GNU Emacs Lisp Reference Manual

Emacs Lisp

This Info file contains edition 3.0 of the GNU Emacs Lisp Reference Manual, corresponding to GNU Emacs version 23.1.

This is edition 3.0 of the GNU Emacs Lisp Reference Manual,
corresponding to Emacs version 23.1.

Copyright © 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009 Free Software Foundation, Inc.

Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.3 or any later version published by the Free Software Foundation; with the Invariant Sections being “GNU General Public License,” with the Front-Cover texts being “A GNU Manual,” and with the Back-Cover Texts as in (a) below. A copy of the license is included in the section entitled “GNU Free Documentation License.”

(a) The FSF's Back-Cover Text is: “You have the freedom to copy and modify this GNU manual. Buying copies from the FSF supports it in developing GNU and promoting software freedom.”

• Introduction: Introduction and conventions used.
• Lisp Data Types: Data types of objects in Emacs Lisp.
• Numbers: Numbers and arithmetic functions.
• Strings and Characters: Strings, and functions that work on them.
• Lists: Lists, cons cells, and related functions.
• Sequences Arrays Vectors: Lists, strings and vectors are called sequences. Certain functions act on any kind of sequence. The description of vectors is here as well.
• Hash Tables: Very fast lookup-tables.
• Symbols: Symbols represent names, uniquely.
• Evaluation: How Lisp expressions are evaluated.
• Control Structures: Conditionals, loops, nonlocal exits.
• Variables: Using symbols in programs to stand for values.
• Functions: A function is a Lisp program that can be invoked from other functions.
• Macros: Macros are a way to extend the Lisp language.
• Customization: Writing customization declarations.
• Loading: Reading files of Lisp code into Lisp.
• Byte Compilation: Compilation makes programs run faster.
• Advising Functions: Adding to the definition of a function.
• Debugging: Tools and tips for debugging Lisp programs.
• Read and Print: Converting Lisp objects to text and back.
• Minibuffers: Using the minibuffer to read input.
• Command Loop: How the editor command loop works, and how you can call its subroutines.
• Keymaps: Defining the bindings from keys to commands.
• Modes: Defining major and minor modes.
• Documentation: Writing and using documentation strings.
• Files: Accessing files.
• Backups and Auto-Saving: Controlling how backups and auto-save files are made.
• Buffers: Creating and using buffer objects.
• Windows: Manipulating windows and displaying buffers.
• Frames: Making multiple system-level windows.
• Positions: Buffer positions and motion functions.
• Markers: Markers represent positions and update automatically when the text is changed.
• Text: Examining and changing text in buffers.
• Non-ASCII Characters: Non-ASCII text in buffers and strings.
• Searching and Matching: Searching buffers for strings or regexps.
• Syntax Tables: The syntax table controls word and list parsing.
• Abbrevs: How Abbrev mode works, and its data structures.
• Processes: Running and communicating with subprocesses.
• Display: Features for controlling the screen display.
• System Interface: Getting the user id, system type, environment variables, and other such things.

Appendices

• Antinews: Info for users downgrading to Emacs 22.
• GNU Free Documentation License: The license for this documentation.
• GPL: Conditions for copying and changing GNU Emacs.
• Tips: Advice and coding conventions for Emacs Lisp.
• GNU Emacs Internals: Building and dumping Emacs; internal data structures.
• Standard Errors: List of all error symbols.
• Standard Buffer-Local Variables List of variables buffer-local in all buffers.
• Standard Keymaps: List of standard keymaps.
• Standard Hooks: List of standard hook variables.
• Index: Index including concepts, functions, variables, and other terms.

--- The Detailed Node Listing --- ---------------------------------

Here are other nodes that are inferiors of those already listed, mentioned here so you can get to them in one step:

Introduction

• Caveats: Flaws and a request for help.
• Lisp History: Emacs Lisp is descended from Maclisp.
• Conventions: How the manual is formatted.
• Version Info: Which Emacs version is running?
• Acknowledgements: The authors, editors, and sponsors of this manual.

Conventions

• Some Terms: Explanation of terms we use in this manual.
• nil and t: How the symbols nil and t are used.
• Evaluation Notation: The format we use for examples of evaluation.
• Printing Notation: The format we use when examples print text.
• Error Messages: The format we use for examples of errors.
• Buffer Text Notation: The format we use for buffer contents in examples.
• Format of Descriptions: Notation for describing functions, variables, etc.

Format of Descriptions

• A Sample Function Description: A description of an imaginary function, foo.
• A Sample Variable Description: A description of an imaginary variable, electric-future-map.

Lisp Data Types

• Printed Representation: How Lisp objects are represented as text.
• Comments: Comments and their formatting conventions.
• Programming Types: Types found in all Lisp systems.
• Editing Types: Types specific to Emacs.
• Circular Objects: Read syntax for circular structure.
• Type Predicates: Tests related to types.
• Equality Predicates: Tests of equality between any two objects.

Programming Types

• Integer Type: Numbers without fractional parts.
• Floating Point Type: Numbers with fractional parts and with a large range.
• Character Type: The representation of letters, numbers and control characters.
• Symbol Type: A multi-use object that refers to a function, variable, or property list, and has a unique identity.
• Sequence Type: Both lists and arrays are classified as sequences.
• Cons Cell Type: Cons cells, and lists (which are made from cons cells).
• Array Type: Arrays include strings and vectors.
• String Type: An (efficient) array of characters.
• Vector Type: One-dimensional arrays.
• Char-Table Type: One-dimensional sparse arrays indexed by characters.
• Bool-Vector Type: One-dimensional arrays of t or nil.
• Hash Table Type: Super-fast lookup tables.
• Function Type: A piece of executable code you can call from elsewhere.
• Macro Type: A method of expanding an expression into another expression, more fundamental but less pretty.
• Primitive Function Type: A function written in C, callable from Lisp.
• Byte-Code Type: A function written in Lisp, then compiled.
• Autoload Type: A type used for automatically loading seldom-used functions.

Character Type

• Basic Char Syntax: Syntax for regular characters.
• General Escape Syntax: How to specify characters by their codes.
• Ctl-Char Syntax: Syntax for control characters.
• Meta-Char Syntax: Syntax for meta-characters.
• Other Char Bits: Syntax for hyper-, super-, and alt-characters.

Cons Cell and List Types

• Box Diagrams: Drawing pictures of lists.
• Dotted Pair Notation: A general syntax for cons cells.
• Association List Type: A specially constructed list.

