Cheat sheet

The core of clove, grouped by what you're trying to do. Point at a name to see how to call it and what it does; click to keep it open. Printable PDF.

Basics

Numbers

Literals	`42` `-1.5` `22/7` `1N` `0xff` `2r1010` `1e9` `##Inf`
Arithmetic	+ - * / quot rem mod inc dec abs max min
Overflow	+' -' *' inc' unchecked-add unchecked-multiply
Compare	= not= == < > <= >= compare
Test	zero? pos? neg? even? odd? number? integer? int? double? ratio? NaN?
Convert	int long double bigint rationalize numerator denominator parse-long parse-double
Random	rand rand-int rand-nth shuffle random-uuid
Bits	bit-and bit-or bit-xor bit-not bit-shift-left bit-shift-right
Math	Math/sqrt Math/pow Math/floor Math/ceil Math/round Math/log Math/sin Math/PI

Strings

Build	str format pr-str prn-str with-out-str str/join
Use	count subs str/split str/split-lines str/index-of str/includes? str/starts-with? str/ends-with?
Search	str/last-index-of re-find
Change	str/upper-case str/lower-case str/capitalize str/trim str/triml str/trimr str/replace str/reverse
Test	string? str/blank? char?
Parse	read-string parse-long parse-double parse-boolean keyword symbol name namespace

Regex

Literal	`#"a+b"`
Match	re-find re-matches re-seq re-groups re-matcher re-pattern
Replace	str/replace str/replace-first

Other scalars

Keywords	keyword keyword? name namespace
Symbols	symbol symbol? gensym
nil and bools	nil? some? true? false? boolean not

Collections

Any collection

Ask	count empty? not-empty seq coll? contains? every? some not-any?
Change	conj into empty
Compare	= identical? distinct? hash
Kind	coll? sequential? associative? sorted? map? vector? list? set? seq? fn?

Transients

Use	transient persistent! conj! assoc! dissoc! pop! disj!

Vectors

Make	`[]` vector vec mapv filterv
Read	get nth peek first last subvec
Change	conj assoc pop update

Lists

Make	`'()` list list*
Read	first rest peek
Change	cons conj pop

Arrays

Use	int-array long-array double-array object-array aget aset alength

Maps

Make	`{}` hash-map array-map sorted-map sorted-map-by zipmap frequencies group-by
Read	get get-in keys vals find select-keys contains?
Change	assoc assoc-in dissoc update update-in merge merge-with
Whole map	update-keys update-vals reduce-kv
Entries	key val

Sets

Make	`#{}` hash-set set sorted-set sorted-set-by
Change	conj disj
clojure.set	set/union set/intersection set/difference set/subset? set/superset? set/rename-keys set/index

Nested data

Paths	get-in assoc-in update-in
Walk	clojure.walk/postwalk clojure.walk/prewalk clojure.walk/keywordize-keys
Diff	clojure.data/diff

Sequences

Make a seq

From data	seq vals keys rseq subseq rsubseq
Generate	range repeat repeatedly iterate cycle lazy-seq
Combine	concat interleave interpose

Take part of one

From the front	first second next rest take drop take-while drop-while nthrest
From the back	last butlast take-last drop-last
By value	filter remove keep distinct dedupe
By position	nth take-nth rand-nth

Transform

Each item	map map-indexed keep-indexed mapcat
Reorder	sort sort-by reverse shuffle
Group	partition partition-all partition-by group-by split-at split-with
Flatten	flatten tree-seq

Consume

Reduce	reduce reductions reduce-kv transduce frequencies
Find	some first filter every? not-every?
Side effects	doseq dorun doall run!

Transducers

Use	transduce into sequence eduction
Compose	comp map filter remove take drop mapcat cat partition-all dedupe
Stop early	reduced reduced? unreduced

Functions

Define

Named	defn defn- defmulti defmethod
Anonymous	fn `#(* % 2)` letfn

Combine

Build	comp partial complement juxt constantly identity fnil memoize every-pred some-fn
Call	apply trampoline

Threading

Thread	-> ->> as-> some-> some->> cond-> cond->> doto

Polymorphism

Protocols	defprotocol extend-protocol extend-type satisfies? reify
Types	defrecord deftype instance? type
Multimethods	defmulti defmethod derive isa?

Control

Binding

Local	let if-let when-let if-some when-some letfn
Global	def defonce declare
Dynamic	binding with-redefs

Branching

Two ways	if if-not when when-not
Many ways	cond condp case
Logic	and or not
In order	do

Looping

Loop	loop recur dotimes while
Comprehend	for doseq

Errors

Throw	throw ex-info
Catch	try ex-message ex-data ex-cause
Check	assert

Macros

Define	defmacro gensym
Inspect	macroexpand macroexpand-1
Code as data	quote eval read-string var

Metadata

Use	meta with-meta vary-meta
Literal	`^:private` `^{:doc "…"}`

State and concurrency

Atoms

Use	atom deref reset! swap! swap-vals! reset-vals! compare-and-set!
Watch	add-watch remove-watch set-validator!

Refs and agents

Refs	ref dosync alter commute ref-set ensure
Agents	agent send send-off await agent-error restart-agent

Later

Delay	delay force realized?
Future	future future-done? future-cancel
Promise	promise deliver

Volatiles

Use	volatile! vreset! vswap!

Environment

Namespaces

Declare	ns require in-ns
Look around	ns find-ns all-ns ns-publics resolve

Files and processes

Read	slurp line-seq read-line
Write	spit println print prn printf
Run	sh
Args	args command-line-args

REPL

Look up	doc source dir apropos find-doc
Results	1 2 3 e pst
Debug	dbg time tap> add-tap
Browse	pprint inspect
Skip	comment `#_`

Batteries

Files (fs)

Paths	fs/cwd fs/parent fs/file-name fs/extension fs/temp-dir
Ask	fs/exists? fs/directory? fs/regular-file? fs/list-dir
Change	fs/create-dir fs/copy fs/move fs/delete

Processes (process)

Run	process/sh process/shell process/out process/escape

JSON (json)

Use	json/parse json/write

HTTP (http)

Client	http/get http/post http/request
Server	http/run-server http/serve http/router

Grammars (peg)

Use	peg/match peg/compile peg/find peg/find-all peg/replace peg/replace-all

clove 0.9.0 · https://github.com/alexalemi/clove