Emacs Lisp Cheat Sheet

Special form

special form has its own rule for which arguments are evaluated

Special Form

Purpose	Forms
Definition	defconst defun defvar
Binding constructs	let let* function
Conditional evaluation	and cond if or
Sequential evaluation	prog1 prog2 progn
Iteration	while function
Syntactic extension	defmacro
Quoting	quote
Assignment	setq setq-default
Nonlocal Exits	catch condition-case unwind-protect
Save	save-current-buffer save-excursion save-restriction save-window-excursion
Other	interactive track-mouse with-output-to-temp-buffer

Standard Library

Number

Emacs supports two numeric data types: integers and floating point numbers

Number related function and Variable

Category	Functions Variable
Integer Basics	most-positive-fixnum most-negative-fixnum
Floating Point Basics	logb float-e float-pi
Type Predicate Test	floatp integerp numberp wholenump zerop
Comparison	= eql /= < <= > >= max min abs
Conversions	float truncate floor ceiling round
Arithmetic Operations	1+ 1- + - * / % mod
Rounding Operations	ffloor fceiling ftruncate fround
Bitwise Operations	lsh ash logand logior logxor lognot
Mathematical Functions	sin cos tan asin acos atan exp log log10 expt sqrt
Random Numbers	random

Character

See String section

String

A string in Emacs Lisp is an array that contains an ordered sequence of characters

String and Character related function and Variable

Category	Functions Variable
Predicates for Strings	stringp string-or-null-p char-or-string-p
Creating Strings	make-string string substring substring-no-properties concat split-string split-string-default-separators
Modifying Strings	store-substring clear-string
Comparison	char-equal string= string-equal string< string-lessp compare-strings assoc-string
Conversion	number-to-string string-to-number char-to-string string-to-char
Formatting Strings	format
Case Conversion	downcase upcase capitalize upcase-initials
The Case Table	case-table-p set-standard-case-table standard-case-table current-case-table set-case-table with-case-table ascii-case-table set-case-syntax-pair set-case-syntax-delims set-case-syntax describe-buffer-case-table

List

Lists are built up from cons cells

List related function and Variable

Category	Functions Variable
List-related Predicates	consp atom listp nlistp null
List Elements	car cdr car-safe cdr-safe pop nth nthcdr last safe-length caar cadr cadr cadr butlast nbutlast
Building Lists	cons list make-list append reverse copy-tree number-sequence
List Variables	push add-to-list add-to-ordered-list
Modifying Lists	setcar setcdr nconc nreverse sort
Sets And Lists	memq delq remq memql member delete remove member-ignore-case delete-dups
Association Lists	assoc rassoc sassq rassq assoc-default copy-alist assq-delete-all rassq-delete-all
Rings	make-ring ring-p ring-size ring-length ring-elements ring-copy ring-empty-p ring-ref ring-insert ring-remove ring-insert-at-beginning

Vector

Vector related function and Variable

Category	Functions Variable
Vector Functions	vectorp vector make-vector vconcat
Bool-vectors	make-bool-vector bool-vector-p

Sequence

sequence type is the union of two other Lisp types: lists and arrays. While array has four types, all one-dimensional: strings, vectors, bool-vectors, char-tables.

Sequence related function and Variable

Category	Functions Variable
Sequence Functions	sequencep length elt copy-sequence
Array Functions	arrayp aref aset fillarray
Char-Tables	make-char-table char-table-p char-table-subtype char-table-parent set-char-table-parent char-table-extra-slot set-char-table-extra-slot char-table-range set-char-table-range map-char-table

Hash Tables

Hash Tables related function and Variable

Category	Functions Variable
Creating Hash	make-hash-table makehash
Hash Access	gethash puthash remhash clrhash maphash
Defining Hash	define-hash-table-test sxhashsxhash
Other Hash	hash-table-p copy-hash-table hash-table-count hash-table-test hash-table-weakness hash-table-rehash-size hash-table-rehash-threshold hash-table-size

Symbols

Symbols related function and Variable

Category	Functions Variable
Predicates for symbols	symbolp
Creating Symbols	symbol-name make-symbol intern intern-soft obarray mapatoms unintern
Property Lists	symbol-plist setplist get put plist-get plist-put lax-plist-get lax-plist-put plist-member

Minibuffer

A minibuffer is a special buffer that Emacs commands use to read arguments more complicated than the single numeric prefix argument.