String Type

• Syntax for Strings: How to specify Lisp strings.
• Non-ASCII in Strings: International characters in strings.
• Nonprinting Characters: Literal unprintable characters in strings.
• Text Props and Strings: Strings with text properties.

Editing Types

• Buffer Type: The basic object of editing.
• Marker Type: A position in a buffer.
• Window Type: Buffers are displayed in windows.
• Frame Type: Windows subdivide frames.
• Terminal Type: A terminal device displays frames.
• Window Configuration Type: Recording the way a frame is subdivided.
• Frame Configuration Type: Recording the status of all frames.
• Process Type: A subprocess of Emacs running on the underlying OS.
• Stream Type: Receive or send characters.
• Keymap Type: What function a keystroke invokes.
• Overlay Type: How an overlay is represented.
• Font Type: Fonts for displaying text.

Numbers

• Integer Basics: Representation and range of integers.
• Float Basics: Representation and range of floating point.
• Predicates on Numbers: Testing for numbers.
• Comparison of Numbers: Equality and inequality predicates.
• Numeric Conversions: Converting float to integer and vice versa.
• Arithmetic Operations: How to add, subtract, multiply and divide.
• Rounding Operations: Explicitly rounding floating point numbers.
• Bitwise Operations: Logical and, or, not, shifting.
• Math Functions: Trig, exponential and logarithmic functions.
• Random Numbers: Obtaining random integers, predictable or not.

Strings and Characters

• String Basics: Basic properties of strings and characters.
• Predicates for Strings: Testing whether an object is a string or char.
• Creating Strings: Functions to allocate new strings.
• Modifying Strings: Altering the contents of an existing string.
• Text Comparison: Comparing characters or strings.
• String Conversion: Converting to and from characters and strings.
• Formatting Strings: format: Emacs's analogue of printf.
• Case Conversion: Case conversion functions.
• Case Tables: Customizing case conversion.

Lists

• Cons Cells: How lists are made out of cons cells.
• List-related Predicates: Is this object a list? Comparing two lists.
• List Elements: Extracting the pieces of a list.
• Building Lists: Creating list structure.
• List Variables: Modifying lists stored in variables.
• Modifying Lists: Storing new pieces into an existing list.
• Sets And Lists: A list can represent a finite mathematical set.
• Association Lists: A list can represent a finite relation or mapping.
• Rings: Managing a fixed-size ring of objects.

Modifying Existing List Structure

• Setcar: Replacing an element in a list.
• Setcdr: Replacing part of the list backbone. This can be used to remove or add elements.
• Rearrangement: Reordering the elements in a list; combining lists.

Sequences, Arrays, and Vectors

• Sequence Functions: Functions that accept any kind of sequence.
• Arrays: Characteristics of arrays in Emacs Lisp.
• Array Functions: Functions specifically for arrays.
• Vectors: Special characteristics of Emacs Lisp vectors.
• Vector Functions: Functions specifically for vectors.
• Char-Tables: How to work with char-tables.
• Bool-Vectors: How to work with bool-vectors.

Hash Tables

• Creating Hash: Functions to create hash tables.
• Hash Access: Reading and writing the hash table contents.
• Defining Hash: Defining new comparison methods.
• Other Hash: Miscellaneous.

Symbols

• Symbol Components: Symbols have names, values, function definitions and property lists.
• Definitions: A definition says how a symbol will be used.
• Creating Symbols: How symbols are kept unique.
• Property Lists: Each symbol has a property list for recording miscellaneous information.

Property Lists

• Plists and Alists: Comparison of the advantages of property lists and association lists.
• Symbol Plists: Functions to access symbols' property lists.
• Other Plists: Accessing property lists stored elsewhere.

Evaluation

• Intro Eval: Evaluation in the scheme of things.
• Forms: How various sorts of objects are evaluated.
• Quoting: Avoiding evaluation (to put constants in the program).
• Eval: How to invoke the Lisp interpreter explicitly.

Kinds of Forms

• Self-Evaluating Forms: Forms that evaluate to themselves.
• Symbol Forms: Symbols evaluate as variables.
• Classifying Lists: How to distinguish various sorts of list forms.
• Function Indirection: When a symbol appears as the car of a list, we find the real function via the symbol.
• Function Forms: Forms that call functions.
• Macro Forms: Forms that call macros.
• Special Forms: "Special forms" are idiosyncratic primitives, most of them extremely important.
• Autoloading: Functions set up to load files containing their real definitions.

Control Structures

• Sequencing: Evaluation in textual order.
• Conditionals: if, cond, when, unless.
• Combining Conditions: and, or, not.
• Iteration: while loops.
• Nonlocal Exits: Jumping out of a sequence.

Nonlocal Exits

• Catch and Throw: Nonlocal exits for the program's own purposes.
• Examples of Catch: Showing how such nonlocal exits can be written.
• Errors: How errors are signaled and handled.
• Cleanups: Arranging to run a cleanup form if an error happens.

Errors

• Signaling Errors: How to report an error.
• Processing of Errors: What Emacs does when you report an error.
• Handling Errors: How you can trap errors and continue execution.
• Error Symbols: How errors are classified for trapping them.

Variables

• Global Variables: Variable values that exist permanently, everywhere.
• Constant Variables: Certain "variables" have values that never change.
• Local Variables: Variable values that exist only temporarily.
• Void Variables: Symbols that lack values.
• Defining Variables: A definition says a symbol is used as a variable.
• Tips for Defining: Things you should think about when you define a variable.
• Accessing Variables: Examining values of variables whose names are known only at run time.
• Setting Variables: Storing new values in variables.
• Variable Scoping: How Lisp chooses among local and global values.
• Buffer-Local Variables: Variable values in effect only in one buffer.
• File Local Variables: Handling local variable lists in files.
• Directory Local Variables: Local variables common to all files in a directory.
• Frame-Local Variables: Frame-local bindings for variables.
• Variable Aliases: Variables that are aliases for other variables.
• Variables with Restricted Values: Non-constant variables whose value can not be an arbitrary Lisp object.

Scoping Rules for Variable Bindings

• Scope: Scope means where in the program a value is visible. Comparison with other languages.
• Extent: Extent means how long in time a value exists.
• Impl of Scope: Two ways to implement dynamic scoping.
• Using Scoping: How to use dynamic scoping carefully and avoid problems.

