Homepage: https://github.com/axelf4/earl
Author: Axel Forsman
Updated:
Erlang distribution protocol implementation
This library implements the Erlang distribution protocol as described in https://www.erlang.org/doc/apps/erts/erl_dist_protocol.html, allowing Emacs to communicate with Erlang VMs as if it were another Erlang node. This is achieved with an Erlang-like process runtime. New processes are created by providing `earl-spawn' with a generator function (see the `generator' package) to run. Scheduling is cooperative, not preemptive---processes must voluntarily give other processes the opportunity to run by calling `earl-yield' or `earl-receive'. Inter-process communication happens solely through asynchronous message passing. The following example (where "!" is a shorthand for `earl-send') illustrates spawning a process that replies once with the number it received plus one: (let ((pid (earl-spawn (iter-make (earl-receive (`(,from . ,i) (! from (1+ i)))))))) (! pid (cons (earl-self) 5)) (earl-receive (i (message "Received %d!" i)))) Erlang terms in external term format, see https://www.erlang.org/doc/apps/erts/erl_ext_dist.html, are convertible to and from Emacs Lisp terms using the functions `earl-read' and `earl-write', as per the table below: Erlang <=> Emacs Lisp --------------------------------- [] / [a | b] nil / (a . b) nil [EXT nil] {a, b} [a b] #{...} #s(hash-table ...) "foo" (?f ?o ?o) <<"foo">> "foo" where "EXT" denotes the value of `earl-tag'. In addition, integers; floats; and other atoms/symbols are converted to their respective counterparts, and Erlang process identifiers and references are translated to opaque ELisp objects. Bitstrings and ports are not yet supported. If a local Erlang VM was started with e.g. "erl -sname arnie", you may connect to it and perform an RPC using: (earl-do (earl-call (earl-rpc (intern (concat "arnie@" (system-name))) 'erlang 'node ())))