Minibuffer related function and Variable

Category	Functions Variable
Text from Minibuffer	read-from-minibuffer read-string read-regexp minibuffer-allow-text-properties minibuffer-local-map read-no-blanks-input minibuffer-local-ns-map
Object from Minibuffer	read-minibuffer eval-minibuffer edit-and-eval-command
Minibuffer History	add-to-history history-add-new-input history-length history-delete-duplicates minibuffer-history query-replace-history file-name-history buffer-name-history regexp-history extended-command-history shell-command-history read-expression-history
Basic Completion	try-completion all-completions test-completion completion-boundaries completion-ignore-case completion-regexp-list lazy-completion-table completion-in-region
Minibuffer Completion	completing-read
Completion Commands	minibuffer-completion-table minibuffer-completion-predicate minibuffer-completion-confirm minibuffer-confirm-exit-commands minibuffer-complete-word minibuffer-complete minibuffer-complete-and-exit minibuffer-completion-help display-completion-list completion-auto-help minibuffer-local-completion-map minibuffer-local-must-match-map minibuffer-local-filename-completion-map minibuffer-local-filename-must-match-map
High-Level Completion	read-buffer read-buffer-function read-buffer-completion-ignore-case read-command read-variable read-color
Reading File Names	read-file-name read-file-name-function read-file-name-completion-ignore-case read-directory-name insert-default-directory read-shell-command minibuffer-local-shell-command-map
Completion Styles	completion-styles completion-styles-alist
Programmed Completion	completion-table-dynamic completion-annotate-function
Yes-or-No Queries	y-or-n-p y-or-n-p-with-timeout yes-or-no-p
Multiple Queries	map-y-or-n-p
Reading a Password	read-passwd
Minibuffer Commands	exit-minibuffer self-insert-and-exit previous-history-element next-history-element previous-matching-history-element next-matching-history-element
Minibuffer Contents	minibuffer-prompt minibuffer-prompt-end minibuffer-prompt-width minibuffer-contents minibuffer-contents-no-properties minibuffer-completion-contents delete-minibuffer-contents
Minibuffer Windows	active-minibuffer-window minibuffer-window set-minibuffer-window window-minibuffer-p minibuffer-window-active-p
Recursive Mini	minibuffer-depth enable-recursive-minibuffers
Minibuffer Miscellany	minibufferp minibuffer-setup-hook minibuffer-exit-hook minibuffer-help-form minibuffer-scroll-window minibuffer-selected-window max-mini-window-height

File

File related function and Variable

Category	Functions Variable
Visiting Files	find-file find-file-literally find-file-noselect find-file-other-window find-file-read-only view-file find-file-wildcards find-file-hook find-file-not-found-functions find-file-literally create-file-buffer after-find-file
Saving Buffers	save-buffer save-some-buffers write-file write-file-functions write-contents-functions before-save-hook after-save-hook file-precious-flag require-final-newline
Reading from Files	insert-file-contents insert-file-contents-literally
Writing to Files	append-to-file write-region with-temp-file
File Locks	file-locked-p lock-buffer unlock-buffer ask-user-about-lock
Information about Files	file-exists-p file-readable-p file-executable-p file-writable-p file-accessible-directory-p access-file file-ownership-preserved-p file-newer-than-file-p file-symlink-p file-directory-p file-regular-p file-truename file-chase-links file-modes file-nlinks file-attributes locate-file executable-find
Changing Files	add-name-to-file rename-file copy-file make-symbolic-link delete-file set-file-modes set-default-file-modes default-file-modes read-file-modes file-modes-symbolic-to-number set-file-times
File Names	file-name-directory file-name-nondirectory file-name-sans-versions file-name-extension file-name-sans-extension file-name-absolute-p file-relative-name file-name-as-directory directory-file-name abbreviate-file-name expand-file-name default-directory substitute-in-file-name make-temp-file make-temp-name temporary-file-directory small-temporary-file-directory file-name-all-completions file-name-completion completion-ignored-extensions convert-standard-filename
Contents of Directories	directory-files directory-files-and-attributes file-expand-wildcards insert-directory insert-directory-program
Create/Delete Dirs	make-directory copy-directory delete-directory
Magic File Names	inhibit-file-name-handlers inhibit-file-name-operation find-file-name-handler file-local-copy file-remote-p unhandled-file-name-directory
Format Conversion	format-alist buffer-file-format format-write-file format-find-file format-insert-file buffer-auto-save-file-format write-region-annotate-functions write-region-post-annotation-function after-insert-file-functions

Buffer

buffer is a lisp object containing text to be edited

Buffer related function and Variable

Category	Functions Variable
Basic	bufferp current-buffer set-buffer save-current-buffer with-current-buffer with-temp-buffer
Buffer Names	buffer-name rename-buffer get-buffer generate-new-buffer-name
Buffer File Name	buffer-file-name buffer-file-name buffer-file-truename buffer-file-number get-file-buffer find-buffer-visting set-visted-file-name list-buffers-directory
Buffer Modification	buffer-modified-p set-buffer-modified-p restore-buffer-modified-p not-modified buffer-modified-tick buffer-chars-modified-tick
Buffer Modification Time	verify-visited-file-modtime clear-visited-file-modtime visited-file-modtime set-visited-file-modtime ask-user-about-supersession-threat
Read-Only Buffers	buffer-read-only inhibit-read-only toggle-read-only barf-if-buffer-read-only
Buffer List	buffer-list other-buffer last-buffer bury-buffer unbury-buffer
Creating Buffers	get-buffer-creat generate-new-buffer
Killing Buffers	kill-buffer kill-buffer-query-function kill-buffer-hook buffer-offer-save buffer-save-without-query buffer-live-p
Indirect Buffers	make-indirect-buffer clone-indirect-buffer buffer-base-buffer
Swapping Text Between Two Buffers	buffer-swap-text
Buffer Gap	gap-position gap-size

Text (unfinished)

Text is manipulated through Buffer object with point and marker.

Text related function and Variable

Category	Function Variable
Near Point	char-after char-before following-char preceding-char bobp eobp bolp eolp
Examining Buffer Contents	buffer-substring buffer-substring-no-properties buffer-string filter-buffer-substring filter-buffer-substring-function buffer-substring-filters current-word thing-at-point
Comparing Text	compare-buffer-substrings
Inserting Text	insert insert-before-markers insert-char insert-buffer-substring insert-buffer-substring-no-properties
User-Level Insertion Commands	insert-buffer self-insert-command newline overwrite-mode
Deleting Text	erase-buffer delete-region delete-and-extract-region delete-char delete-backward-char backwar-delete-char-untabify backward-delete-char-untabify-method
User-Level Deletion Commands	delete-horizontal-space delete-indentation fixup-whitespace just-one-space delete-blank-lines