Buffer-Local Variables

• Intro to Buffer-Local: Introduction and concepts.
• Creating Buffer-Local: Creating and destroying buffer-local bindings.
• Default Value: The default value is seen in buffers that don't have their own buffer-local values.

Functions

• What Is a Function: Lisp functions vs. primitives; terminology.
• Lambda Expressions: How functions are expressed as Lisp objects.
• Function Names: A symbol can serve as the name of a function.
• Defining Functions: Lisp expressions for defining functions.
• Calling Functions: How to use an existing function.
• Mapping Functions: Applying a function to each element of a list, etc.
• Anonymous Functions: Lambda expressions are functions with no names.
• Function Cells: Accessing or setting the function definition of a symbol.
• Obsolete Functions: Declaring functions obsolete.
• Inline Functions: Defining functions that the compiler will open code.
• Declaring Functions: Telling the compiler that a function is defined.
• Function Safety: Determining whether a function is safe to call.
• Related Topics: Cross-references to specific Lisp primitives that have a special bearing on how functions work.

Lambda Expressions

• Lambda Components: The parts of a lambda expression.
• Simple Lambda: A simple example.
• Argument List: Details and special features of argument lists.
• Function Documentation: How to put documentation in a function.

Macros

• Simple Macro: A basic example.
• Expansion: How, when and why macros are expanded.
• Compiling Macros: How macros are expanded by the compiler.
• Defining Macros: How to write a macro definition.
• Backquote: Easier construction of list structure.
• Problems with Macros: Don't evaluate the macro arguments too many times. Don't hide the user's variables.
• Indenting Macros: Specifying how to indent macro calls.

Common Problems Using Macros

• Wrong Time: Do the work in the expansion, not in the macro.
• Argument Evaluation: The expansion should evaluate each macro arg once.
• Surprising Local Vars: Local variable bindings in the expansion require special care.
• Eval During Expansion: Don't evaluate them; put them in the expansion.
• Repeated Expansion: Avoid depending on how many times expansion is done.

Writing Customization Definitions

• Common Keywords: Common keyword arguments for all kinds of customization declarations.
• Group Definitions: Writing customization group definitions.
• Variable Definitions: Declaring user options.
• Customization Types: Specifying the type of a user option.

Customization Types

• Simple Types: Simple customization types: sexp, integer, number, string, file, directory, alist.
• Composite Types: Build new types from other types or data.
• Splicing into Lists: Splice elements into list with :inline.
• Type Keywords: Keyword-argument pairs in a customization type.
• Defining New Types: Give your type a name.

Loading

• How Programs Do Loading: The load function and others.
• Load Suffixes: Details about the suffixes that load tries.
• Library Search: Finding a library to load.
• Loading Non-ASCII: Non-ASCII characters in Emacs Lisp files.
• Autoload: Setting up a function to autoload.
• Repeated Loading: Precautions about loading a file twice.
• Named Features: Loading a library if it isn't already loaded.
• Where Defined: Finding which file defined a certain symbol.
• Unloading: How to "unload" a library that was loaded.
• Hooks for Loading: Providing code to be run when particular libraries are loaded.

Byte Compilation

• Speed of Byte-Code: An example of speedup from byte compilation.
• Compilation Functions: Byte compilation functions.
• Docs and Compilation: Dynamic loading of documentation strings.
• Dynamic Loading: Dynamic loading of individual functions.
• Eval During Compile: Code to be evaluated when you compile.
• Compiler Errors: Handling compiler error messages.
• Byte-Code Objects: The data type used for byte-compiled functions.
• Disassembly: Disassembling byte-code; how to read byte-code.

Advising Emacs Lisp Functions

• Simple Advice: A simple example to explain the basics of advice.
• Defining Advice: Detailed description of defadvice.
• Around-Advice: Wrapping advice around a function's definition.
• Computed Advice: ...is to defadvice as fset is to defun.
• Activation of Advice: Advice doesn't do anything until you activate it.
• Enabling Advice: You can enable or disable each piece of advice.
• Preactivation: Preactivation is a way of speeding up the loading of compiled advice.
• Argument Access in Advice: How advice can access the function's arguments.
• Advising Primitives: Accessing arguments when advising a primitive.
• Combined Definition: How advice is implemented.

Debugging Lisp Programs

• Debugger: How the Emacs Lisp debugger is implemented.
• Edebug: A source-level Emacs Lisp debugger.
• Syntax Errors: How to find syntax errors.
• Test Coverage: Ensuring you have tested all branches in your code.
• Compilation Errors: How to find errors that show up in byte compilation.

The Lisp Debugger

• Error Debugging: Entering the debugger when an error happens.
• Infinite Loops: Stopping and debugging a program that doesn't exit.
• Function Debugging: Entering it when a certain function is called.
• Explicit Debug: Entering it at a certain point in the program.
• Using Debugger: What the debugger does; what you see while in it.
• Debugger Commands: Commands used while in the debugger.
• Invoking the Debugger: How to call the function debug.
• Internals of Debugger: Subroutines of the debugger, and global variables.

Edebug

• Using Edebug: Introduction to use of Edebug.
• Instrumenting: You must instrument your code in order to debug it with Edebug.
• Edebug Execution Modes: Execution modes, stopping more or less often.
• Jumping: Commands to jump to a specified place.
• Edebug Misc: Miscellaneous commands.
• Breaks: Setting breakpoints to make the program stop.
• Trapping Errors: Trapping errors with Edebug.
• Edebug Views: Views inside and outside of Edebug.
• Edebug Eval: Evaluating expressions within Edebug.
• Eval List: Expressions whose values are displayed each time you enter Edebug.
• Printing in Edebug: Customization of printing.
• Trace Buffer: How to produce trace output in a buffer.
• Coverage Testing: How to test evaluation coverage.
• The Outside Context: Data that Edebug saves and restores.
• Edebug and Macros: Specifying how to handle macro calls.
• Edebug Options: Option variables for customizing Edebug.

Breaks

• Breakpoints: Breakpoints at stop points.
• Global Break Condition: Breaking on an event.
• Source Breakpoints: Embedding breakpoints in source code.

The Outside Context

• Checking Whether to Stop: When Edebug decides what to do.
• Edebug Display Update: When Edebug updates the display.
• Edebug Recursive Edit: When Edebug stops execution.

Edebug and Macros

• Instrumenting Macro Calls: The basic problem.
• Specification List: How to specify complex patterns of evaluation.
• Backtracking: What Edebug does when matching fails.
• Specification Examples: To help understand specifications.

