CLJS API

ClojureScript API

Welcome! This is a comprehensive reference for ClojureScript's syntax, standard library, and compiler API. See the Cheatsheet for quick reference

Documentation is versioned and supplemented by curated descriptions,examples, and cross-refs. Community contributions welcome.

Current Version: 1.11.132 | Version Table

Get these docs for Dash under User Contributed downloads.

Syntax

Syntax forms, literals, conventions and patterns.

Literals	number literal \| "" string \| #"" regex \| \ character \| : keyword \| :: keyword \| symbol literal
Special Symbols	true \| false \| nil
Symbolic Values	##NaN \| ##Inf \| ##-Inf
Collections	[] vector \| () list \| {} map \| #{} set \| #:{} namespaced map \| #::{} namespaced map
Commenting	; comment \| #! shebang \| #_ ignore
Function	#() function \| % arg \| & rest
Destructuring	destructure [] \| destructure {}
Conventions	? predicate \| ! impure \| earmuffs \| _ unused \| whitespace \| , comma
Symbol Resolution	. dot \| / namespace slash \| js/ namespace \| ^js \| Math/ namespace
Tagged Literals	# tagged literal \| #js literal \| #inst literal \| #uuid literal \| #queue literal
Quoting	' quote \| ` syntax quote \| ~ unquote \| ~@ unquote splicing \| # auto-gensym
Vars	^ meta \| #' var \| @ deref
Reader Conditionals	#? reader conditional \| #?@ reader conditional splicing
Misc	# dispatch \| #<> unreadable \| #= eval

Compiler Options

Entries	:main \| :modules
Preloads	:preloads \| :browser-repl
Output	:output-to \| :output-dir \| :asset-path \| :fingerprint
Output formatting	:output-wrapper \| :preamble \| :pretty-print \| :print-input-delimiter
Optimization	:optimizations \| :optimize-constants \| :static-fns \| :fn-invoke-direct
Source map	:source-map \| :source-map-asset-path \| :source-map-path \| :source-map-timestamp
Translation	:language-in \| :language-out \| :rewrite-polyfills
Libs	:libs \| :foreign-libs \| :npm-deps \| :install-deps \| :package-json-resolution \| :deps-cmd
Node.js	:target \| :hashbang \| :nodejs-rt
Externs	:externs \| :infer-externs \| :use-only-custom-externs
Names	:rename-prefix \| :rename-prefix-namespace \| :pseudo-names \| :stable-names \| :anon-fn-naming-policy
Cache analysis	:cache-analysis \| :cache-analysis-format
Warnings	:warnings \| :warning-handlers \| :closure-warnings \| :checked-arrays
Elide	:elide-asserts \| :elide-strict
Closure	:closure-defines \| :closure-extra-annotations \| :closure-generate-exports \| :closure-module-roots \| :closure-output-charset \| :closure-property-map-in \| :closure-property-map-out \| :closure-variable-map-in \| :closure-variable-map-out
Spec	:spec-skip-macros
Report	:verbose \| :compiler-stats
Watch	:watch-fn \| :watch-error-fn
Bootstrap	:dump-core
Uncategorized	:aot-cache \| :bundle-cmd \| :ignore-js-module-exts \| :opts-cache \| :parallel-build \| :process-shim \| :recompile-dependents \| :target-fn

