syntax_data: {"ast_node_type":"other","tokens":[{"end":96,"kind":"keyword","start":0,"text":"scrut.span.find_ancestor_in_same_ctxt(expr_span).and_then(|scrut_span|"}]}
source_snippet:                         scrut.span.find_ancestor_in_same_ctxt(expr_span).and_then(|scrut_span| {
context_before:                         // stashing the span of the braces somewhere (like in the match source).
context_after:                             let sm = self.tcx.sess.source_map();