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

Hash Tables

Buffer 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

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