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8/10/2019 Clojure Quick Reference ClojureDocs - Community-Powered Cl

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Simple Values

Numbers > Arithmetic

Numbers > Compare

Quickref for Clojure Core

Adapted from Johannes Friestad's excellent quick ref.

Simple Values

Numbers

Arithmetic

+

Returns the sum of nums. (+) returns 0. Does not auto-promote longs, will throw on overflow. See also: +'

-

If no ys are supplied, returns the negation of x, else subtracts the ys from x and returns the result. Does

*

Returns the product of nums. (*) returns 1. Does not auto-promote longs, w ill throw on overflow. See also: *

/

If no denominators are supplied, returns 1/numerator, else returns numerator divided by all ofthe denominat

quot

quot[ient] of dividing numerator by denominator.

rem

remainder of dividing numerator by denominator.

mod

Modulus of num and div. Truncates toward negative infinity.

incReturns a number one greater than num. Does not auto-promote longs, willthrow on overflow. See also: inc'

dec

Returns a number one less than num. Does not auto-promote longs, will throw on overflow. See also: dec'

max

Returns the greatest of the nums.

min

Returns the least of the nums.

with-precision

Sets the precision and rounding mode to be used for BigDecimal operations. Usage: (with-precision 10 (/ 1M

Compare

=

Equality. Returns true if x equals y, false if not. Same as Java x.equals(y) except it also works for nil, a

==

Returns non-nil if nums all have the equivalent value (type-independent), otherwise false

not=

Same as (not (= obj1 obj2))

Returns non-nil if nums are in monotonically decreasing order, otherwise false.


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Numbers > Bitwise Operations

Numbers > Cast

Returns non-nil if nums are in monotonically non-decreasing order, otherwise false.

>=

Returns non-nil if nums are in monotonically non-increasing order, otherwise false.

Bitwise Operations

bit-and

Bitwise and

bit-orBitwise or

bit-xor

Bitwise exclusive or

bit-flip

Flip bit at index n

bit-not

Bitwise complement

bit-clear

Clear bit at index n

bit-set

Set bit at index n

bit-shift-left

Bitwise shift left

bit-shift-right

Bitwise shift right

bit-test

Test bit at index n

Cast

byte

Coerce to byte

short

Coerce to short

int

Coerce to int

long

Coerce to long

float

Coerce to float

double

Coerce to double

bigint

Coerce to BigInt

bigdec

Coerce to BigDecimal

num

Coerce to Number

rationalize

returns the rational value of num

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Numbers > Test

Simple Values

Symbols / Keywords > Create

Symbols / Keywords > Use

Symbols / Keywords > Test

Simple Values

Strings / Characters > Create

Test

nil?

Returns true if x is nil, false otherwise.

identical?

Tests if 2 arguments are the same object

zero?

Returns true if num is zero, else false

pos?

Returns true if num is greater than zero, else false

neg?

Returns true if num is less than zero, else false

even?

Returns true if n is even, throws an exception if n is not an integer

odd?

Returns true if n is odd, throws an exception if n is not an integer

Symbols / Keywords

Create

keyword

Returns a Keyword with the given namespace and name. Do not use : in the keyword strings, it will be added

symbol

Returns a Symbol with the given namespace and name.

Use

name

Returns the name String of a string, symbol or keyword.

intern

Finds or creates a var named by the symbol name in the namespace ns (which can be a symbol or a namespace),

namespace

Returns the namespace String of a symbol or keyword, or nil if not present.

Test

keyword?

Return true if x is a Keyword

symbol?

Return true if x is a Symbol

Strings / Characters

Create

str

With no args, returns the empty string. With one arg x, returns x.toString(). (str nil) returns the empty s

print-str

print to a string, returning it

println-str

println to a string, returning it


http://clojuredocs.org/clojure.core/println-strhttp://clojuredocs.org/clojure.core/print-strhttp://clojuredocs.org/clojure.core/strhttp://clojuredocs.org/clojure.core/symbol_qhttp://clojuredocs.org/clojure.core/keyword_qhttp://clojuredocs.org/clojure.core/namespacehttp://clojuredocs.org/clojure.core/internhttp://clojuredocs.org/clojure.core/namehttp://clojuredocs.org/clojure.core/symbolhttp://clojuredocs.org/clojure.core/keywordhttp://clojuredocs.org/clojure.core/odd_qhttp://clojuredocs.org/clojure.core/even_qhttp://clojuredocs.org/clojure.core/neg_qhttp://clojuredocs.org/clojure.core/pos_qhttp://clojuredocs.org/clojure.core/zero_qhttp://clojuredocs.org/clojure.core/identical_qhttp://clojuredocs.org/clojure.core/nil_q


