syntax_data: {"ast_node_type":"other","tokens":[{"end":82,"kind":"keyword","start":0,"text":".map(|discr_val|"}]}
source_snippet:                     .map(|discr_val| (discr.size.truncate(discr_val), new_block)),
context_before:                     .into_iter()
context_after:                 invalid_discr_block,