SLIME
*****

SLIME is the ``Superior Lisp Interaction Mode for Emacs''. This is the manual for version 1.2.

Introduction
************

SLIME is the ``Superior Lisp Interaction Mode for Emacs.''

SLIME extends Emacs with new support for interactive programming in Common Lisp. The features are centred around slime-mode, an Emacs minor-mode that complements the standard lisp-mode. While lisp-mode supports editing Lisp source files, slime-mode adds support for interacting with a running Common Lisp process for compilation, debugging, documentation lookup, and so on.

The slime-mode programming environment follows the example of Emacs's native Emacs Lisp environment. We have also included good ideas from similar systems (such as ILISP) and some new ideas of our own.

SLIME is constructed from two parts: a user-interface written in Emacs Lisp, and a supporting server program written in Common Lisp. The two sides are connected together with a socket and communicate using an RPC-like protocol.

The Lisp server is primarily written in portable Common Lisp. The required implementation-specific functionality is specified by a well-defined interface and implemented separately for each Lisp implementation. This makes SLIME readily portable.

Getting started
***************

This chapter tells you how to get SLIME up and running.

Supported Platforms
===================

SLIME supports a wide range of operating systems and Lisp implementations. SLIME runs on Unix systems, Mac OSX, and Microsoft Windows. GNU Emacs versions 20 and 21 and XEmacs version 21 are supported.

The supported Lisp implementations, roughly ordered from the best-supported, are:

  * CMU Common Lisp (CMUCL), 18e or newer

  * Steel Bank Common Lisp (SBCL), latest official release

  * OpenMCL, version 0.14.3

  * LispWorks, version 4.3 or newer

  * Allegro Common Lisp (ACL), version 6 or newer

  * CLISP, version 2.33.2 or newer

  * Armed Bear Common Lisp (ABCL)

  * Corman Common Lisp (CCL), version 2.51 or newer with the patches from http://www.grumblesmurf.org/lisp/corman-patches)

  * Scieneer Common Lisp (SCL), version 1.2.7 or newer

Most features work uniformly across implementations, but some are prone to variation. These include the precision of placing compiler-note annotations, XREF support, and fancy debugger commands (like ``restart frame'').

Downloading SLIME
=================

You can choose between using a released version of SLIME or accessing our CVS repository directly. You can download the latest released version from our website:

http://www.common-lisp.net/project/slime/

We recommend that users who participate in the slime-devel mailing list use the CVS version of the code.

Downloading from CVS
--------------------

SLIME is available from the CVS repository on common-lisp.net. You have the option to use either the very latest code or the tagged FAIRLY-STABLE snapshot.

The latest version tends to have more features and fewer bugs than the FAIRLY-STABLE version, but it can be unstable during times of major surgery. As a rule-of-thumb recommendation we suggest that if you follow the slime-devel mailing list then you're better off with the latest version (we'll send a note when it's undergoing major hacking). If you don't follow the mailing list you won't know the status of the latest code, so tracking FAIRLY-STABLE or using a released version is the safe option.

If you checkout from CVS then remember to cvs update occasionally.  Improvements are continually being committed, and the FAIRLY-STABLE tag is moved forward from time to time (about once per month).

CVS incantations
----------------

To download SLIME you first configure your CVSROOT and login to the repository.

     export CVSROOT=:pserver:anonymous@common-lisp.net:/project/slime/cvsroot
     cvs login

(The password is anonymous)

The latest version can then be checked out with:

     cvs checkout slime

Or the FAIRLY-STABLE version can be checked out with:

     cvs checkout -rFAIRLY-STABLE slime

If you want to find out what's new since the version you're currently running, you can diff the local ChangeLog against the repository version:

     cvs diff -rHEAD ChangeLog      # or: -rFAIRLY-STABLE

Installation
============

With a Lisp implementation that can be started from the command-line, installation just requires a few lines in your ~/.emacs:

     (setq inferior-lisp-program "the path to your Lisp system")
     (add-to-list 'load-path "the path of your slime directory")
     (require 'slime)
     (slime-setup)

We recommend not loading the ILISP package into Emacs if you intend to use SLIME. Doing so will add a lot of extra bindings to the keymap for Lisp source files that may be confusing and may not work correctly for a Lisp process started by SLIME.

Running SLIME
=============

SLIME is started with the Emacs command M-x slime. This uses the inferior-lisp package to start a Lisp process, loads and starts the Lisp-side server (known as ``Swank''), and establishes a socket connection between Emacs and Lisp. Finally a REPL buffer is created where you can enter Lisp expressions for evaluation.