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Strings / Characters > Use

Strings / Characters > Cast / Test

Simple Values

Regular Expressions > Create

Regular Expressions > Use

Operations

Flow Control > Normal

pr-str

pr to a string, returning it

prn-str

prn to a string, returning it

with-out-str

Evaluates exprs in a context in which *out* is bound to a fresh StringWriter. Returns the string created by

Use

count

Returns the number of items in the collection. (count nil) returns 0. Also works on strings, arrays, and Ja

get

Returns the value mapped to key, not-found or nil if key not present.

subs

Returns the substring of s beginning at start inclusive, and ending at end (defaults to length of string), e

format

Formats a string using java.lang.String.format, see java.util.Formatter for format string syntax

Cast / Test

char

Coerce to char

char?

Return true if x is a Character

string?

Return true if x is a String

Regular Expressions

Create

re-pattern

Returns an instance of java.util.regex.Pattern, for use, e.g. in re-matcher.

re-matcher

Returns an instance of java.util.regex.Matcher, for use, e.g. in re-find.

Use

re-find

Returns the next regex match, if any, of string to pattern, using java.util.regex.Matcher.find(). Uses re-g

re-matches

Returns the match, if any, of string to pattern, using java.util.regex.Matcher.matches(). Uses re-groups to

re-seq

Returns a lazy sequence of successive matches of pattern in string, using java.util.regex.Matcher.find(), ea

re-groups

Returns the groups from the most recent match/find. If there are no nested groups, returns a string of the e

Operations

Flow Control

Normal


http://clojuredocs.org/clojure.core/re-groupshttp://clojuredocs.org/clojure.core/re-seqhttp://clojuredocs.org/clojure.core/re-matcheshttp://clojuredocs.org/clojure.core/re-findhttp://clojuredocs.org/clojure.core/re-matcherhttp://clojuredocs.org/clojure.core/re-patternhttp://clojuredocs.org/clojure.core/string_qhttp://clojuredocs.org/clojure.core/char_qhttp://clojuredocs.org/clojure.core/charhttp://clojuredocs.org/clojure.core/formathttp://clojuredocs.org/clojure.core/subshttp://clojuredocs.org/clojure.core/gethttp://clojuredocs.org/clojure.core/counthttp://clojuredocs.org/clojure.core/with-out-strhttp://clojuredocs.org/clojure.core/prn-strhttp://clojuredocs.org/clojure.core/pr-str


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Flow Control > Exceptional

Flow Control > Delay

if

Evaluates test.

if-not

Evaluates test. If logical false, evaluates and returns then expr, otherwise else expr, if supplied, else n

if-let

bindings => binding-form test If test is true, evaluates then with binding-form bound to the value of te

when

Evaluates test. If logical true, evaluates body in an implicit do.

when-not

Evaluates test. If logical false, evaluates body in an implicit do.

when-let

bindings => binding-form test When test is true, evaluates body with binding-form bound to the value of tes

when-first

bindings => x xs Roughly the same as (when (seq xs) (let [x (first xs)] body)) but xs is evaluated only onc

cond

Takes a set of test/expr pairs. It evaluates each test one at a time. If a test returns logical true, cond

condpTakes a binary predicate, an expression, and a set of clauses. Each clause can take the form of either: t

case

Takes an expression, and a set of clauses. Each clause can take the form of either: test-constant result

do

Evaluates the expressions in order and returns the value of the last. If no expressions are supplied, returns

eval

Evaluates the form data structure (not text!) and returns the result.

loop

Evaluates the exprs in a lexical context in which the symbols in the binding-forms are bound to their respec

recur

Evaluates the exprs in order, then, in parallel, rebinds the bindings of the recursion point to the values of

trampoline

trampoline can be used to convert algorithms requiring mutual recursion without stack consumption. Calls f w

while

Repeatedly executes body while test expression is true. Presumes some side-effect will cause test to become

Exceptional

try

The exprs are evaluated and, if no exceptions occur, the value of the last is returned. If an exception occurs

catch


finally


throw

Evaluates the exprs in order, then, in parallel, rebinds the bindings of the recursion point to the values of

assert

Evaluates expr and throws an exception if it does not evaluate to logical true.

