From cfc641a9bb97c94e5993f895a8bcdf24214adc83 Mon Sep 17 00:00:00 2001 From: Marcos Magueta Date: Mon, 5 Oct 2026 22:40:22 -0300 Subject: journal for the website --- lib/protocols/Journal.mli | 48 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 48 insertions(+) create mode 100644 lib/protocols/Journal.mli (limited to 'lib/protocols/Journal.mli') diff --git a/lib/protocols/Journal.mli b/lib/protocols/Journal.mli new file mode 100644 index 0000000..5f2e760 --- /dev/null +++ b/lib/protocols/Journal.mli @@ -0,0 +1,48 @@ +(** a directory that keeps its history. Every change to its bindings is + a commit: one or more names bound again together, numbered, with a + snapshot of every binding as it stood afterwards. Guards are shown a + commit before it lands and may refuse it; observers are told of it + after. *) +type t + +(** bind [name] to [replacement], or unbind it when [None], provided it + is still bound to [expected]. *) +type change = {name: string; expected: Handle.t option; replacement: Handle.t option} + +(** [snapshot] is a directory of the bindings as of the commit. *) +type commit = {number: int; snapshot: Handle.t; changed: string list} + +(** what a guard is shown: the commit the proposal would follow and the + commit it would be. *) +type proposal = {previous: commit; proposed: commit} + +type guard = proposal -> (unit, Concepts.Condition.condition) result +type observer = commit -> unit + +class type implementation = object + (** [Ok None] when a name was no longer bound to what was expected; + [Error] when a guard refused. Either way nothing changes. *) + method commit : change list -> (commit option, Concepts.Condition.condition) result + + method head : commit + + (** every commit, the oldest first. *) + method history : commit list + + (** install, replace or remove the guard or observer of that name. *) + method guard : string -> guard option -> unit + + method observe : string -> observer option -> unit +end + +val make : #implementation -> Handle.protocol +val from : Handle.t -> t Handle.interface option +val require : Handle.t -> (t Handle.interface, Concepts.Condition.condition) result + +val commit : + t Handle.interface -> change list -> (commit option, Concepts.Condition.condition) result + +val head : t Handle.interface -> commit +val history : t Handle.interface -> commit list +val guard : t Handle.interface -> string -> guard option -> unit +val observe : t Handle.interface -> string -> observer option -> unit -- cgit v1.2.3