Debugging Invalid Lisp Syntax

• Excess Open: How to find a spurious open paren or missing close.
• Excess Close: How to find a spurious close paren or missing open.

Reading and Printing Lisp Objects

• Streams Intro: Overview of streams, reading and printing.
• Input Streams: Various data types that can be used as input streams.
• Input Functions: Functions to read Lisp objects from text.
• Output Streams: Various data types that can be used as output streams.
• Output Functions: Functions to print Lisp objects as text.
• Output Variables: Variables that control what the printing functions do.

Minibuffers

• Intro to Minibuffers: Basic information about minibuffers.
• Text from Minibuffer: How to read a straight text string.
• Object from Minibuffer: How to read a Lisp object or expression.
• Minibuffer History: Recording previous minibuffer inputs so the user can reuse them.
• Initial Input: Specifying initial contents for the minibuffer.
• Completion: How to invoke and customize completion.
• Yes-or-No Queries: Asking a question with a simple answer.
• Multiple Queries: Asking a series of similar questions.
• Reading a Password: Reading a password from the terminal.
• Minibuffer Commands: Commands used as key bindings in minibuffers.
• Minibuffer Contents: How such commands access the minibuffer text.
• Minibuffer Windows: Operating on the special minibuffer windows.
• Recursive Mini: Whether recursive entry to minibuffer is allowed.
• Minibuffer Misc: Various customization hooks and variables.

Completion

• Basic Completion: Low-level functions for completing strings. (These are too low level to use the minibuffer.)
• Minibuffer Completion: Invoking the minibuffer with completion.
• Completion Commands: Minibuffer commands that do completion.
• High-Level Completion: Convenient special cases of completion (reading buffer name, file name, etc.).
• Reading File Names: Using completion to read file names and shell commands.
• Completion Styles: Specifying rules for performing completion.
• Programmed Completion: Writing your own completion-function.

Command Loop

• Command Overview: How the command loop reads commands.
• Defining Commands: Specifying how a function should read arguments.
• Interactive Call: Calling a command, so that it will read arguments.
• Distinguish Interactive: Making a command distinguish interactive calls.
• Command Loop Info: Variables set by the command loop for you to examine.
• Adjusting Point: Adjustment of point after a command.
• Input Events: What input looks like when you read it.
• Reading Input: How to read input events from the keyboard or mouse.
• Special Events: Events processed immediately and individually.
• Waiting: Waiting for user input or elapsed time.
• Quitting: How C-g works. How to catch or defer quitting.
• Prefix Command Arguments: How the commands to set prefix args work.
• Recursive Editing: Entering a recursive edit, and why you usually shouldn't.
• Disabling Commands: How the command loop handles disabled commands.
• Command History: How the command history is set up, and how accessed.
• Keyboard Macros: How keyboard macros are implemented.

Defining Commands

• Using Interactive: General rules for interactive.
• Interactive Codes: The standard letter-codes for reading arguments in various ways.
• Interactive Examples: Examples of how to read interactive arguments.

Input Events

• Keyboard Events: Ordinary characters--keys with symbols on them.
• Function Keys: Function keys--keys with names, not symbols.
• Mouse Events: Overview of mouse events.
• Click Events: Pushing and releasing a mouse button.
• Drag Events: Moving the mouse before releasing the button.
• Button-Down Events: A button was pushed and not yet released.
• Repeat Events: Double and triple click (or drag, or down).
• Motion Events: Just moving the mouse, not pushing a button.
• Focus Events: Moving the mouse between frames.
• Misc Events: Other events the system can generate.
• Event Examples: Examples of the lists for mouse events.
• Classifying Events: Finding the modifier keys in an event symbol. Event types.
• Accessing Mouse: Functions to extract info from mouse events.
• Accessing Scroll: Functions to get info from scroll bar events.
• Strings of Events: Special considerations for putting keyboard character events in a string.

Reading Input

• Key Sequence Input: How to read one key sequence.
• Reading One Event: How to read just one event.
• Event Mod: How Emacs modifies events as they are read.
• Invoking the Input Method: How reading an event uses the input method.
• Quoted Character Input: Asking the user to specify a character.
• Event Input Misc: How to reread or throw away input events.

Keymaps

• Key Sequences: Key sequences as Lisp objects.
• Keymap Basics: Basic concepts of keymaps.
• Format of Keymaps: What a keymap looks like as a Lisp object.
• Creating Keymaps: Functions to create and copy keymaps.
• Inheritance and Keymaps: How one keymap can inherit the bindings of another keymap.
• Prefix Keys: Defining a key with a keymap as its definition.
• Active Keymaps: How Emacs searches the active keymaps for a key binding.
• Searching Keymaps: A pseudo-Lisp summary of searching active maps.
• Controlling Active Maps: Each buffer has a local keymap to override the standard (global) bindings. A minor mode can also override them.
• Key Lookup: Finding a key's binding in one keymap.
• Functions for Key Lookup: How to request key lookup.
• Changing Key Bindings: Redefining a key in a keymap.
• Remapping Commands: A keymap can translate one command to another.
• Translation Keymaps: Keymaps for translating sequences of events.
• Key Binding Commands: Interactive interfaces for redefining keys.
• Scanning Keymaps: Looking through all keymaps, for printing help.
• Menu Keymaps: Defining a menu as a keymap.

Menu Keymaps

• Defining Menus: How to make a keymap that defines a menu.
• Mouse Menus: How users actuate the menu with the mouse.
• Keyboard Menus: How users actuate the menu with the keyboard.
• Menu Example: Making a simple menu.
• Menu Bar: How to customize the menu bar.
• Tool Bar: A tool bar is a row of images.
• Modifying Menus: How to add new items to a menu.

Defining Menus

• Simple Menu Items: A simple kind of menu key binding, limited in capabilities.
• Extended Menu Items: More powerful menu item definitions let you specify keywords to enable various features.
• Menu Separators: Drawing a horizontal line through a menu.
• Alias Menu Items: Using command aliases in menu items.

Major and Minor Modes

• Hooks: How to use hooks; how to write code that provides hooks.
• Major Modes: Defining major modes.
• Minor Modes: Defining minor modes.
• Mode Line Format: Customizing the text that appears in the mode line.
• Imenu: How a mode can provide a menu of definitions in the buffer.
• Font Lock Mode: How modes can highlight text according to syntax.
• Desktop Save Mode: How modes can have buffer state saved between Emacs sessions.

