Module Ecaml.Ecaml_callback

This module is used to enforce the expected types of registered callbacks.

module Value = Value0

type 'a t

val register : 'a t ‑> f:'a ‑> should_run_holding_async_lock:bool ‑> unit

val attach_async_finalizer : (Value.t ‑> unit) t

attach_async_finalizer is called whenever a Value.t is created, to attach an Async finalizer to the value that will, when the OCaml value is freed, free the Emacs value. The finalizer is an Async finalizer, not an ordinary finalizer, to ensure that it runs in an Async from an Emacs callback.

val dispatch_function : (Function_id.t ‑> Value.t array ‑> Value.t) t

dispatch_function is how Emacs calls from C to OCaml.

val end_of_module_initialization : (unit ‑> unit) t

The C code arranges to call end_of_module_initialization at the end of emacs_module_init, which is what Emacs calls to initialize an Ecaml plugin. This is after all the other top-level OCaml code has run.

val free_function : (Function_id.t ‑> unit) t

free_function function_id is called by Emacs when it garbage collects the sentinel associated with the callback whose id is function_id. This callback does not have an active env, and so is not allowed to call Emacs from OCaml.

val no_active_env : (unit ‑> unit) t

no_active_env is used when the C code detects that OCaml is attempting to call an Emacs function but there is no active env. It prints a message that includes an OCaml backtrace, which may be useful in debugging.