Delay

delay

Takes a body of expressions and yields a Delay object that will invoke the body only the first time it is fo


http://clojuredocs.org/clojure.core/delayhttp://clojuredocs.org/clojure.core/asserthttp://clojuredocs.org/clojure.core/throwhttp://clojuredocs.org/clojure.core/finallyhttp://clojuredocs.org/clojure.core/catchhttp://clojuredocs.org/clojure.core/tryhttp://clojuredocs.org/clojure.core/whilehttp://clojuredocs.org/clojure.core/trampolinehttp://clojuredocs.org/clojure.core/recurhttp://clojuredocs.org/clojure.core/loophttp://clojuredocs.org/clojure.core/evalhttp://clojuredocs.org/clojure.core/dohttp://clojuredocs.org/clojure.core/casehttp://clojuredocs.org/clojure.core/condphttp://clojuredocs.org/clojure.core/condhttp://clojuredocs.org/clojure.core/when-firsthttp://clojuredocs.org/clojure.core/when-lethttp://clojuredocs.org/clojure.core/when-nothttp://clojuredocs.org/clojure.core/whenhttp://clojuredocs.org/clojure.core/if-lethttp://clojuredocs.org/clojure.core/if-nothttp://clojuredocs.org/clojure.core/if


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Flow Control > Function Based

Flow Control > Sequence Based

Flow Control > Laziness

Operations

Type Inspection > Clojure Types

Type Inspection > Java Types

delay?

returns true if x is a Delay created with delay

deref

Also reader macro: @ref/@agent/@var/@atom/@delay/@future/@promise. Within a transaction, returns the in-tran

force

If x is a Delay, returns the (possibly cached) value of its expression, else returns x

Function Based

repeatedly

Takes a function of no args, presumably with side effects, and returns an infinite (or length n if supplied)

iterate

Returns a lazy sequence of x, (f x), (f (f x)) etc. f must be free of side-effects

Sequence Based

dotimes

bindings => name n Repeatedly executes body (presumably for side-effects) with name bound to integers fro

doseq

Repeatedly executes body (presumably for side-effects) with bindings and filtering as provided by "for". Do

for

List comprehension. Takes a vector of one or more binding-form/collection-expr pairs, each followed by zero

Laziness

lazy-seq

Takes a body of expressions that returns an ISeq or nil, and yields a Seqable object that will invoke the bo

lazy-cat

Expands to code which yields a lazy sequence of the concatenation of the supplied colls. Each coll expr is

doallWhen lazy sequences are produced via functions that have side effects, any effects other than those needed t

dorun

When lazy sequences are produced via functions that have side effects, any effects other than those needed t

Type Inspection

Clojure Types

type

Returns the :type metadata of x, or its Class if none

extends?

Returns true if atype extends protocol

satisfies?

Returns true if x satisfies the protocol

Java Types

class

Returns the Class of x

basesReturns the immediate superclass and direct interfaces of c, if any

supers

Returns the immediate and indirect superclasses and interfaces of c, if any


http://clojuredocs.org/clojure.core/supershttp://clojuredocs.org/clojure.core/baseshttp://clojuredocs.org/clojure.core/classhttp://clojuredocs.org/clojure.core/satisfies_qhttp://clojuredocs.org/clojure.core/extends_qhttp://clojuredocs.org/clojure.core/typehttp://clojuredocs.org/clojure.core/dorunhttp://clojuredocs.org/clojure.core/doallhttp://clojuredocs.org/clojure.core/lazy-cathttp://clojuredocs.org/clojure.core/lazy-seqhttp://clojuredocs.org/clojure.core/forhttp://clojuredocs.org/clojure.core/doseqhttp://clojuredocs.org/clojure.core/dotimeshttp://clojuredocs.org/clojure.core/iteratehttp://clojuredocs.org/clojure.core/repeatedlyhttp://clojuredocs.org/clojure.core/forcehttp://clojuredocs.org/clojure.core/derefhttp://clojuredocs.org/clojure.core/delay_q


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Operations

Concurrency > General

Concurrency > Atoms

Concurrency > Refs

class?

Returns true if x is an instance of Class

instance?

Evaluates x and tests if it is an instance of the class c. Returns true or false

isa?

Returns true if (= child parent), or child is directly or indirectly derived from parent, either via a Java

cast

Throws a ClassCastException if x is not a c, else returns x.

Concurrency

General

deref

Also reader macro: @ref/@agent/@var/@atom/@delay/@future/@promise. Within a transaction, returns the in-tran

get-validator

Gets the validator-fn for a var/ref/agent/atom.

set-validator!

Sets the validator-fn for a var/ref/agent/atom. validator-fn must be nil or a side-effect-free fn of one arg

Atoms

atom

Creates and returns an Atom with an initial value of x and zero or more options (in any order): :meta met

swap!

Atomically swaps the value of atom to be: (apply f current-value-of-atom args). Note that f may be called

reset!

Sets the value of atom to newval without regard for the current value. Returns newval.

compare-and-set!