At this point SLIME is up and running and you can start exploring.

slime-mode
**********

SLIME's commands are provided via slime-mode, a minor-mode used in conjunction with Emacs's lisp-mode. This chapter describes the slime-mode and its relatives.

User-interface conventions
==========================

To use SLIME comfortably it is important to understand a few ``global'' user-interface characteristics. The most important principles are described in this section.

Temporary buffers
-----------------

Some SLIME commands create temporary buffers to display their results. Although these buffers usually have their own special-purpose major-modes, certain conventions are observed throughout.

Temporary buffers can be dismissed by pressing q. This kills the buffer and restores the window configuration as it was before the buffer was displayed. Temporary buffers can also be killed with the usual commands like kill-buffer, in which case the previous window configuration won't be restored.

Pressing RET is supposed to ``do the most obvious useful thing.'' For instance, in an apropos buffer this prints a full description of the symbol at point, and in an XREF buffer it displays the source code for the reference at point. This convention is inherited from Emacs's own buffers for apropos listings, compilation results, etc.

Temporary buffers containing Lisp symbols use slime-mode in addition to any special mode of their own. This makes the usual SLIME commands available for describing symbols, looking up function definitions, and so on.

Key bindings
------------

In general we try to make our key bindings fit with the overall Emacs style. We also have the following somewhat unusual convention of our own: when entering a three-key sequence, the final key can be pressed either with control or unmodified. For example, the slime-describe-symbol command is bound to C-c C-d d, but it also works to type C-c C-d C-d. We're simply binding both key sequences because some people like to hold control for all three keys and others don't, and with the two-key prefix we're not afraid of running out of keys.

There is one exception to this rule, just to trip you up. We never bind C-h anywhere in a key sequence, so C-c C-d C-h doesn't do the same thing as C-c C-d h. This is because Emacs has a builtin default so that typing a prefix followed by C-h will display all bindings starting with that prefix, so C-c C-d C-h will actually list the bindings for all documentation commands. This feature is just a bit too useful to clobber!

*inferior-lisp* buffer
----------------------

SLIME internally uses the inferior-lisp package to start Lisp processes. This has a few user-visible consequences, some good and some not-so-terribly. To avoid confusion it is useful to understand the interactions.

The buffer *inferior-lisp* contains the Lisp process's own top-level. This direct access to Lisp is useful for troubleshooting, and some degree of SLIME integration is available using the inferior-slime-mode. However, in normal use we recommend using the fully-integrated SLIME REPL and ignoring the *inferior-lisp* buffer.

An unfortunate property of inferior-lisp is it inserts some commands of its own directly into the lisp-mode keymap, such that they aren't easily disabled. This makes Lisp source buffers slightly schizophrenic, having both SLIME and inferior-lisp commands bound to keys and operating independently.

SLIME overrides most key bindings, so in practice you are unlikely to accidentally use an inferior-lisp command. If you do find a command that pops up the *inferior-lisp* buffer, that command doesn't belong to SLIME, and you should probably lookup our equivalent.

Multithreading
--------------

If the Lisp system supports multithreading, SLIME spawns a new thread for each request, e.g., C-x C-e creates a new thread to evaluate the expression.  An exception to this rule are requests from the REPL: all commands entered in the REPL buffer are evaluated in a dedicated REPL thread.

Some complications arise with multithreading and special variables. Non-global special bindings are thread-local, e.g., changing the value of a let bound special variable in one thread has no effect on the binding of the variables with the same name in other threads.  This makes it sometimes difficult to change the printer or reader behaviour for new threads.  The variable swank:*default-worker-thread-bindings* was introduced for such situtuations: instead of modifying the global value of a variable, add a binding the swank:*default-worker-thread-bindings*.  E.g., with the following code, new threads will read floating point values as doubles by default:

     (push '(*read-default-float-format* . double-float)
            swank:*default-worker-thread-bindings*).

Commands
========

Compilation commands
--------------------

SLIME has fancy commands for compiling functions, files, and packages. The fancy part is that notes and warnings offered by the Lisp compiler are intercepted and annotated directly onto the corresponding expressions in the Lisp source buffer. (Give it a try to see what this means.)

C-c C-k
     slime-compile-and-load-file

     Compile and load the current buffer's source file.

C-c M-k
     slime-compile-file

     Compile (but don't load) the current buffer's source file.