REPL Options

cljs.core

core library

Compiled	clojurescript-version \| target
Command Line	command-line-args \| main-cli-fn
Arithmetic	* \| + \| - \| / \| divide \| quot \| rem \| mod \| inc \| dec \| identity
Min/Max	min \| max \| min-key \| max-key
Boolean	and \| or \| not
Equality	= \| not= \| == \| identical? \| IEquiv
Comparison	< \| > \| <= \| >= \| compare \| comparator \| IComparable
Number sign?	pos? \| neg? \| zero?
Integer sign?	pos-int? \| neg-int? \| nat-int?
Integer kind?	integer? \| int? \| odd? \| even?
Double kind?	number? \| double? \| float? \| infinite?
Boolean kind?	boolean? \| false? \| true?
Null?	nil? \| undefined?
Not null?	some?
Any kind?	any?
String kind?	string? \| char?
String	str \| subs
Regex	re-find \| re-matches \| re-pattern \| re-seq \| regexp?
Cast	boolean \| char \| int
Bitwise	bit-and \| bit-and-not \| bit-clear \| bit-count \| bit-flip \| bit-not \| bit-or \| bit-set \| bit-shift-left \| bit-shift-right \| bit-shift-right-zero-fill \| bit-test \| bit-xor \| unsigned-bit-shift-right \| int-rotate-left
REPL results	1 \| 2 \| 3 \| e
REPL load	require \| require-macros \| import \| import-macros \| use \| use-macros \| refer-clojure \| load \| load-file \| load-namespace \| loaded-libs
Exceptions	try \| catch \| finally \| throw
Exception info	ex-info \| ex-message \| ex-data \| ex-cause
Assert	assert \| assert
Transient	transient \| persistent! \| conj! \| pop! \| assoc! \| dissoc! \| disj!
Volatile	volatile! \| vswap! \| vreset! \| volatile?
Atom Ref	atom \| swap! \| reset! \| compare-and-set! \| swap-vals! \| reset-vals! \| set-validator! \| get-validator
Watch	add-watch \| remove-watch \| IWatchable
Delay Ref	delay \| force \| delay?
Deref	deref \| IDeref
Pending	realized? \| IPending
Locking	locking
Metadata	meta \| with-meta \| vary-meta \| reset-meta! \| alter-meta!
Vars	def \| defonce \| goog-define \| declare
Var meta	var \| var? \| exists? \| resolve \| set! \| test
Namespace	ns \| ns*
Namespace meta	ns \| find-ns \| find-ns-obj \| find-macros-ns \| in-ns \| create-ns \| ns-imports \| ns-interns \| ns-interns* \| ns-name \| ns-publics \| ns-unmap \| NS_CACHE
Eval	eval \| eval
Bindings	let \| let* \| letfn \| letfn* \| binding \| with-redefs
If	if \| if-not \| if-some \| if-let
When	when \| when-not \| when-some \| when-first \| when-let
Case	case \| case*
Cond	cond \| condp
Conditional threading	cond-> \| cond->> \| some-> \| some->>
Threading	-> \| ->> \| as->
Wrap	do \| comment \| quote
Nested/Filtered loop	for \| doseq
Recursion	loop \| loop* \| recur \| trampoline
Other loops	while \| dotimes
Lazy	lazy-seq \| lazy-cat
Lazy forcing	doall \| dorun \| run!
Functions	defn \| defn- \| fn \| fn* \| fn? \| apply
Macro	defmacro \| macroexpand \| macroexpand-1 \| gensym
Multimethod	defmulti \| defmethod \| get-method \| methods \| prefer-method \| prefers \| remove-method \| remove-all-methods \| default-dispatch-val \| dispatch-fn
Hierarchy	make-hierarchy \| derive \| underive \| parents \| ancestors \| descendants \| isa?
Protocol	defprotocol \| extend-protocol
Type	deftype \| deftype* \| extend-type
Type meta	type \| type->str \| satisfies? \| instance? \| implements? \| is_proto_ \| PROTOCOL_SENTINEL
Record	defrecord \| defrecord* \| record?
