perf(styles): parse embedded styles lazily - #1354
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Importing the styles package parsed all embedded style XML files during init, costing about 5.4 ms and 44k allocations before main starts. Parse each style on first lookup instead, keyed by file name, which by convention is the lowercased style name; a new test enforces that invariant and that every embedded style parses. Registry access is now guarded by a mutex, so concurrent use is safer than before. Only the swapoff fallback style is parsed eagerly.
alecthomas
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Aug 18, 2026
alecthomas
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Aug 18, 2026
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Importing the styles package parses all 79 embedded style XML files at init. This parses each style lazily on first lookup instead, keyed by file name, which by convention is the lowercased style name — a new test enforces that invariant and that every embedded style parses. Only the swapoff fallback is parsed eagerly, and the registry is now mutex-guarded, so concurrent use is safer than before.
GODEBUG=inittrace=1Part of a series reducing the cost of importing chroma (lexers + styles + formatters) from ~15.4 ms to ~1.1 ms.