Hooks

• Running Hooks: How to run a hook.
• Setting Hooks: How to put functions on a hook, or remove them.

Major Modes

• Major Mode Basics
• Major Mode Conventions: Coding conventions for keymaps, etc.
• Auto Major Mode: How Emacs chooses the major mode automatically.
• Mode Help: Finding out how to use a mode.
• Derived Modes: Defining a new major mode based on another major mode.
• Generic Modes: Defining a simple major mode that supports comment syntax and Font Lock mode.
• Mode Hooks: Hooks run at the end of major mode functions.
• Example Major Modes: Text mode and Lisp modes.

Minor Modes

• Minor Mode Conventions: Tips for writing a minor mode.
• Keymaps and Minor Modes: How a minor mode can have its own keymap.
• Defining Minor Modes: A convenient facility for defining minor modes.

Mode Line Format

• Mode Line Basics: Basic ideas of mode line control.
• Mode Line Data: The data structure that controls the mode line.
• Mode Line Top: The top level variable, mode-line-format.
• Mode Line Variables: Variables used in that data structure.
• %-Constructs: Putting information into a mode line.
• Properties in Mode: Using text properties in the mode line.
• Header Lines: Like a mode line, but at the top.
• Emulating Mode Line: Formatting text as the mode line would.

Font Lock Mode

• Font Lock Basics: Overview of customizing Font Lock.
• Search-based Fontification: Fontification based on regexps.
• Customizing Keywords: Customizing search-based fontification.
• Other Font Lock Variables: Additional customization facilities.
• Levels of Font Lock: Each mode can define alternative levels so that the user can select more or less.
• Precalculated Fontification: How Lisp programs that produce the buffer contents can also specify how to fontify it.
• Faces for Font Lock: Special faces specifically for Font Lock.
• Syntactic Font Lock: Fontification based on syntax tables.
• Setting Syntax Properties: Defining character syntax based on context using the Font Lock mechanism.
• Multiline Font Lock: How to coerce Font Lock into properly highlighting multiline constructs.

Multiline Font Lock Constructs

• Font Lock Multiline: Marking multiline chunks with a text property.
• Region to Fontify: Controlling which region gets refontified after a buffer change.

Documentation

• Documentation Basics: Good style for doc strings. Where to put them. How Emacs stores them.
• Accessing Documentation: How Lisp programs can access doc strings.
• Keys in Documentation: Substituting current key bindings.
• Describing Characters: Making printable descriptions of non-printing characters and key sequences.
• Help Functions: Subroutines used by Emacs help facilities.

Files

• Visiting Files: Reading files into Emacs buffers for editing.
• Saving Buffers: Writing changed buffers back into files.
• Reading from Files: Reading files into buffers without visiting.
• Writing to Files: Writing new files from parts of buffers.
• File Locks: Locking and unlocking files, to prevent simultaneous editing by two people.
• Information about Files: Testing existence, accessibility, size of files.
• Changing Files: Renaming files, changing protection, etc.
• File Names: Decomposing and expanding file names.
• Contents of Directories: Getting a list of the files in a directory.
• Create/Delete Dirs: Creating and Deleting Directories.
• Magic File Names: Defining "magic" special handling for certain file names.
• Format Conversion: Conversion to and from various file formats.

Visiting Files

• Visiting Functions: The usual interface functions for visiting.
• Subroutines of Visiting: Lower-level subroutines that they use.

Information about Files

• Testing Accessibility: Is a given file readable? Writable?
• Kinds of Files: Is it a directory? A symbolic link?
• Truenames: Eliminating symbolic links from a file name.
• File Attributes: How large is it? Any other names? Etc.
• Locating Files: How to find a file in standard places.

File Names

• File Name Components: The directory part of a file name, and the rest.
• Relative File Names: Some file names are relative to a current directory.
• Directory Names: A directory's name as a directory is different from its name as a file.
• File Name Expansion: Converting relative file names to absolute ones.
• Unique File Names: Generating names for temporary files.
• File Name Completion: Finding the completions for a given file name.
• Standard File Names: If your package uses a fixed file name, how to handle various operating systems simply.

File Format Conversion

• Format Conversion Overview: insert-file-contents and write-region.
• Format Conversion Round-Trip: Using format-alist.
• Format Conversion Piecemeal: Specifying non-paired conversion.

Backups and Auto-Saving

• Backup Files: How backup files are made; how their names are chosen.
• Auto-Saving: How auto-save files are made; how their names are chosen.
• Reverting: revert-buffer, and how to customize what it does.

Backup Files

• Making Backups: How Emacs makes backup files, and when.
• Rename or Copy: Two alternatives: renaming the old file or copying it.
• Numbered Backups: Keeping multiple backups for each source file.
• Backup Names: How backup file names are computed; customization.

Buffers

• Buffer Basics: What is a buffer?
• Current Buffer: Designating a buffer as current so that primitives will access its contents.
• Buffer Names: Accessing and changing buffer names.
• Buffer File Name: The buffer file name indicates which file is visited.
• Buffer Modification: A buffer is modified if it needs to be saved.
• Modification Time: Determining whether the visited file was changed ``behind Emacs's back''.
• Read Only Buffers: Modifying text is not allowed in a read-only buffer.
• The Buffer List: How to look at all the existing buffers.
• Creating Buffers: Functions that create buffers.
• Killing Buffers: Buffers exist until explicitly killed.
• Indirect Buffers: An indirect buffer shares text with some other buffer.
• Swapping Text: Swapping text between two buffers.
• Buffer Gap: The gap in the buffer.

Windows

• Basic Windows: Basic information on using windows.
• Splitting Windows: Splitting one window into two windows.
• Deleting Windows: Deleting a window gives its space to other windows.
• Selecting Windows: The selected window is the one that you edit in.
• Cyclic Window Ordering: Moving around the existing windows.
• Buffers and Windows: Each window displays the contents of a buffer.
• Displaying Buffers: Higher-level functions for displaying a buffer and choosing a window for it.
• Choosing Window: How to choose a window for displaying a buffer.
• Dedicated Windows: How to avoid displaying another buffer in a specific window.
• Window Point: Each window has its own location of point.
• Window Start and End: Buffer positions indicating which text is on-screen in a window.
• Textual Scrolling: Moving text up and down through the window.
• Vertical Scrolling: Moving the contents up and down on the window.
• Horizontal Scrolling: Moving the contents sideways on the window.
• Size of Window: Accessing the size of a window.
• Resizing Windows: Changing the size of a window.
• Coordinates and Windows: Converting coordinates to windows.
• Window Tree: The layout and sizes of all windows in a frame.
• Window Configurations: Saving and restoring the state of the screen.
• Window Parameters: Associating additional information with windows.
• Window Hooks: Hooks for scrolling, window size changes, redisplay going past a certain point, or window configuration changes.

