syntax_data: {"ast_node_type":"variable","tokens":[{"end":35,"kind":"keyword","start":0,"text":"let"}]}
source_snippet:                     let rhs_child =
context_before:                     let PlaceInfo { ty, proj_elem, next_sibling, .. } = self.places[lhs_child];
context_after:                         self.register_place(ty, rhs, proj_elem.expect("child is not a projection"));