C-c C-c
     slime-compile-defun

     Compile the top-level form at point.

The annotations are indicated as underlining on source forms. The compiler message associated with an annotation can be read either by placing the mouse over the text or with the selection commands below.

M-n
M-p
     slime-next-note, slime-previous-note

     These commands move the point between compiler notes and display the new note.

C-c M-c
     slime-remove-notes

     Remove all annotations from the buffer.

Finding definitions (``Meta-Point'').
-------------------------------------

The familiar M-. command is provided. For generic functions this command finds all methods, and with some systems it does other fancy things (like tracing structure accessors to their DEFSTRUCT definition).

M-.
     slime-edit-definition

     Go to the definition of the symbol at point.

M-,
     slime-pop-find-definition-stack Go back from a definition found with M-.. This gives multi-level backtracking when M-. has been used several times.

Lisp Evaluation
---------------

These commands each evaluate a Lisp expression in a different way. By default they show their results in a message, but a prefix argument causes the results to be printed in the REPL instead.

C-M-x
     slime-eval-defun

     Evaluate top-level form.

C-x C-e
     slime-eval-last-expression

     Evaluate the expression before point.

C-c C-p
     slime-pprint-eval-last-expression

     Evaluate the expression before point and pretty-print the result.

C-c C-r
     slime-eval-region

     Evaluate the region.

C-c :
     slime-interactive-eval

     Evaluate an expression read from the minibuffer.

M-x slime-scratch
     Create a *slime-scratch* buffer. In this buffer you can enter Lisp expressions and evaluate them with C-j, like in Emacs's *scratch* buffer.

If `C-M-x' or `C-x C-e' is given a numeric argument, it inserts the value into the current buffer at point, rather than displaying it in the echo area.

Documentation
-------------

SLIME's online documentation commands follow the example of Emacs Lisp. The commands all share the common prefix C-c C-d and allow the final key to be modified or unmodified (see Key bindings.)

C-c C-d d
     slime-describe-symbol

     Describe the symbol at point.

C-c C-d a
     slime-apropos

     Apropos search. Search Lisp symbol names for a substring match and present their documentation strings. By default the external symbols of all packages are searched. With a prefix argument you can choose a specific package and whether to include unexported symbols.

C-c C-d z
     slime-apropos-all

     Like slime-apropos but also includes internal symbols by default.

C-c C-d p
     slime-apropos-package

     Show apropos results of all symbols in a package. This command is for browsing a package at a high-level. With package-name completion it also serves as a rudimentary Smalltalk-ish image-browser.

C-c C-d h
     slime-hyperspec-lookup

     Lookup the symbol at point in the Common Lisp Hyperspec. This uses the familiar hyperspec.el to show the appropriate section in a web browser. The Hyperspec is found either on the Web or in common-lisp-hyperspec-root, and the browser is selected by browse-url-browser-function.

C-c C-d ~
     common-lisp-hyperspec-format

     Lookup a format character in the Common Lisp Hyperspec.

Programming Helpers
-------------------

M-TAB
     slime-complete-symbol

     Complete the symbol at point. Note that three styles of completion are available in SLIME, and the default differs from normal Emacs completion. See Emacs-side customization.

C-c M-i
     slime-fuzzy-complete-symbol

     Presents a list of likely completions to choose from for an abbreviation at point.  This is a third completion method and it is very different from the more traditional completion to which slime-complete-symbol defaults.  It attempts to complete a symbol all at once, instead of in pieces.  For example, ``mvb'' will find ``multiple-value-bind'' and ``norm-df'' will find ``least-positive-normalized-double-float''.  This can also be selected as the method of completion used for slime-complete-symbol.

SPC
     slime-space

     The space key inserts a space and also looks up and displays the argument list for the function at point, if there is one.

C-c C-s
     slime-complete-form

     Looks up and inserts into the current buffer the argument list for the function at point, if there is one.  More generally, the command completes an incomplete form with a template for the missing arguments. There is special code for discovering extra keywords of generic functions and for handling make-instance and defmethod. Examples:

          (subseq "abc" <C-c C-s>
            --inserts--> start [end])
          (find 17 <C-c C-s>
            --inserts--> sequence :from-end from-end :test test
                         :test-not test-not :start start :end end
                         :key key)
          (find 17 '(17 18 19) :test #'= <C-c C-s>
            --inserts--> :from-end from-end
                         :test-not test-not :start start :end end
                         :key key)
          (defclass foo () ((bar :initarg :bar)))
          (defmethod print-object <C-c C-s>
            --inserts-->   (object stream)
                         body...)
          (defmethod initialize-instance :after ((object foo) &key blub))
          (make-instance 'foo <C-c C-s>
            --inserts--> :bar bar :blub blub initargs...)