Atomically sets the value of atom to newval if and only if the current value of the atom is identical to old

Refs

ref

Creates and returns a Ref with an initial value of x and zero or more options (in any order): :meta metad

sync

transaction-flags => TBD, pass nil for now Runs the exprs (in an implicit do) in a transaction that encompa

dosync

Runs the exprs (in an implicit do) in a transaction that encompasses exprs and any nested calls. Starts a t

ref-set

Must be called in a transaction. Sets the value of ref. Returns val.

alter

Must be called in a transaction. Sets the in-transaction-value of ref to: (apply fun in-transaction-value

commute

Must be called in a transaction. Sets the in-transaction-value of ref to: (apply fun in-transaction-value

ensure

Must be called in a transaction. Protects the ref from modification by other transactions. Returns the in-t

io!

If an io! block occurs in a transaction, throws an IllegalStateException, else runs body in an implicit do.

ref-history-count

Returns the history count of a ref


http://clojuredocs.org/clojure.core/ref-history-counthttp://clojuredocs.org/clojure.core/io!http://clojuredocs.org/clojure.core/ensurehttp://clojuredocs.org/clojure.core/commutehttp://clojuredocs.org/clojure.core/alterhttp://clojuredocs.org/clojure.core/ref-sethttp://clojuredocs.org/clojure.core/dosynchttp://clojuredocs.org/clojure.core/synchttp://clojuredocs.org/clojure.core/refhttp://clojuredocs.org/clojure.core/compare-and-set!http://clojuredocs.org/clojure.core/reset!http://clojuredocs.org/clojure.core/swap!http://clojuredocs.org/clojure.core/atomhttp://clojuredocs.org/clojure.core/set-validator!http://clojuredocs.org/clojure.core/get-validatorhttp://clojuredocs.org/clojure.core/derefhttp://clojuredocs.org/clojure.core/casthttp://clojuredocs.org/clojure.core/isa_qhttp://clojuredocs.org/clojure.core/instance_qhttp://clojuredocs.org/clojure.core/class_q


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Concurrency > Agents

Concurrency > Futures

ref-max-history

Gets the max-history of a ref, or sets it and returns the ref

ref-min-history

Gets the min-history of a ref, or sets it and returns the ref

Agents

agent

Creates and returns an agent with an initial value of state and zero or more options (in any order): :met

send

Dispatch an action to an agent. Returns the agent immediately. Subsequently, in a thread from a thread pool,

send-off

Dispatch a potentially blocking action to an agent. Returns the agent immediately. Subsequently, in a separa

await

Blocks the current thread (indefinitely!) until all actions dispatched thus far, from this thread or agent,

await-for

Blocks the current thread until all actions dispatched thus far (from this thread or agent) to the agents ha

agent-error

Returns the exception thrown during an asynchronous action of the agent if the agent is failed. Returns nil

restart-agent

When an agent is failed, changes the agent state to new-state and then un-fails the agent so that sends are

shutdown-agents

Initiates a shutdown of the thread pools that back the agent system. Running actions will complete, but no n

*agent*

The agent currently running an action on this thread, else nil

error-handler

Returns the error-handler of agent a, or nil if there is none. See set-error-handler!

set-error-handler!

Sets the error-handler of agent a to handler-fn. If an action being run by the agent throws an exception or

error-mode

Returns the error-mode of agent a. See set-error-mode!

set-error-mode!

Sets the error-mode of agent a to mode-keyword, which must be either :fail or :continue. If an action being

release-pending-sends

Normally, actions sent directly or indirectly during another action are held until the action completes (cha

Futures

future

Takes a body of expressions and yields a future object that will invoke the body in another thread, and will

future-call

Takes a function of no args and yields a future object that will invoke the function in another thread, and

future-done?

Returns true if future f is done

future-cancel

Cancels the future, if possible.

future-cancelled?

Returns true if future f is cancelled

future?

Returns true if x is a future


http://clojuredocs.org/clojure.core/future_qhttp://clojuredocs.org/clojure.core/future-cancelled_qhttp://clojuredocs.org/clojure.core/future-cancelhttp://clojuredocs.org/clojure.core/future-done_qhttp://clojuredocs.org/clojure.core/future-callhttp://clojuredocs.org/clojure.core/futurehttp://clojuredocs.org/clojure.core/release-pending-sendshttp://clojuredocs.org/clojure.core/set-error-mode!http://clojuredocs.org/clojure.core/error-modehttp://clojuredocs.org/clojure.core/set-error-handler!http://clojuredocs.org/clojure.core/error-handlerhttp://clojuredocs.org/clojure.core/*agent*http://clojuredocs.org/clojure.core/shutdown-agentshttp://clojuredocs.org/clojure.core/restart-agenthttp://clojuredocs.org/clojure.core/agent-errorhttp://clojuredocs.org/clojure.core/await-forhttp://clojuredocs.org/clojure.core/awaithttp://clojuredocs.org/clojure.core/send-offhttp://clojuredocs.org/clojure.core/sendhttp://clojuredocs.org/clojure.core/agenthttp://clojuredocs.org/clojure.core/ref-min-historyhttp://clojuredocs.org/clojure.core/ref-max-history


