rss.nx

rss.nx -- RSS 2.0 feed builder. Emits valid RSS 2.0 XML (specification: Harvard Berkman Center, 2009). Every feed reader, podcast app, news aggregator, and many static site generators consume RSS. nishi-pages without RSS is half a blog engine. Feed skeleton: <?xml version=\"1.0\" encoding=\"utf-8\"?> <rss version=\"2.0\"> <channel> <title>...</title> <link>...</link> <description>...</description> <language>en</language> <pubDate>Wed, 22 Apr 2026 12:34:56 GMT</pubDate> <item> <title>...</title> <link>...</link> <description>...</description> <pubDate>...</pubDate> <guid>...</guid> </item> ... </channel> </rss> All dates use IMF-fixdate (http_date.nx). Text content is HTML-escaped (html_escape.nx) so the feed can contain '<', '>', '&' safely. This is a stream-builder: caller walks their posts and calls rss_item for each; we don't own the post list. All output appends to a caller-owned buffer with bounds checking. Invariants: R1 Order matters: rss_begin -> rss_item* -> rss_end. R2 Caller supplies HTML-unsafe text; we escape internally. R3 All dates are unix seconds converted to GMT fixdate. R4 Description can contain HTML; we wrap it in CDATA rather