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+(** A deliberately logic-less template engine (spec section 5).
+
+ A template is DATA, never a program: placeholders, sections, inverted
+ sections and comments, and nothing else. There are no partials, no lambdas,
+ no expression evaluation, no arithmetic, and no filesystem or process
+ access. There is deliberately no "raw" or triple-brace form -- a template
+ cannot opt out of its flavour's escaping.
+
+ Anything a calendar needs that this cannot express (a month grid's leading
+ blanks, week bucketing) is computed in {!View} and handed in as data. That
+ division is the design, not a workaround. *)
+
+(** What a template can be rendered against. *)
+type value =
+ | Str of string
+ | Bool of bool
+ | List of value list
+ | Obj of (string * value) list
+
+type node =
+ | Text of string
+ | Var of string list (** dotted path, e.g. ["name"; "la"] *)
+ | Section of string list * node list
+ | Inverted of string list * node list
+
+(** Never raises; a malformed template is an [Error] with a human-readable
+ reason, because the template is user input. *)
+val parse : string -> (node list, string) result
+
+(** Render against a value. Escaping is applied to every interpolated value and
+ NEVER to the template's own literal text, which is the author's markup.
+ A missing key renders as the empty string -- the one deliberate silence, so
+ that a template survives a rite that does not set every optional field. *)
+val render : flavour:Escape.flavour -> node list -> value -> string
+
+(** [parse] then [render]. *)
+val render_string : flavour:Escape.flavour -> string -> value -> (string, string) result