What is target-lexicon?

target-lexicon is a small Rust library that helps compilers and related tools understand "target triples", the shorthand strings like x86_64-unknown-linux-gnu that describe what kind of system a piece of software is being built for. Instead of every tool writing its own logic to parse these strings, this library handles it once, cleanly and correctly. A target triple encodes several things: the CPU architecture, the operating system, and sometimes the binary format or other details. Despite the name, these strings often have more than three fields. The library parses that string into a structured format, giving you enums for each field. It also provides handy functions to query details like endianness, pointer width, and binary format directly. You can convert a triple to and from its conventional string representation, and there's even a host() function to describe the machine you're currently running on. This is useful for anyone building developer tooling in Rust that needs to reason about cross-compilation or multiple platforms. If you're writing a build system, a package manager, or a compiler backend, you'll likely need to parse and act on target triples. For instance, rustc and rustup, the Rust compiler and toolchain installer, rely on exactly the triples this library supports. Instead of hardcoding a list of platforms or writing fragile string-matching logic, you get a well-maintained library that covers all the triples those tools currently use. One notable limitation: the library doesn't read JSON target specification files. If you're working with a custom target defined in JSON, you'd extract the "llvm-target" field from that file and pass it here. This keeps the library focused on parsing and querying triple strings rather than becoming a general-purpose target configuration reader.