Ad-hoc Instance	reify \| specify \| specify!
Tagged Literal	tagged-literal \| tagged-literal?
Timing	system-time \| time \| simple-benchmark
Time instance	inst-ms \| inst?
Coll content?	contains? \| distinct? \| empty? \| every? \| not-every? \| some \| not-any?
Coll capability?	sequential? \| associative? \| sorted? \| counted? \| reversible? \| seqable? \| indexed? \| iterable?
Coll type	coll? \| seq? \| vector? \| list? \| map? \| set?
Coll capability interfaces	ISequential \| IAssociative \| ISorted \| ICounted \| IReversible \| ISeqable \| IIndexed \| IIterable
Coll type interfaces	ICollection \| ISeq \| IVector \| IList \| IMap \| ISet
Coll->Seq	seq \| cons
JS->Seq	prim-seq \| array-seq
Tree->Seq	tree-seq
Seq->Collection	vec \| set
Args->Collection	list \| list* \| vector \| hash-map \| array-map \| sorted-map \| sorted-map-by \| hash-set \| sorted-set \| sorted-set-by \| obj-map
Count	count \| bounded-count
Head/Tail	first \| second \| next \| rest \| last \| butlast
Head/Tail nested	ffirst \| nnext \| nfirst \| fnext
Nth	nth \| nthnext \| nthrest
Take	take \| take-nth \| take-last \| take-while
Drop	drop \| drop-last \| drop-while
Filter	filter \| filterv \| remove
Keep	keep \| keep-indexed
Map	map \| mapv \| map-indexed \| mapcat \| replace
Combine	concat \| flatten \| merge \| merge-with \| interleave \| interpose
Duplicates	dedupe \| distinct \| frequencies
Partition	partition \| partition-all \| partition-by
Split	split-at \| split-with \| group-by
Rearrange	sort \| sort-by \| shuffle
Collection add	conj \| into \| assoc \| assoc-in
Collection update	update \| update-in
Collection get	get \| get-in \| select-keys \| peek
Collection remove	disj \| dissoc \| pop
Collection clear	empty \| not-empty
Map entries	keys \| vals \| zipmap \| key \| val \| find \| map-entry?
Reverse	rseq \| reverse
Sub	subseq \| rsubseq \| subvec
Repeat	cycle \| repeat \| replicate \| iterate \| range
Derive function	partial \| constantly \| repeatedly \| comp \| complement \| some-fn \| every-pred \| fnil \| juxt \| memoize
Transduce	transduce \| eduction \| into \| sequence
Transduce utils	cat \| halt-when \| completing
Reduce	reduce \| reduce-kv \| reduced \| reduced? \| ensure-reduced \| unreduced \| reduceable? \| reductions
Clone	clone \| cloneable? \| ICloneable
JSON<>EDN	js->clj \| clj->js \| key->js
JS kind?	array? \| object? \| js-fn? \| js-iterable? \| js-symbol? \| uri?
JS array	array \| aget \| aset \| alength \| amap \| areduce \| aclone
JS array others	make-array \| object-array \| to-array \| to-array-2d \| into-array
JS object	js-obj \| js-keys
JS interop	. \| .. \| doto \| memfn \| new
JS arguments	js-arguments \| copy-arguments
JS syntax	js* \| js-comment \| js-debugger \| js-delete \| js-in \| js-inline-comment \| js-invoke \| js-mod \| js-reserved \| js-str \| this-as
Random	rand \| rand-int \| rand-nth \| random-sample
UUID	random-uuid \| uuid \| uuid?
Name create	keyword \| symbol
Name extract	name \| namespace
Name munge	munge \| demunge \| CHAR_MAP \| DEMUNGE_MAP \| DEMUNGE_PATTERN
Name kind?	keyword? \| symbol? \| ident?
Name qualified?	qualified-keyword? \| qualified-symbol? \| qualified-ident?
Name unqualified?	simple-keyword? \| simple-symbol? \| simple-ident?