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Concurrency > Thread Local Values

Concurrency > Misc

Functions

General > Create

Thread Local Values

bound-fn

Returns a function defined by the given fntail, which will install the same bindings in effect as in the thr

bound-fn*

Returns a function, which will install the same bindings in effect as in the thread at the time bound-fn* wa

get-thread-bindings

Get a map with the Var/value pairs which is currently in effect for the current thread.

push-thread-bindings

WARNING: This is a low-level function. Prefer high-level macros like binding where ever possible. Takes a

pop-thread-bindings

Pop one set of bindings pushed with push-binding before. It is an error to pop bindings without pushing befo

thread-bound?

Returns true if all of the vars provided as arguments have thread-local bindings. Implies that set!'ing the

Misc

locking

Executes exprs in an implicit do, while holding the monitor of x. Will release the monitor of x in all circu

pcalls

Executes the no-arg fns in parallel, returning a lazy sequence of their values

pvalues

Returns a lazy sequence of the values of the exprs, which are evaluated in parallel

pmap

Like map, except f is applied in parallel. Semi-lazy in that the parallel computation stays ahead of the con

seque

Creates a queued seq on another (presumably lazy) seq s. The queued seq will produce a concrete seq in the b

promiseReturns a promise object that can be read with deref/@, and set, once only, with deliver. Calls to deref/@ p

deliver

Delivers the supplied value to the promise, releasing any pending derefs. A subsequent call to deliver on a

add-watch

Adds a watch function to an agent/atom/var/ref reference. The watch fn must be a fn of 4 args: a key, the re

remove-watch

Removes a watch (set by add-watch) from a reference

Functions

General

Create

fn

params => positional-params* , or positional-params* & next-param positional-param => binding-form next-pa

defn

Same as (def name (fn [params* ] exprs*)) or (def name (fn ([params* ] exprs*)+)) with any doc-string or a

defn-

same as defn, yielding non-public def

definline

Experimental - like defmacro, except defines a named function whose body is the expansion, calls to which ma


http://clojuredocs.org/clojure.core/definlinehttp://clojuredocs.org/clojure.core/defn-http://clojuredocs.org/clojure.core/defnhttp://clojuredocs.org/clojure.core/fnhttp://clojuredocs.org/clojure.core/remove-watchhttp://clojuredocs.org/clojure.core/add-watchhttp://clojuredocs.org/clojure.core/deliverhttp://clojuredocs.org/clojure.core/promisehttp://clojuredocs.org/clojure.core/sequehttp://clojuredocs.org/clojure.core/pmaphttp://clojuredocs.org/clojure.core/pvalueshttp://clojuredocs.org/clojure.core/pcallshttp://clojuredocs.org/clojure.core/lockinghttp://clojuredocs.org/clojure.core/thread-bound_qhttp://clojuredocs.org/clojure.core/pop-thread-bindingshttp://clojuredocs.org/clojure.core/push-thread-bindingshttp://clojuredocs.org/clojure.core/get-thread-bindingshttp://clojuredocs.org/clojure.core/bound-fn*http://clojuredocs.org/clojure.core/bound-fn


10/28

General > Call

General > Test

Functions

Multifunctions > Create

Multifunctions > Inspect and Modify

identity

Returns its argument.

constantly

Returns a function that takes any number of arguments and returns x.

memfn

Expands into code that creates a fn that expects to be passed an object and any args and calls the named ins

comp

Takes a set of functions and returns a fn that is the composition of those fns. The returned fn takes a var

complement

Takes a fn f and returns a fn that takes the same arguments as f, has the same effects, if any, and returns

partial

Takes a function f and fewer than the normal arguments to f, and returns a fn that takes a variable number o

juxt

Takes a set of functions and returns a fn that is the juxtaposition of those fns. The returned fn takes a v

memoize

Returns a memoized version of a referentially transparent function. The memoized version of the function kee

Call

->

Threads the expr through the forms. Inserts x as the second item in the first form, making a list of it if i

->>

Threads the expr through the forms. Inserts x as the last item in the first form, making a list of it if it

apply

Applies fn f to the argument list formed by prepending intervening arguments to args.

Test

fn?