C-c C-m
     slime-macroexpand-1

     Macroexpand the expression at point once.  If invoked with a prefix argument, use macroexpand instead of macroexpand-1.

C-c M-m
     slime-macroexpand-all

     Fully macroexpand the expression at point.

C-c C-t
     slime-toggle-trace-fdefinition

     Toggle tracing of the function at point.  If invoked with a prefix argument, read additional information, like which particular method should be traced.

C-c M-d
     slime-disassemble-symbol

     Disassemble the function definition of the symbol at point.

Abort/Recovery
--------------

C-c C-b
     slime-interrupt

     Interrupt Lisp (send SIGINT).

C-c ~
     slime-sync-package-and-default-directory

     Synchronize the current package and working directory from Emacs to Lisp.

C-c M-p
     slime-repl-set-package

     Set the current package of the REPL.

Cross-reference
---------------

SLIME's cross-reference commands are based on the support provided by the Lisp system, which varies widely between Lisps. For systems with no builtin XREF support SLIME queries a portable XREF package, which is taken from the CMU AI
Repository and bundled with SLIME.

Each command operates on the symbol at point, or prompts if there is none. With a prefix argument they always prompt. You can either enter the key bindings as shown here or with the control modified on the last key, see Key bindings.

C-c C-w c
     slime-who-calls

     Show function callers.

C-c C-w r
     slime-who-references

     Show references to global variable.

C-c C-w b
     slime-who-binds

     Show bindings of a global variable.

C-c C-w s
     slime-who-sets

     Show assignments to a global variable.

C-c C-w m
     slime-who-macroexpands

     Show expansions of a macro.

M-x slime-who-specializes
     Show all known methods specialized on a class.

There are also ``List callers/callees'' commands. These operate by rummaging through function objects on the heap at a low-level to discover the call graph. They are only available with some Lisp systems, and are most useful as a fallback when precise XREF information is unavailable.

C-c <
     slime-list-callers

     List callers of a function.

C-c >
     slime-list-callees

     List callees of a function.

Inspector
---------

The SLIME inspector is a very fancy Emacs-based alternative to the standard INSPECT function. The inspector presents objects in Emacs buffers using a combination of plain text, hyperlinks to related objects, and ``actions'' that can be selected to invoke Lisp code on the inspected object. For example, to present a generic function the inspector shows the documentation in plain text and presents each method with both a hyperlink to inspect the method object and a ``remove method'' action that you can invoke interactively.

The inspector can easily be specialized for the objects in your own programs. For details see the the inspect-for-emacs generic function in swank-backend.lisp.

C-c I
     slime-inspect

     Inspect the value of an expression entered in the minibuffer.

The standard commands available in the inspector are:

RET
     slime-inspector-operate-on-point

     If point is on a value then recursivly call the inspcetor on that value. If point is on an action then call that action.

d
     slime-inspector-describe

     Describe the slot at point.

l
     slime-inspector-pop

     Go back to the previous object (return from RET).

n
     slime-inspector-next

     The inverse of l. Also bound to SPC.

q
     slime-inspector-quit

     Dismiss the inspector buffer.

     M-RET, slime-inspector-copy-down Evaluate the value under point via the REPL (to set `*').

Profiling
---------

M-x slime-toggle-profile-fdefinition
     Toggle profiling of a function.

M-x slime-profile-package
     Profile all functions in a package.

M-x slime-unprofile-all
     Unprofile all functions.

M-x slime-profile-report
     Report profiler data.

M-x slime-profile-reset
     Reset profiler data.

Semantic indentation
====================

SLIME automatically discovers how to indent the macros in your Lisp system. To do this the Lisp side scans all the macros in the system and reports to Emacs all the ones with &body arguments. Emacs then indents these specially, putting the first arguments four spaces in and the ``body'' arguments just two spaces, as usual.

This should ``just work.'' If you are a lucky sort of person you needn't read the rest of this section.

