syntax_data: {"ast_node_type":"other","tokens":[{"end":66,"kind":"keyword","start":0,"text":"opt_match_place.map(|(x,"}]}
source_snippet:                     opt_match_place.map(|(x, y)| (x.cloned(), y)),
context_before:                     ArmHasGuard(guard.is_some()),
context_after:                     pattern.span,