Returns true if x implements Fn, i.e. is an object created via fn.

ifn?

Returns true if x implements IFn. Note that many data structures (e.g. sets and maps) implement IFn

Multifunctions

Create

defmulti

Creates a new multimethod with the associated dispatch function. The docstring and attribute-map are optiona

defmethod

Creates and installs a new method of multimethod associated with dispatch-value.

Inspect and Modify

get-method

Given a multimethod and a dispatch value, returns the dispatch fn that would apply to that value, or nil if

methods

Given a multimethod, returns a map of dispatch values -> dispatch fns

prefer-method

Causes the multimethod to prefer matches of dispatch-val-x over dispatch-val-y when there is a conflict

prefers

Given a multimethod, returns a map of preferred value -> set of other values


http://clojuredocs.org/clojure.core/prefershttp://clojuredocs.org/clojure.core/prefer-methodhttp://clojuredocs.org/clojure.core/methodshttp://clojuredocs.org/clojure.core/get-methodhttp://clojuredocs.org/clojure.core/defmethodhttp://clojuredocs.org/clojure.core/defmultihttp://clojuredocs.org/clojure.core/ifn_qhttp://clojuredocs.org/clojure.core/fn_qhttp://clojuredocs.org/clojure.core/applyhttp://clojuredocs.org/clojure.core/-%3E%3Ehttp://clojuredocs.org/clojure.core/-%3Ehttp://clojuredocs.org/clojure.core/memoizehttp://clojuredocs.org/clojure.core/juxthttp://clojuredocs.org/clojure.core/partialhttp://clojuredocs.org/clojure.core/complementhttp://clojuredocs.org/clojure.core/comphttp://clojuredocs.org/clojure.core/memfnhttp://clojuredocs.org/clojure.core/constantlyhttp://clojuredocs.org/clojure.core/identity


11/28

Functions

Macros > Create

Functions

Java Interop > Objects

Java Interop > Array Creation

remove-method

Removes the method of multimethod associated with dispatch-value.

remove-all-methods

Removes all of the methods of multimethod.

Macros

Create

defmacro

Like defn, but the resulting function name is declared as a macro and will be used as a macro by the compile

macroexpand

Repeatedly calls macroexpand-1 on form until it no longer represents a macro form, then returns it. Note ne

macroexpand-1

If form represents a macro form, returns its expansion, else returns form.

gensym

Returns a new symbol with a unique name. If a prefix string is supplied, the name is prefix# where # is some

Java Interop

Objects

doto

Evaluates x then calls all of the methods and functions with the value of x supplied at the front of the giv

..

form => fieldName-symbol or (instanceMethodName-symbol args*) Expands into a member access (.) of the first

set!

Assignment special form. When the first operand is a field member access form, the assignment is to the corres

Array Creation

make-array

Creates and returns an array of instances of the specified class of the specified dimension(s). Note that a

object-array

Creates an array of objects

boolean-array

Creates an array of booleans

byte-array

Creates an array of bytes

char-array

Creates an array of chars

short-array

Creates an array of shorts

int-array

Creates an array of ints

long-array

Creates an array of longs

float-array

Creates an array of floats

double-array

Creates an array of doubles


http://clojuredocs.org/clojure.core/double-arrayhttp://clojuredocs.org/clojure.core/float-arrayhttp://clojuredocs.org/clojure.core/long-arrayhttp://clojuredocs.org/clojure.core/int-arrayhttp://clojuredocs.org/clojure.core/short-arrayhttp://clojuredocs.org/clojure.core/char-arrayhttp://clojuredocs.org/clojure.core/byte-arrayhttp://clojuredocs.org/clojure.core/boolean-arrayhttp://clojuredocs.org/clojure.core/object-arrayhttp://clojuredocs.org/clojure.core/make-arrayhttp://clojuredocs.org/clojure.core/set!http://clojuredocs.org/clojure.core/_..http://clojuredocs.org/clojure.core/dotohttp://clojuredocs.org/clojure.core/gensymhttp://clojuredocs.org/clojure.core/macroexpand-1http://clojuredocs.org/clojure.core/macroexpandhttp://clojuredocs.org/clojure.core/defmacrohttp://clojuredocs.org/clojure.core/remove-all-methodshttp://clojuredocs.org/clojure.core/remove-method


12/28

Java Interop > Array Use

Java Interop > Casting

aclone

Returns a clone of the Java array. Works on arrays of known types.

to-array

Returns an array of Objects containing the contents of coll, which can be any Collection. Maps to java.util

to-array-2d

Returns a (potentially-ragged) 2-dimensional array of Objects containing the contents of coll, which can be

into-array

Returns an array with components set to the values in aseq. The array's component type is type if provided,

