syntax_data: {"ast_node_type":"other","tokens":[{"end":78,"kind":"keyword","start":0,"text":"Bound(debruijn,"}]}
source_snippet:             Bound(debruijn, var) => crate::debug_bound_var(f, *debruijn, var),
context_before:             Infer(var) => write!(f, "{var:?}"),
context_after:             Placeholder(placeholder) => write!(f, "{placeholder:?}"),