To simplify the implementation, SLIME doesn't distinguish between macros with the same symbol-name but different packages. This makes it fit nicely with Emacs's indentation code. However, if you do have several macros with the same symbol-name then they will all be indented the same way, arbitrarily using the style from one of their arglists. You can find out which symbols are involved in collisions with:

     (swank:print-indentation-lossage)

If a collision causes you irritation, don't have a nervous breakdown, just override the Elisp symbol's common-lisp-indent-function property to your taste. SLIME won't override your custom settings, it just tries to give you good defaults.

A more subtle issue is that imperfect caching is used for the sake of performance.  (Of course we made sure it was actually too slow before making the ugly optimization.) In an ideal world, Lisp would automatically scan every symbol for indentation changes after each command from Emacs. However, this is too expensive to do every time. Instead Lisp usually just scans the symbols whose home package matches the one used by the Emacs buffer where the request comes from. That is sufficient to pick up the indentation of most interactively-defined macros. To catch the rest we make a full scan of every symbol each time a new Lisp package is created between commands -- that takes care of things like new systems being loaded.

You can use M-x slime-update-indentation to force all symbols to be scanned for indentation information.

Reader conditional fontification
================================

SLIME automatically evaluates reader-conditional expressions in source buffers and ``grays out'' code that will be skipped for the current Lisp connection.

REPL: the ``top level''
***********************

SLIME uses a custom Read-Eval-Print Loop (REPL, also known as a ``top level''). The REPL user-interface is written in Emacs Lisp, which gives more Emacs-integration than the traditional comint-based Lisp interaction:

  * Conditions signalled in REPL expressions are debugged with SLDB.

  * Return values are distinguished from printed output by separate Emacs faces (colours).

  * Emacs manages the REPL prompt with markers. This ensures that Lisp output is inserted in the right place, and doesn't get mixed up with user input.

REPL commands
=============

RET
     slime-repl-return

     Evaluate the current input in Lisp if it is complete. If incomplete, open a new line and indent. If a prefix argument is given then the input is evaluated without checking for completeness.

C-RET
     slime-repl-closing-return

     Close any unmatched parenthesis and then evaluate the current input in Lisp. Also bound to M-RET.

C-j
     slime-repl-newline-and-indent

     Open and indent a new line.

C-c C-c
     slime-interrupt

     Interrupt the Lisp process with SIGINT.

TAB
     slime-complete-symbol

     Complete the symbol at point.

C-c C-o
     slime-repl-clear-output

     Remove the output and result of the previous expression from the buffer.

C-c C-t
     slime-repl-clear-buffer

     Clear the entire buffer, leaving only a prompt.

Input navigation
================

C-a
     slime-repl-bol

     Go to the beginning of the line, but stop at the REPL prompt.

M-n
M-p
M-s
M-r
     slime-repl-{next,previous}-input

     slime-repl-{next,previous}-matching-input

     comint-style input history commands.

C-c C-n
C-c C-p
     slime-repl-next-prompt, slime-repl-previous-prompt

     Move between the current and previous prompts in the REPL buffer.

C-M-a
C-M-e
     slime-repl-beginning-of-defun, slime-repl-end-of-defun These commands are like beginning-of-defun and end-of-defun, but when used inside the REPL input area they instead go directly to the beginning or the end, respectively.

Shortcuts
=========

``Shortcuts'' are a special set of REPL commands that are invoked by name. To invoke a shortcut you first press , (comma) at the REPL prompt and then enter the shortcut's name when prompted.

Shortcuts deal with things like switching between directories and compiling and loading Lisp systems. The exact set of shortcuts is not currently documented in this manual, but you can use the help shortcut to list them interactively.

SLDB: the SLIME debugger
************************

SLIME has a custom Emacs-based debugger called SLDB. Conditions signalled in the Lisp system invoke SLDB in Emacs by way of the Lisp *DEBUGGER-HOOK*.

SLDB pops up a buffer when a condition is signalled. The buffer displays a description of the condition, a list of restarts, and a backtrace. Commands are offered for invoking restarts, examining the backtrace, and poking around in stack frames.

Examining frames
================

Commands for examining the stack frame at point.

t
     sldb-toggle-details

     Toggle display of local variables and CATCH tags.

v
     sldb-show-source

     View the frame's current source expression. The expression is presented in the Lisp source file's buffer.

e
     sldb-eval-in-frame

     Evaluate an expression in the frame. The expression can refer to the available local variables in the frame.

d
     sldb-pprint-eval-in-frame

     Evaluate an expression in the frame and pretty-print the result in a temporary buffer.

D
     sldb-disassemble

     Disassemble the frame's function. Includes information such as the instruction pointer within the frame.

i
     sldb-inspect-in-frame

     Inspect the result of evaluating an expression in the frame.