Name reserved?	special-symbol?
Name identical?	keyword-identical? \| symbol-identical?
Machine-readable printing	pr \| prn
Human-readable printing	print \| println
Machine-readable string	pr-str \| pr-str* \| pr-str-with-opts \| prn-str \| prn-str-with-opts
Human-readable string	print-str \| println-str
Print core	string-print \| newline \| with-out-str \| flush
Print settings	print-dup \| print-err-fn \| print-fn \| print-fn-bodies \| print-length \| print-level \| print-meta \| print-namespace-maps \| print-newline \| print-readably \| flush-on-newline \| out \| set-print-fn! \| set-print-err-fn! \| enable-console-print!
Tap	add-tap \| remove-tap \| tap> \| exec-tap-fn
Hashing	hash \| hash-combine \| hash-keyword \| hash-string \| hash-string* \| hash-ordered-coll \| hash-unordered-coll \| mix-collection-hash \| string-hash-cache \| string-hash-cache-count \| add-to-string-hash-cache
Unchecked	unchecked-add \| unchecked-add-int \| unchecked-byte \| unchecked-char \| unchecked-dec \| unchecked-dec-int \| unchecked-divide-int \| unchecked-double \| unchecked-float \| unchecked-get \| unchecked-inc \| unchecked-inc-int \| unchecked-int \| unchecked-long \| unchecked-multiply \| unchecked-multiply-int \| unchecked-negate \| unchecked-negate-int \| unchecked-remainder-int \| unchecked-set \| unchecked-short \| unchecked-subtract \| unchecked-subtract-int
Coercive	coercive-= \| coercive-boolean \| coercive-not \| coercive-not=
MurmurHash3	m3-C1 \| m3-C2 \| m3-fmix \| m3-hash-int \| m3-hash-unencoded-chars \| m3-mix-H1 \| m3-mix-K1 \| m3-seed
ES6 Iteration	es6-entries-iterator \| es6-iterable \| es6-iterator \| es6-iterator-seq \| es6-set-entries-iterator
Chunk	chunk \| chunk-append \| chunk-buffer \| chunk-cons \| chunk-first \| chunk-next \| chunk-rest
Dummy Cast	byte \| short \| long \| float \| double
Dummy Cast Many	booleans \| chars \| bytes \| shorts \| ints \| longs \| floats \| doubles
Arrays	double-array \| long-array \| int-array
Iters	iter \| array-iter \| nil-iter \| seq-iter \| string-iter
Uncategorized	global \| unchecked-arrays \| unchecked-if \| warn-on-infer \| --destructure-map \| LongImpl \| MODULE_INFOS \| MODULE_URIS \| NaN? \| Throwable->map \| abs \| array-chunk \| array-index-of \| array-list \| bitpos \| caching-hash \| chunked-seq \| chunked-seq? \| equiv-map \| gen-apply-to \| gen-apply-to-simple \| gensym_counter \| hash-double \| hash-long \| ifind? \| ifn? \| iteration \| key-test \| load-file* \| mask \| missing-protocol \| mk-bound-fn \| not-native \| parse-boolean \| parse-double \| parse-long \| parse-uuid \| partitionv \| partitionv-all \| persistent-array-map-seq \| pr-seq-writer \| pr-sequential-writer \| print-map \| print-meta? \| print-prefix-map \| ranged-iterator \| seq-to-map-for-destructuring \| set-from-indexed-seq \| splitv-at \| spread \| transformer-iterator \| truth_ \| unsafe-bit-and \| unsafe-cast \| update-keys \| update-vals \| write-all