Frames

• Creating Frames: Creating additional frames.
• Multiple Terminals: Displaying on several different devices.
• Frame Parameters: Controlling frame size, position, font, etc.
• Terminal Parameters: Parameters common for all frames on terminal.
• Frame Titles: Automatic updating of frame titles.
• Deleting Frames: Frames last until explicitly deleted.
• Finding All Frames: How to examine all existing frames.
• Frames and Windows: A frame contains windows; display of text always works through windows.
• Minibuffers and Frames: How a frame finds the minibuffer to use.
• Input Focus: Specifying the selected frame.
• Visibility of Frames: Frames may be visible or invisible, or icons.
• Raising and Lowering: Raising a frame makes it hide other windows; lowering it makes the others hide it.
• Frame Configurations: Saving the state of all frames.
• Mouse Tracking: Getting events that say when the mouse moves.
• Mouse Position: Asking where the mouse is, or moving it.
• Pop-Up Menus: Displaying a menu for the user to select from.
• Dialog Boxes: Displaying a box to ask yes or no.
• Pointer Shape: Specifying the shape of the mouse pointer.
• Window System Selections: Transferring text to and from other X clients.
• Drag and Drop: Internals of Drag-and-Drop implementation.
• Color Names: Getting the definitions of color names.
• Text Terminal Colors: Defining colors for text-only terminals.
• Resources: Getting resource values from the server.
• Display Feature Testing: Determining the features of a terminal.

Frame Parameters

• Parameter Access: How to change a frame's parameters.
• Initial Parameters: Specifying frame parameters when you make a frame.
• Window Frame Parameters: List of frame parameters for window systems.
• Size and Position: Changing the size and position of a frame.
• Geometry: Parsing geometry specifications.

Window Frame Parameters

• Basic Parameters: Parameters that are fundamental.
• Position Parameters: The position of the frame on the screen.
• Size Parameters: Frame's size.
• Layout Parameters: Size of parts of the frame, and enabling or disabling some parts.
• Buffer Parameters: Which buffers have been or should be shown.
• Management Parameters: Communicating with the window manager.
• Cursor Parameters: Controlling the cursor appearance.
• Font and Color Parameters: Fonts and colors for the frame text.

Positions

• Point: The special position where editing takes place.
• Motion: Changing point.
• Excursions: Temporary motion and buffer changes.
• Narrowing: Restricting editing to a portion of the buffer.

Motion

• Character Motion: Moving in terms of characters.
• Word Motion: Moving in terms of words.
• Buffer End Motion: Moving to the beginning or end of the buffer.
• Text Lines: Moving in terms of lines of text.
• Screen Lines: Moving in terms of lines as displayed.
• List Motion: Moving by parsing lists and sexps.
• Skipping Characters: Skipping characters belonging to a certain set.

Markers

• Overview of Markers: The components of a marker, and how it relocates.
• Predicates on Markers: Testing whether an object is a marker.
• Creating Markers: Making empty markers or markers at certain places.
• Information from Markers: Finding the marker's buffer or character position.
• Marker Insertion Types: Two ways a marker can relocate when you insert where it points.
• Moving Markers: Moving the marker to a new buffer or position.
• The Mark: How "the mark" is implemented with a marker.
• The Region: How to access "the region".

Text

• Near Point: Examining text in the vicinity of point.
• Buffer Contents: Examining text in a general fashion.
• Comparing Text: Comparing substrings of buffers.
• Insertion: Adding new text to a buffer.
• Commands for Insertion: User-level commands to insert text.
• Deletion: Removing text from a buffer.
• User-Level Deletion: User-level commands to delete text.
• The Kill Ring: Where removed text sometimes is saved for later use.
• Undo: Undoing changes to the text of a buffer.
• Maintaining Undo: How to enable and disable undo information. How to control how much information is kept.
• Filling: Functions for explicit filling.
• Margins: How to specify margins for filling commands.
• Adaptive Fill: Adaptive Fill mode chooses a fill prefix from context.
• Auto Filling: How auto-fill mode is implemented to break lines.
• Sorting: Functions for sorting parts of the buffer.
• Columns: Computing horizontal positions, and using them.
• Indentation: Functions to insert or adjust indentation.
• Case Changes: Case conversion of parts of the buffer.
• Text Properties: Assigning Lisp property lists to text characters.
• Substitution: Replacing a given character wherever it appears.
• Transposition: Swapping two portions of a buffer.
• Registers: How registers are implemented. Accessing the text or position stored in a register.
• Base 64: Conversion to or from base 64 encoding.
• MD5 Checksum: Compute the MD5 "message digest"/"checksum".
• Atomic Changes: Installing several buffer changes "atomically".
• Change Hooks: Supplying functions to be run when text is changed.

The Kill Ring

• Kill Ring Concepts: What text looks like in the kill ring.
• Kill Functions: Functions that kill text.
• Yanking: How yanking is done.
• Yank Commands: Commands that access the kill ring.
• Low-Level Kill Ring: Functions and variables for kill ring access.
• Internals of Kill Ring: Variables that hold kill ring data.

Indentation

• Primitive Indent: Functions used to count and insert indentation.
• Mode-Specific Indent: Customize indentation for different modes.
• Region Indent: Indent all the lines in a region.
• Relative Indent: Indent the current line based on previous lines.
• Indent Tabs: Adjustable, typewriter-like tab stops.
• Motion by Indent: Move to first non-blank character.

Text Properties

• Examining Properties: Looking at the properties of one character.
• Changing Properties: Setting the properties of a range of text.
• Property Search: Searching for where a property changes value.
• Special Properties: Particular properties with special meanings.
• Format Properties: Properties for representing formatting of text.
• Sticky Properties: How inserted text gets properties from neighboring text.
• Lazy Properties: Computing text properties in a lazy fashion only when text is examined.
• Clickable Text: Using text properties to make regions of text do something when you click on them.
• Fields: The field property defines fields within the buffer.
• Not Intervals: Why text properties do not use Lisp-visible text intervals.