Invoking restarts
=================

a
     sldb-abort

     Invoke the ABORT restart.

q
     sldb-quit

     ``Quit'' -- THROW to a tag that the top-level SLIME request-loop catches.

c
     sldb-continue

     Invoke the CONTINUE restart.

0 ... 9
     Invoke a restart by number.

Restarts can also be invoked by pressing RET or Mouse-2 on them in the buffer.

Navigating between frames
=========================

n

p
     sldb-down, sldb-up

     Move between frames.

M-n

M-p
     sldb-details-{down,up}

     Move between frames ``with sugar'': hide the details of the original frame and display the details and source code of the next. Sugared motion makes you see the details and source code for the current frame only.

Miscellaneous Commands
======================

r
     sldb-restart-frame

     Restart execution of the frame with the same arguments it was originally called with. (This command is not available in all implementations.)

R
     sldb-return-from-frame

     Return from the frame with a value entered in the minibuffer. (This command is not available in all implementations.)

s
     sldb-step

     Step to the next expression in the frame. (This command is not available in all implementations.)

B
     sldb-break-with-default-debugger

     Exit SLDB and debug the condition using the Lisp system's default debugger.

:
     slime-interactive-eval

     Evaluate an expression entered in the minibuffer.

Extras
******

slime-selector
==============

The slime-selector command is for quickly switching to important buffers: the REPL, SLDB, the Lisp source you were just hacking, etc. Once invoked the command prompts for a single letter to specify which buffer it should display. Here are some of the options:

?
     A help buffer listing all slime-selectors's available buffers.

r
     The REPL buffer for the current SLIME connection.

d
     The most recently activated SLDB buffer for the current connection.

l
     The most recently visited lisp-mode source buffer.

s
     The *slime-scratch* buffer. See slime-scratch.

slime-selector doesn't have a key binding by default but we suggest that you assign it a global one. You can bind C-c s like this:

     (global-set-key "\C-cs" 'slime-selector)

And then you can switch to the REPL from anywhere with C-c s
r.

The macro def-slime-selector-method can be used to define new buffers for slime-selector to find.

slime-autodoc-mode
==================

slime-autodoc-mode is an additional minor-mode for automatically showing information about symbols near the point. For function names the argument list is displayed and for global variables we show the value. This is a clone of eldoc-mode for Emacs Lisp.

The mode can be enabled in the slime-setup call of your ~/.emacs:

     (slime-setup :autodoc t)

Multiple connections
====================

SLIME is able to connect to multiple Lisp processes at the same time. The M-x slime command, when invoked with a prefix argument, will offer to create an additional Lisp process if one is already running. This is often convenient, but it requires some understanding to make sure that your SLIME commands execute in the Lisp that you expect them to.

Some buffers are tied to specific Lisp processes. Each Lisp connection has its own REPL buffer, and all expressions entered or SLIME commands invoked in that buffer are sent to the associated connection. Other buffers created by SLIME are similarly tied to the connections they originate from, including SLDB buffers, apropos result listings, and so on. These buffers are the result of some interaction with a Lisp process, so commands in them always go back to that same process.

Commands executed in other places, such as slime-mode source buffers, always use the ``default'' connection. Usually this is the most recently established connection, but this can be reassigned via the ``connection list'' buffer:

C-c C-x c
     slime-list-connections

     Pop up a buffer listing the established connections.

The buffer displayed by slime-list-connections gives a one-line summary of each connection. The summary shows the connection's serial number, the name of the Lisp implementation, and other details of the Lisp process. The current ``default'' connection is indicated with an asterisk.

The commands available in the connection-list buffer are:

RET
     slime-goto-connection

     Pop to the REPL buffer of the connection at point.

d
     slime-connection-list-make-default

     Make the connection at point the ``default'' connection. It will then be used for commands in slime-mode source buffers.

g
     slime-update-connection-list

     Update the connection list in the buffer.

q
     slime-temp-buffer-quit

     Quit the connection list (kill buffer, restore window configuration).

Typeout frames
==============

A ``typeout frame'' is a special Emacs frame which is used instead of the echo area (minibuffer) to display messages from SLIME commands. This is an optional feature. The advantage of a typeout frame over the echo area is that it can hold more text, it can be scrolled, and its contents don't disappear when you press a key. All potentially long messages are sent to the typeout frame, such as argument lists, macro expansions, and so on.

