`*[TERM]: expansion` on its own line, PHP Markdown Extra's form, and every
whole-word use in the document becomes <abbr title="…">.
A transformer rather than an inline parser, because a definition may appear
after the use it explains and a parser only ever sees what it has already read.
A block parser rather than a pattern found later, because the line has to stop
being content — an author would notice that going wrong before anything else.
Whole-word matching is the part that would have bitten: without it a definition
of HTML quietly rewrites HTMLish and xHTML too, so both have cases. Code spans,
autolinks, raw HTML and an already-expanded term are skipped, the longest
definition wins where two could match, and the expansion is escaped into the
attribute so a quoted phrase cannot end it.
Definitions are document-scoped. A term defined in a page does not reach an
included fragment, which is parsed on its own bytes exactly as footnotes are —
stated in content-model.md rather than left to be discovered.
The nesting gate caught firstMatch four levels deep; the inner search is its own
function now, which reads better than it did before the warning.
core 2794/2800, ext 1483/2000, 34 gates green, 0 warnings.
Claude Opus 5andbdeshi
661fb469e8