syntax_data: {"ast_node_type":"variable","tokens":[{"end":54,"kind":"keyword","start":0,"text":"let"}]}
source_snippet:                         let (then_block, else_block) =
context_before:                         // Lower the condition, and have it branch into `then` and `else` blocks.
context_after:                             this.in_if_then_scope(condition_scope, then_span, |this| {