M-x slime-ensure-typeout-frame
     Ensure that a typeout frame exists, creating one if necessary.

If the typeout frame is closed then the echo area will be used again as usual.

To have a typeout frame created automatically at startup you can use the slime-connected-hook:

     (add-hook 'slime-connected-hook 'slime-ensure-typeout-frame)

Customization
*************

Emacs-side
==========

The Emacs part of SLIME can be configured with the Emacs customize system, just use M-x customize-group slime RET. Because the customize system is self-describing, we only cover a few important or obscure configuration options here in the manual.

slime-truncate-lines
     The value to use for truncate-lines in line-by-line summary buffers popped up by SLIME. This is t by default, which ensures that lines do not wrap in backtraces, apropos listings, and so on. It can however cause information to spill off the screen.

slime-multiprocessing
     This should be set to t if you want to use multiprocessing (threads) in your Lisp system. It causes any necessary initialization to be performed during Lisp server startup.

slime-complete-symbol-function
     The function to use for completion of Lisp symbols. Three completion styles are available. The default slime-complete-symbol* performs completion ``in parallel'' over the hyphen-delimited sub-words of a symbol name. (This style of completion is modelled on completer.el by Chris McConnell. That package is bundled with ILISP.) Formally this means that ``a-b-c'' can complete to any symbol matching the regular expression ``^a.*-b.*-c.*'' (where ``dot'' matches anything but a hyphen). Examples give a more intuitive feeling:

       * m-v-b completes to multiple-value-bind.

       * w-open is ambiguous: it completes to either with-open-file or with-open-stream. The symbol is expanded to the longest common completion (with-open-) and the point is placed at the first point of ambiguity, which in this case is the end.

       * w--stream completes to with-open-stream.

     An alternative is slime-simple-complete-symbol, which completes in the usual Emacs way.  Finally, there is slime-fuzzy-complete-symbol, which is quite different from both of the above and tries to find best matches to an abbreviated symbol. It also has its own keybinding, defaulting to C-c M-i. See slime-fuzzy-complete-symbol, for more information.

slime-translate-to-lisp-filename-function
slime-translate-from-lisp-filename-function
     These functions can be used to translate filenames between Emacs and the Lisp system. They are useful if you run Emacs and Lisp on separate machines which share a common file system but use a different directory structure (different ``mount points''). This is most common with SMB-based file sharing.

slime-net-coding-system
     If you want to transmit Unicode characters between Emacs and the Lisp system, you should customize this variable.  E.g., if you use SBCL, you can set:

          (setq slime-net-coding-system 'utf-8-unix)

     To actually display Unicode characters you also need appropriate fonts, otherwise the characters will be rendered as hollow boxes.  If you are using Allegro CL and GNU Emacs, you can also use emacs-mule-unix as coding system.  GNU Emacs has often nicer fonts for the latter encoding.

Hooks
-----

slime-mode-hook
     This hook is run each time a buffer enters slime-mode. It is most useful for setting buffer-local configuration in your Lisp source buffers. An example use is to enable slime-autodoc-mode (see slime-autodoc-mode.)

slime-connected-hook
     This hook is run when SLIME establishes a connection to a Lisp server. An example use is to create a Typeout frame (see Typeout frames.)

sldb-hook
     This hook is run after SLDB is invoked. The hook functions are called from the SLDB buffer after it is initialized. An example use is to add sldb-print-condition to this hook, which makes all conditions debugged with SLDB be recorded in the REPL buffer.

Lisp-side (Swank)
=================

The Lisp server side of SLIME (known as ``Swank'') offers several variables to configure. The initialization file ~/.swank.lisp is automatically evaluated at startup and can be used to set these variables.

Communication style
-------------------

The most important configurable is SWANK:*COMMUNICATION-STYLE*, which specifies the mechanism by which Lisp reads and processes protocol messages from Emacs. The choice of communication style has a global influence on SLIME's operation.

The available communication styles are:

:FD-HANDLER
     This style uses the classical Unix-style ``select()-loop.'' Swank registers the communication socket with an event-dispatching framework (such as SERVE-EVENT in CMUCL and SBCL) and receives a callback when data is available. In this style requests from Emacs are only detected and processed when Lisp enters the event-loop. This style is simple and predictable.

