Migrating from SLY

Migrating from Common Lisp SLY to SLYNET

SLYNET deliberately borrows useful SLY/SLYNK workflow and wire concepts, but it is a Janet development environment rather than a Common Lisp implementation of SLYNK. Migration therefore means preserving familiar editor habits where Janet can support them and learning the places where a literal SLY semantic claim would be false.

The shortest migration path

1. Install Janet and add SLYNET’s emacs/ directory to Emacs load-path.
2. (require 'slynet) and enable (slynet-mode 1).
3. Keep the server on loopback and start it with M-x slynet-start-server, or use M-x slynet-connect-project for the ownership-aware project path.
4. Open the MREPL with M-x slynet-create-mrepl.
5. Use the normal editor commands for region/form/definition/buffer evaluation, file compile/load, source lookup, inspector, diagnostics, and debugger views.
6. When a server disappears, treat buffers marked stale session as historical output, reconnect, and refresh rather than acting through the dead session.

Familiar workflow, Janet semantics

SLY habit	SLYNET equivalent	Important difference
connect to a Lisp	slynet-connect / slynet-connect-project	Connects to a Janet process.
REPL	slynet-create-mrepl	Janet reader/evaluator and Janet values.
eval region/form/defun/buffer	slynet-eval-region, slynet-eval-last-form, slynet-eval-definition, slynet-eval-buffer	Balanced Janet/Lisp syntax is used; there is no CL package reader model.
compile/load file	slynet-compile-current-file, slynet-load-current-file	Diagnostics are Janet-native, not CL compiler notes.
M-. definitions	slynet-find-definitions	Backed by SLYNET’s Janet source index.
inspector	slynet-inspect-value	Back/forward/refresh/actions are SLYNET-native inspector operations.
debugger	slynet-debugger-info	Condition/frame inspection is useful, but not a resumable CL debugger continuation.
interrupt	slynet-interrupt-execution-unit	Cooperative only for SLYNET-managed execution units.
abort pending request	slynet-cancel-latest-request	Cancels client bookkeeping; it does not claim to stop arbitrary backend Janet work.

Semantics that do not migrate literally

Packages and reader state

Janet modules/environments are not Common Lisp packages. SLYNET exposes adapted namespace/package-shaped records where useful, but package-local nicknames and other CL-only behavior are explicitly unsupported or emulated rather than invented.

Conditions and restarts

Janet errors, fibers and debug stacks do not provide the Common Lisp condition and restart protocol. SLYNET can show structured error state, source-linked frames and synthetic/cooperative restart-like actions. It does not claim CL restart equivalence.

Threads and debugger stepping

SLYNET execution units are a managed Janet abstraction. They are not a promise that every Janet runtime fiber behaves like a CL implementation thread. Native step/next/out remains unavailable until a real resumable Janet substrate exists; the UI marks unavailable controls instead of making them clickable.

CLOS/MOP

Janet has no CLOS/MOP substrate. Operations that require it remain unsupported. Use Janet data/functions/prototypes directly rather than attempting to port MOP workflows mechanically.

Suggested Emacs configuration

(add-to-list 'load-path (expand-file-name "~/src/slynet/emacs"))
(require 'slynet)

(setq slynet-server-directory (expand-file-name "~/src/slynet"))
(setq slynet-server-command '("janet" "slynet/cli.janet" "--tcp"))

(slynet-mode 1)

The public command prefix is C-c C-s; the README contains the current command and key table.

Embedding migration

Applications embedding SLYNET should import the API-v1 module instead of CLI, registry or backend internals:

(import slynet/api :as slynet)

(def context (slynet/create-context))
(defer (slynet/close-context context))

(slynet/call-rpc 'ping :pong)
(pp (slynet/context-status context))

The older (import slynet/slynet-api ...) path is an API-v1 compatibility shim. New code should use slynet/api; see the embedding API page for the exact compatibility and deprecation policy.

An executable example ships in release artifacts as examples/embed-server.janet; ./examples/embed-server.janet --check verifies the embedding API without opening a listener.

Security model

Do not carry over assumptions from a locally trusted Lisp development setup to an exposed network service. SLYNET evaluates Janet code with the server process user’s authority. API-v1 server helpers and documented defaults bind to 127.0.0.1; authentication, authorization, encryption and sandboxing are not provided by the SLYNET protocol itself.

Checking whether a SLY feature exists

Use these sources in order:

1. docs/generated/protocol-inventory.yml for generated operation-level truth;
2. docs/generated/protocol-coverage.md for the release-critical stable subset;
3. DEVELOPMENT_STATUS.md for the current development-tree interpretation;
4. ROADMAP.md for planned work.

Historical missing-protocol checklists are not release authority.