Array Use

aget

Returns the value at the index/indices. Works on Java arrays of all types.

aset

Sets the value at the index/indices. Works on Java arrays of reference types. Returns val.

aset-boolean

Sets the value at the index/indices. Works on arrays of boolean. Returns val.

aset-char

Sets the value at the index/indices. Works on arrays of char. Returns val.

aset-byte

Sets the value at the index/indices. Works on arrays of byte. Returns val.

aset-int

Sets the value at the index/indices. Works on arrays of int. Returns val.

aset-long

Sets the value at the index/indices. Works on arrays of long. Returns val.

aset-short

Sets the value at the index/indices. Works on arrays of short. Returns val.

aset-float

Sets the value at the index/indices. Works on arrays of float. Returns val.

aset-double

Sets the value at the index/indices. Works on arrays of double. Returns val.

alength

Returns the length of the Java array. Works on arrays of all types.

amap

Maps an expression across an array a, using an index named idx, and return value named ret, initialized to a

areduce

Reduces an expression across an array a, using an index named idx, and return value named ret, initialized t

Casting

booleans

Casts to boolean[]

bytes

Casts to bytes[]

chars

Casts to chars[]

ints

Casts to int[]

shorts

Casts to shorts[]


http://clojuredocs.org/clojure.core/shortshttp://clojuredocs.org/clojure.core/intshttp://clojuredocs.org/clojure.core/charshttp://clojuredocs.org/clojure.core/byteshttp://clojuredocs.org/clojure.core/booleanshttp://clojuredocs.org/clojure.core/areducehttp://clojuredocs.org/clojure.core/amaphttp://clojuredocs.org/clojure.core/alengthhttp://clojuredocs.org/clojure.core/aset-doublehttp://clojuredocs.org/clojure.core/aset-floathttp://clojuredocs.org/clojure.core/aset-shorthttp://clojuredocs.org/clojure.core/aset-longhttp://clojuredocs.org/clojure.core/aset-inthttp://clojuredocs.org/clojure.core/aset-bytehttp://clojuredocs.org/clojure.core/aset-charhttp://clojuredocs.org/clojure.core/aset-booleanhttp://clojuredocs.org/clojure.core/asethttp://clojuredocs.org/clojure.core/agethttp://clojuredocs.org/clojure.core/into-arrayhttp://clojuredocs.org/clojure.core/to-array-2dhttp://clojuredocs.org/clojure.core/to-arrayhttp://clojuredocs.org/clojure.core/aclone


13/28

Functions

Proxies > Create

Prox ies > Misc

Collections

Collections > Generic Operations

Collections > Content Tests

longs

Casts to long[]

floats

Casts to float[]

doubles

Casts to double[]

Proxies

Create

proxy

class-and-interfaces - a vector of class names args - a (possibly empty) vector of arguments to the supercl

get-proxy-class

Takes an optional single class followed by zero or more interfaces. If not supplied class defaults to Object

construct-proxy

Takes a proxy class and any arguments for its superclass ctor and creates and returns an instance of the pro

init-proxy

Takes a proxy instance and a map of strings (which must correspond to methods of the proxy superclass/superi

Misc

proxy-mappings

Takes a proxy instance and returns the proxy's fn map.

proxy-super

Use to call a superclass method in the body of a proxy method. Note, expansion captures 'this

update-proxy

Takes a proxy instance and a map of strings (which must correspond to methods of the proxy superclass/superi

Collections

Collections

Generic Operations

count

Returns the number of items in the collection. (count nil) returns 0. Also works on strings, arrays, and Ja

empty

Returns an empty collection of the same category as coll, or nil

not-empty

If coll is empty, returns nil, else coll

into

Returns a new coll consisting of to-coll with all of the items of from-coll conjoined.

conj

conj[oin]. Returns a new collection with the xs 'added'. (conj nil item) returns (item). The 'addition' m

Content Tests

contains?

Returns true if key is present in the given collection, otherwise returns false. Note that for numerically

distinct?

Returns true if no two of the arguments are =


http://clojuredocs.org/clojure.core/distinct_qhttp://clojuredocs.org/clojure.core/contains_qhttp://clojuredocs.org/clojure.core/conjhttp://clojuredocs.org/clojure.core/intohttp://clojuredocs.org/clojure.core/not-emptyhttp://clojuredocs.org/clojure.core/emptyhttp://clojuredocs.org/clojure.core/counthttp://clojuredocs.org/clojure.core/update-proxyhttp://clojuredocs.org/clojure.core/proxy-superhttp://clojuredocs.org/clojure.core/proxy-mappingshttp://clojuredocs.org/clojure.core/init-proxyhttp://clojuredocs.org/clojure.core/construct-proxyhttp://clojuredocs.org/clojure.core/get-proxy-classhttp://clojuredocs.org/clojure.core/proxyhttp://clojuredocs.org/clojure.core/doubleshttp://clojuredocs.org/clojure.core/floatshttp://clojuredocs.org/clojure.core/longs


14/28

Collections > Capabilities

Collections > Type Tests

Collections

Vectors > Create

Vectors > Use

empty?