Non-ASCII Characters

• Text Representations: How Emacs represents text.
• Converting Representations: Converting unibyte to multibyte and vice versa.
• Selecting a Representation: Treating a byte sequence as unibyte or multi.
• Character Codes: How unibyte and multibyte relate to codes of individual characters.
• Character Properties: Character attributes that define their behavior and handling.
• Character Sets: The space of possible character codes is divided into various character sets.
• Scanning Charsets: Which character sets are used in a buffer?
• Translation of Characters: Translation tables are used for conversion.
• Coding Systems: Coding systems are conversions for saving files.
• Input Methods: Input methods allow users to enter various non-ASCII characters without special keyboards.
• Locales: Interacting with the POSIX locale.

Coding Systems

• Coding System Basics: Basic concepts.
• Encoding and I/O: How file I/O functions handle coding systems.
• Lisp and Coding Systems: Functions to operate on coding system names.
• User-Chosen Coding Systems: Asking the user to choose a coding system.
• Default Coding Systems: Controlling the default choices.
• Specifying Coding Systems: Requesting a particular coding system for a single file operation.
• Explicit Encoding: Encoding or decoding text without doing I/O.
• Terminal I/O Encoding: Use of encoding for terminal I/O.
• MS-DOS File Types: How DOS "text" and "binary" files relate to coding systems.

Searching and Matching

• String Search: Search for an exact match.
• Searching and Case: Case-independent or case-significant searching.
• Regular Expressions: Describing classes of strings.
• Regexp Search: Searching for a match for a regexp.
• POSIX Regexps: Searching POSIX-style for the longest match.
• Match Data: Finding out which part of the text matched, after a string or regexp search.
• Search and Replace: Commands that loop, searching and replacing.
• Standard Regexps: Useful regexps for finding sentences, pages,...

Regular Expressions

• Syntax of Regexps: Rules for writing regular expressions.
• Regexp Example: Illustrates regular expression syntax.
• Regexp Functions: Functions for operating on regular expressions.

Syntax of Regular Expressions

• Regexp Special: Special characters in regular expressions.
• Char Classes: Character classes used in regular expressions.
• Regexp Backslash: Backslash-sequences in regular expressions.

The Match Data

• Replacing Match: Replacing a substring that was matched.
• Simple Match Data: Accessing single items of match data, such as where a particular subexpression started.
• Entire Match Data: Accessing the entire match data at once, as a list.
• Saving Match Data: Saving and restoring the match data.

Syntax Tables

• Syntax Basics: Basic concepts of syntax tables.
• Syntax Descriptors: How characters are classified.
• Syntax Table Functions: How to create, examine and alter syntax tables.
• Syntax Properties: Overriding syntax with text properties.
• Motion and Syntax: Moving over characters with certain syntaxes.
• Parsing Expressions: Parsing balanced expressions using the syntax table.
• Standard Syntax Tables: Syntax tables used by various major modes.
• Syntax Table Internals: How syntax table information is stored.
• Categories: Another way of classifying character syntax.

Syntax Descriptors

• Syntax Class Table: Table of syntax classes.
• Syntax Flags: Additional flags each character can have.

Parsing Expressions

• Motion via Parsing: Motion functions that work by parsing.
• Position Parse: Determining the syntactic state of a position.
• Parser State: How Emacs represents a syntactic state.
• Low-Level Parsing: Parsing across a specified region.
• Control Parsing: Parameters that affect parsing.

Abbrevs and Abbrev Expansion

• Abbrev Mode: Setting up Emacs for abbreviation.
• Abbrev Tables: Creating and working with abbrev tables.
• Defining Abbrevs: Specifying abbreviations and their expansions.
• Abbrev Files: Saving abbrevs in files.
• Abbrev Expansion: Controlling expansion; expansion subroutines.
• Standard Abbrev Tables: Abbrev tables used by various major modes.
• Abbrev Properties: How to read and set abbrev properties. Which properties have which effect.
• Abbrev Table Properties: How to read and set abbrev table properties. Which properties have which effect.

Processes

• Subprocess Creation: Functions that start subprocesses.
• Shell Arguments: Quoting an argument to pass it to a shell.
• Synchronous Processes: Details of using synchronous subprocesses.
• Asynchronous Processes: Starting up an asynchronous subprocess.
• Deleting Processes: Eliminating an asynchronous subprocess.
• Process Information: Accessing run-status and other attributes.
• Input to Processes: Sending input to an asynchronous subprocess.
• Signals to Processes: Stopping, continuing or interrupting an asynchronous subprocess.
• Output from Processes: Collecting output from an asynchronous subprocess.
• Sentinels: Sentinels run when process run-status changes.
• Query Before Exit: Whether to query if exiting will kill a process.
• System Processes: Accessing other processes running on your system.
• Transaction Queues: Transaction-based communication with subprocesses.
• Network: Opening network connections.
• Network Servers: Network servers let Emacs accept net connections.
• Datagrams: UDP network connections.
• Low-Level Network: Lower-level but more general function to create connections and servers.
• Misc Network: Additional relevant functions for network connections.
• Serial Ports: Communicating with serial ports.
• Byte Packing: Using bindat to pack and unpack binary data.

Receiving Output from Processes

• Process Buffers: If no filter, output is put in a buffer.
• Filter Functions: Filter functions accept output from the process.
• Decoding Output: Filters can get unibyte or multibyte strings.
• Accepting Output: How to wait until process output arrives.

Low-Level Network Access

• Network Processes: Using make-network-process.
• Network Options: Further control over network connections.
• Network Feature Testing: Determining which network features work on the machine you are using.

Packing and Unpacking Byte Arrays

• Bindat Spec: Describing data layout.
• Bindat Functions: Doing the unpacking and packing.
• Bindat Examples: Samples of what bindat.el can do for you!