:SIGIO
     This style uses signal-driven I/O with a SIGIO signal handler. Lisp receives requests from Emacs along with a signal, causing it to interrupt whatever it is doing to serve the request. This style has the advantage of responsiveness, since Emacs can perform operations in Lisp even while it is busy doing other things. It also allows Emacs to issue requests concurrently, e.g. to send one long-running request (like compilation) and then interrupt that with several short requests before it completes. The disadvantages are that it may conflict with other uses of SIGIO by Lisp code, and it may cause untold havoc by interrupting Lisp at an awkward moment.

:SPAWN
     This style uses multiprocessing support in the Lisp system to execute each request in a separate thread. This style has similar properties to :SIGIO, but it does not use signals and all requests issued by Emacs can be executed in parallel.

The default request handling style is chosen according to the capabilities your Lisp system. The general order of preference is :SPAWN, then :SIGIO, then :FD-HANDLER. You can check the default style by calling SWANK-BACKEND:PREFERRED-COMMUNICATION-STYLE. You can also override the default by setting SWANK:*COMMUNICATION-STYLE* in your Swank init file.

Other configurables
-------------------

These Lisp variables can be configured via your ~/.swank.lisp file:

SWANK:*CONFIGURE-EMACS-INDENTATION*
     This variable controls whether indentation styles for &body-arguments in macros are discovered and sent to Emacs. It is enabled by default.

SWANK:*GLOBALLY-REDIRECT-IO*
     When true this causes the standard streams (*standard-output*, etc) to be globally redirected to the REPL in Emacs. When NIL (the default) these streams are only temporarily redirected to Emacs using dynamic bindings while handling requests. Note that *standard-input* is currently never globally redirected into Emacs, because it can interact badly with the Lisp's native REPL by having it try to read from the Emacs one.

SWANK:*GLOBAL-DEBUGGER*
     When true (the default) this causes *DEBUGGER-HOOK* to be globally set to SWANK:SWANK-DEBUGGER-HOOK and thus for SLIME to handle all debugging in the Lisp image. This is for debugging multithreaded and callback-driven applications.

SWANK:*SLDB-PRINTER-BINDINGS*
SWANK:*MACROEXPAND-PRINTER-BINDINGS*
SWANK:*SWANK-PPRINT-BINDINGS*
     These variables can be used to customize the printer in various situations.  The values of the variables are association lists of printer variable names with the corresponding value.  E.g., to enable the pretty printer for formatting backtraces in SLDB, you can use:

          (push '(*print-pretty* . t) swank:*sldb-printer-bindings*).

SWANK:*USE-DEDICATED-OUTPUT-STREAM*
     This variable controls an optimization for sending printed output from Lisp to Emacs. When t (the default) a separate socket is established solely for Lisp to send printed output to Emacs through. Without the optimization it is necessary to send output in protocol-messages to Emacs which must then be decoded, and this doesn't always keep up if Lisp starts ``spewing'' copious output.

SWANK:*DEDICATED-OUTPUT-STREAM-PORT*
     When *USE-DEDICATED-OUTPUT-STREAM* is t the stream will be opened on this port. The default value, 0, means that the stream will be opened on some random port.

SWANK:*LOG-EVENTS*
     Setting this variable to t causes all protocol messages exchanged with Emacs to be printed to *TERMINAL-IO*. This is useful for low-level debugging and for observing how SLIME works ``on the wire.'' The output of *TERMINAL-IO* can be found in your Lisp system's own listener, usually in the buffer *inferior-lisp*.

Credits
*******

The soppy ending...

Hackers of the good hack
========================

SLIME is an Extension of SLIM by Eric Marsden. At the time of writing, the authors and code-contributors of SLIME are:

     [file contributors.texi not included]

... not counting the bundled code from hyperspec.el, CLOCC, and the CMU AI Repository.

Many people on the slime-devel mailing list have made non-code contributions to SLIME. Life is hard though: you gotta send code to get your name in the manual. :-)

Thanks!
=======

We're indebted to the good people of common-lisp.net for their hosting and help, and for rescuing us from ``Sourceforge hell.''

Implementors of the Lisps that we support have been a great help. We'd like to thank the CMUCL maintainers for their helpful answers, Craig Norvell and Kevin Layer at Franz providing Allegro CL licenses for SLIME development, and Peter Graves for his help to get SLIME running with ABCL.

Most of all we're happy to be working with the Lisp implementors who've joined in the SLIME development: Dan Barlow and Christophe Rhodes of SBCL, Gary Byers of OpenMCL, and Martin Simmons of LispWorks. Thanks also to Alain Picard and Memetrics for funding Martin's initial work on the LispWorks backend!