{"ast_node_type":"variable","tokens":[{"end":62,"kind":"keyword","start":0,"text":"let"}]}
    let module = ctx.sema.scope(tail_expr.syntax())?.module();
    let (fn_type, tail_expr, builder_edit_pos) = extract_tail(ctx)?;
    let ty = ctx.sema.type_of_expr(&peel_blocks(tail_expr.clone()))?.original();