Emacs Display

• Refresh Screen: Clearing the screen and redrawing everything on it.
• Forcing Redisplay: Forcing redisplay.
• Truncation: Folding or wrapping long text lines.
• The Echo Area: Displaying messages at the bottom of the screen.
• Warnings: Displaying warning messages for the user.
• Invisible Text: Hiding part of the buffer text.
• Selective Display: Hiding part of the buffer text (the old way).
• Temporary Displays: Displays that go away automatically.
• Overlays: Use overlays to highlight parts of the buffer.
• Width: How wide a character or string is on the screen.
• Line Height: Controlling the height of lines.
• Faces: A face defines a graphics style for text characters: font, colors, etc.
• Fringes: Controlling window fringes.
• Scroll Bars: Controlling vertical scroll bars.
• Display Property: Enabling special display features.
• Images: Displaying images in Emacs buffers.
• Buttons: Adding clickable buttons to Emacs buffers.
• Abstract Display: Emacs' Widget for Object Collections.
• Blinking: How Emacs shows the matching open parenthesis.
• Usual Display: The usual conventions for displaying nonprinting chars.
• Display Tables: How to specify other conventions.
• Beeping: Audible signal to the user.
• Window Systems: Which window system is being used.

The Echo Area

• Displaying Messages: Explicitly displaying text in the echo area.
• Progress: Informing user about progress of a long operation.
• Logging Messages: Echo area messages are logged for the user.
• Echo Area Customization: Controlling the echo area.

Reporting Warnings

• Warning Basics: Warnings concepts and functions to report them.
• Warning Variables: Variables programs bind to customize their warnings.
• Warning Options: Variables users set to control display of warnings.

Overlays

• Managing Overlays: Creating and moving overlays.
• Overlay Properties: How to read and set properties. What properties do to the screen display.
• Finding Overlays: Searching for overlays.

Faces

• Defining Faces: How to define a face with defface.
• Face Attributes: What is in a face?
• Attribute Functions: Functions to examine and set face attributes.
• Displaying Faces: How Emacs combines the faces specified for a character.
• Face Remapping: Remapping faces to alternative definitions.
• Face Functions: How to define and examine faces.
• Auto Faces: Hook for automatic face assignment.
• Font Selection: Finding the best available font for a face.
• Font Lookup: Looking up the names of available fonts and information about them.
• Fontsets: A fontset is a collection of fonts that handle a range of character sets.
• Low-Level Font: Lisp representation for character display fonts.

Fringes

• Fringe Size/Pos: Specifying where to put the window fringes.
• Fringe Indicators: Displaying indicator icons in the window fringes.
• Fringe Cursors: Displaying cursors in the right fringe.
• Fringe Bitmaps: Specifying bitmaps for fringe indicators.
• Customizing Bitmaps: Specifying your own bitmaps to use in the fringes.
• Overlay Arrow: Display of an arrow to indicate position.

The display Property

• Replacing Specs: Display specs that replace the text.
• Specified Space: Displaying one space with a specified width.
• Pixel Specification: Specifying space width or height in pixels.
• Other Display Specs: Displaying an image; magnifying text; moving it up or down on the page; adjusting the width of spaces within text.
• Display Margins: Displaying text or images to the side of the main text.

Images

• Image Formats: Supported image formats.
• Image Descriptors: How to specify an image for use in :display.
• XBM Images: Special features for XBM format.
• XPM Images: Special features for XPM format.
• GIF Images: Special features for GIF format.
• TIFF Images: Special features for TIFF format.
• PostScript Images: Special features for PostScript format.
• Other Image Types: Various other formats are supported.
• Defining Images: Convenient ways to define an image for later use.
• Showing Images: Convenient ways to display an image once it is defined.
• Image Cache: Internal mechanisms of image display.

Buttons

• Button Properties: Button properties with special meanings.
• Button Types: Defining common properties for classes of buttons.
• Making Buttons: Adding buttons to Emacs buffers.
• Manipulating Buttons: Getting and setting properties of buttons.
• Button Buffer Commands: Buffer-wide commands and bindings for buttons.

Abstract Display

• Abstract Display Functions: Functions in the Ewoc package.
• Abstract Display Example: Example of using Ewoc.

Display Tables

• Display Table Format: What a display table consists of.
• Active Display Table: How Emacs selects a display table to use.
• Glyphs: How to define a glyph, and what glyphs mean.

Operating System Interface

• Starting Up: Customizing Emacs startup processing.
• Getting Out: How exiting works (permanent or temporary).
• System Environment: Distinguish the name and kind of system.
• User Identification: Finding the name and user id of the user.
• Time of Day: Getting the current time.
• Time Conversion: Converting a time from numeric form to calendrical data and vice versa.
• Time Parsing: Converting a time from numeric form to text and vice versa.
• Processor Run Time: Getting the run time used by Emacs.
• Time Calculations: Adding, subtracting, comparing times, etc.
• Timers: Setting a timer to call a function at a certain time.
• Idle Timers: Setting a timer to call a function when Emacs has been idle for a certain length of time.
• Terminal Input: Accessing and recording terminal input.
• Terminal Output: Controlling and recording terminal output.
• Sound Output: Playing sounds on the computer's speaker.
• X11 Keysyms: Operating on key symbols for X Windows.
• Batch Mode: Running Emacs without terminal interaction.
• Session Management: Saving and restoring state with X Session Management.

Starting Up Emacs

• Startup Summary: Sequence of actions Emacs performs at startup.
• Init File: Details on reading the init file.
• Terminal-Specific: How the terminal-specific Lisp file is read.
• Command-Line Arguments: How command-line arguments are processed, and how you can customize them.

Getting Out of Emacs

• Killing Emacs: Exiting Emacs irreversibly.
• Suspending Emacs: Exiting Emacs reversibly.

Terminal Input

• Input Modes: Options for how input is processed.
• Recording Input: Saving histories of recent or all input events.

Tips and Conventions

• Coding Conventions: Conventions for clean and robust programs.
• Key Binding Conventions: Which keys should be bound by which programs.
• Programming Tips: Making Emacs code fit smoothly in Emacs.
• Compilation Tips: Making compiled code run fast.
• Warning Tips: Turning off compiler warnings.
• Documentation Tips: Writing readable documentation strings.
• Comment Tips: Conventions for writing comments.
• Library Headers: Standard headers for library packages.

GNU Emacs Internals

• Building Emacs: How the dumped Emacs is made.
• Pure Storage: A kludge to make preloaded Lisp functions sharable.
• Garbage Collection: Reclaiming space for Lisp objects no longer used.
• Memory Usage: Info about total size of Lisp objects made so far.
• Writing Emacs Primitives: Writing C code for Emacs.
• Object Internals: Data formats of buffers, windows, processes.

Object Internals

• Buffer Internals: Components of a buffer structure.
• Window Internals: Components of a window structure.
• Process Internals: Components of a process structure.