syntax_data: {"ast_node_type":"variable","tokens":[{"end":23,"kind":"keyword","start":0,"text":"let"}]}
source_snippet:     let os = match os {
context_before:     // https://github.com/llvm/llvm-project/blob/llvmorg-18.1.8/llvm/lib/TargetParser/Triple.cpp#L236-L282
context_after:         "macos" => "macosx",