From eff4b89cff4e1b8fcceb23c54cb62ec636ce62fe Mon Sep 17 00:00:00 2001 From: Lukasz Kasprzak Date: Wed, 19 Aug 2026 07:47:30 +0200 Subject: feat(render): per-flavour escaping and RFC 5545 line folding Six flavours: latex, groff, html, xml, ics, none. Markdown, AsciiDoc and plain text map to none deliberately -- their metacharacters are context-dependent and escaping them aggressively produces worse output than not escaping. An unrecognised extension returns None rather than falling back to none: guessing the flavour wrong produces malformed output that looks fine until it does not. Folding backs off to a non-continuation byte, so a fold never splits a UTF-8 sequence -- the failure mode that would corrupt Polish and Latin names in a published feed. --- lib/render/escape.mli | 28 ++++++++++++++++++++++++++++ 1 file changed, 28 insertions(+) create mode 100644 lib/render/escape.mli (limited to 'lib/render/escape.mli') diff --git a/lib/render/escape.mli b/lib/render/escape.mli new file mode 100644 index 0000000..97cf050 --- /dev/null +++ b/lib/render/escape.mli @@ -0,0 +1,28 @@ +(** Per-flavour escaping for the template engine, plus RFC 5545 line folding. + + Knows nothing about calendars. Pure and total: every function is defined on + every string, and none reads the clock, the environment or the filesystem. *) + +(** The six escaping modes. Markdown, AsciiDoc and plain text all use [None_]: + their metacharacter sets are context-dependent, and escaping them + aggressively produces worse output than not escaping at all (spec section 5). + This is a documented limitation of those flavours. *) +type flavour = Latex | Groff | Html | Xml | Ics | None_ + +val all : flavour list +val to_string : flavour -> string +val of_string : string -> flavour option + +(** [of_extension ".tex"] is [Some Latex]. Returns [None] for an unrecognised + extension: the caller must treat that as an error, never as a fallback to + [None_] (spec section 5 -- guessing wrong here produces malformed output + that looks fine until it does not). *) +val of_extension : string -> flavour option + +(** Escape one interpolated value for [flavour]. *) +val apply : flavour -> string -> string + +(** Fold one unfolded content line per RFC 5545 section 3.1: at most 75 octets + per line, continuation lines prefixed with one space, CRLF terminators, + never splitting a UTF-8 sequence. The returned string ends with CRLF. *) +val fold_ics : string -> string -- cgit v1.3