Types and Protocols	APersistentVector \| ASeq \| ArrayChunk \| ArrayIter \| ArrayList \| ArrayNode \| ArrayNodeIterator \| ArrayNodeSeq \| Atom \| BitmapIndexedNode \| BitmapIndexedNode.EMPTY \| BlackNode \| Box \| ChunkBuffer \| ChunkedCons \| ChunkedSeq \| Cons \| Cycle \| Delay \| ES6EntriesIterator \| ES6Iterator \| ES6IteratorSeq \| ES6SetEntriesIterator \| Eduction \| Empty \| EmptyList \| ExceptionInfo \| Fn \| HashCollisionNode \| HashMapIter \| HashSetIter \| IAtom \| IChunk \| IChunkedNext \| IChunkedSeq \| IDerefWithTimeout \| IDrop \| IEditableCollection \| IEmptyableCollection \| IEncodeClojure \| IEncodeJS \| IFind \| IFn \| IHash \| IKVReduce \| ILookup \| IMapEntry \| IMeta \| IMultiFn \| INamed \| INext \| IPrintWithWriter \| IRecord \| IReduce \| IReset \| IStack \| ISwap \| ITransientAssociative \| ITransientCollection \| ITransientMap \| ITransientSet \| ITransientVector \| IUUID \| IVolatile \| IWithMeta \| IWriter \| IndexedSeq \| IndexedSeqIterator \| Inst \| IntegerRange \| IntegerRangeChunk \| Iterate \| KeySeq \| Keyword \| LazySeq \| List \| List.EMPTY \| Many \| MapEntry \| MetaFn \| MultiFn \| MultiIterator \| Namespace \| NeverEquiv \| NodeIterator \| NodeSeq \| ObjMap \| ObjMap.EMPTY \| ObjMap.HASHMAP_THRESHOLD \| ObjMap.fromObject \| PersistentArrayMap \| PersistentArrayMap.EMPTY \| PersistentArrayMap.HASHMAP-THRESHOLD \| PersistentArrayMap.createAsIfByAssoc \| PersistentArrayMap.createAsIfByAssocComplexPath \| PersistentArrayMap.createWithCheck \| PersistentArrayMap.fromArray \| PersistentArrayMapIterator \| PersistentArrayMapSeq \| PersistentHashMap \| PersistentHashMap.EMPTY \| PersistentHashMap.createWithCheck \| PersistentHashMap.fromArray \| PersistentHashMap.fromArrays \| PersistentHashSet \| PersistentHashSet.EMPTY \| PersistentHashSet.createAsIfByAssoc \| PersistentHashSet.createWithCheck \| PersistentHashSet.fromArray \| PersistentQueue \| PersistentQueue.EMPTY \| PersistentQueueIter \| PersistentQueueSeq \| PersistentTreeMap \| PersistentTreeMap.EMPTY \| PersistentTreeMapSeq \| PersistentTreeSet \| PersistentTreeSet.EMPTY \| PersistentVector \| PersistentVector.EMPTY \| PersistentVector.EMPTY-NODE \| PersistentVector.fromArray \| RSeq \| Range \| RangeIterator \| RangedIterator \| RecordIter \| RedNode \| Reduced \| Repeat \| SeqIter \| Single \| StringBufferWriter \| StringIter \| Subvec \| Symbol \| TaggedLiteral \| TransformerIterator \| TransformerIterator.create \| TransformerIterator.createMulti \| TransientArrayMap \| TransientHashMap \| TransientHashSet \| TransientVector \| UUID \| ValSeq \| Var \| VectorNode \| Volatile

cljs.js

compile/analyze ClojureScript code at runtime.

cljs.math

cljs.nodejs

nodejs support functions

enable-util-print! | process | require

cljs.pprint

a pretty-printer for printing data structures

Types and Protocols

IPrettyFlush

cljs.reader

a reader to parse text and produce data structures

cljs.repl

macros auto-imported into a ClojureScript REPL

cljs.spec.alpha

Types and Protocols

Spec | Specize

cljs.spec.gen.alpha

Types and Protocols

LazyVar

cljs.spec.test.alpha

cljs.test

a unit-testing framework

Types and Protocols

IAsyncTest

clojure.core.protocols


Types and Protocols	Datafiable \| Navigable

clojure.core.reducers

a library for reduction and parallel folding (parallelism not supported)

append! \| cat \| drop \| filter \| flatten \| fold \| foldcat \| folder \| map \| mapcat \| monoid \| reduce \| reducer \| remove \| take \| take-while
Types and Protocols	Cat \| CollFold