  Compositional and domain generalization present significant challenges in
semantic parsing, even for state-of-the-art semantic parsers based on
pre-trained language models (LMs). In this study, we empirically investigate
improving an LM's generalization in semantic parsing with two simple
techniques: at the token level, we introduce a token preprocessing method to
preserve the semantic boundaries of tokens produced by LM tokenizers; at the
sequence level, we propose to use special tokens to mark the boundaries of
components aligned between input and output. Our experimental results on two
text-to-SQL semantic parsing datasets show that our token preprocessing,
although simple, can substantially improve the LM performance on both types of
generalization, and our component boundary marking method is particularly
helpful for compositional generalization.
