This is a big commit because of a data loss problem. It should be at
least two separate commits (json.c-support and new API)
* eglot.el (eglot-server-programs): Rework docstring.
(eglot-handle-request): Don't take ID param
(eglot-lsp-server): No more initargs.
(eglot--interactive): Return 5 args.
(eglot): Take 5 args.
(eglot-reconnect): Pass 6 args to eglot--connect.
(eglot--dispatch): Remove.
(eglot--connect): Take 6 args. Rework.
(eglot-handle-notification): Change all specializations
to use a non-keyword symbol spec.
(eglot-handle-request): Remove ID param from all
specializations. Don't pass ID to jsonrpc-reply.
(eglot--register-unregister): Don't take JSONRPC-ID arg.
Don't pass ID to jsonrpc-reply.
* jsonrpc-tests.el (returns-3, signals-an--32603-JSONRPC-error)
(times-out, stretching-it-but-works)
(json-el-cant-serialize-this, jsonrpc-connection-ready-p)
(deferred-action-intime, deferred-action-toolate)
(deferred-action-timeout): Pass JSON objects compatible with
json.c
(jsonrpc--test-client, jsonrpc--test-endpoint): New classes
(jsonrpc--with-emacsrpc-fixture): Don't use jsonrpc-connect.
(jsonrpc-connection-ready-p): Update signature.
* jsonrpc.el: Rewrite commentary.
(jsonrpc-connection): Rework class.
(jsonrpc-process-connection): Rework class.
(initialize-instance): New methods..
(jsonrpc--json-read, jsonrpc--json-encode): Reindent.
(jsonrpc-connect): Delete.
(jsonrpc--json-read, jsonrpc--json-encode):
New functions for working with json.c
(jsonrpc--process-filter): Call them.
(jsonrpc--unanswered-request-id): New variable.
(jsonrpc--connection-receive): Use jsonrpc--unanswered-request-id
(jsonrpc-connection-send): Take keyword params to build message
instead of message.
(jsonrpc-notify, jsonrpc--async-request-1): Use new
jsonrpc-connection-send.
(jsonrpc-reply): Simplify.
* eglot-tests.el (rls-watches-files, rls-basic-diagnostics)
(rls-hover-after-edit): Correctly compare using string= and
non-keyword symbols.