben-david-etal-2022-pada 10.1162/tacl_a_00468 https://aclanthology.org/2022.tacl-1.24/ 2022 10 414 433