Returns true if coll has no items - same as (not (seq coll)). Please use the idiom (seq x) rather than (not

every?

Returns true if (pred x) is logical true for every x in coll, else false.

not-every?

Returns false if (pred x) is logical true for every x in coll, else true.

some

Returns the first logical true value of (pred x) for any x in coll, else nil. One common idiom is to use a

not-any?

Returns false if (pred x) is logical true for any x in coll, else true.

Capabilities

sequential?

Returns true if coll implements Sequential

associative?

Returns true if coll implements Associative

sorted?

Returns true if coll implements Sorted

counted?

Returns true if coll implements count in constant time

reversible?

Returns true if coll implements Reversible

Type Tests

coll?

Returns true if x implements IPersistentCollection

seq?

Return true if x implements ISeq

vector?

Return true if x implements IPersistentVector

list?

Returns true if x implements IPersistentList

map?

Return true if x implements IPersistentMap

set?Returns true if x implements IPersistentSet

Vectors

Create

vec

Creates a new vector containing the contents of coll. Java arrays will be aliased and should not be modified

vector

Creates a new vector containing the args.

vector-of

Creates a new vector of a single primitive type t, where t is one of :int :long :float :double :byte :short

Use


http://clojuredocs.org/clojure.core/vector-ofhttp://clojuredocs.org/clojure.core/vectorhttp://clojuredocs.org/clojure.core/vechttp://clojuredocs.org/clojure.core/set_qhttp://clojuredocs.org/clojure.core/map_qhttp://clojuredocs.org/clojure.core/list_qhttp://clojuredocs.org/clojure.core/vector_qhttp://clojuredocs.org/clojure.core/seq_qhttp://clojuredocs.org/clojure.core/coll_qhttp://clojuredocs.org/clojure.core/reversible_qhttp://clojuredocs.org/clojure.core/counted_qhttp://clojuredocs.org/clojure.core/sorted_qhttp://clojuredocs.org/clojure.core/associative_qhttp://clojuredocs.org/clojure.core/sequential_qhttp://clojuredocs.org/clojure.core/not-any_qhttp://clojuredocs.org/clojure.core/somehttp://clojuredocs.org/clojure.core/not-every_qhttp://clojuredocs.org/clojure.core/every_qhttp://clojuredocs.org/clojure.core/empty_q


15/28

Collections

Lists > Create

Lists > Use

Collections

Maps > Create

conj


peek

For a list or queue, same as first, for a vector, same as, but much more efficient than, last. If the collec

pop

For a list or queue, returns a new list/queue without the first item, for a vector, returns a new vector wit

get


assoc

assoc[iate]. When applied to a map, returns a new map of the same (hashed/sorted) type, that contains the

subvec

Returns a persistent vector of the items in vector from start (inclusive) to end (exclusive). If end is not

rseq

Returns, in constant time, a seq of the items in rev (which can be a vector or sorted-map), in reverse order

Lists

Create

list

Creates a new list containing the items.

list*

Creates a new list containing the items prepended to the rest, the last of which will be treated as a sequen

Use

cons

Returns a new seq where x is the first element and seq is the rest.

conj


peek

For a list or queue, same as first, for a vector, same as, but much more efficient than, last. If the collec

pop

For a list or queue, returns a new list/queue without the first item, for a vector, returns a new vector wit

first

Returns the first item in the collection. Calls seq on its argument. If coll is nil, returns nil.

rest

Returns a possibly empty seq of the items after the first. Calls seq on its argument.

Maps

Create

hash-map

keyval => key val Returns a new hash map with supplied mappings. If any keys are equal, they are handled

array-mapConstructs an array-map. If any keys are equal, they are handled as if by repeated uses of assoc.

zipmap

Returns a map with the keys mapped to the corresponding vals.

sorted-map


http://clojuredocs.org/clojure.core/sorted-maphttp://clojuredocs.org/clojure.core/zipmaphttp://clojuredocs.org/clojure.core/array-maphttp://clojuredocs.org/clojure.core/hash-maphttp://clojuredocs.org/clojure.core/resthttp://clojuredocs.org/clojure.core/firsthttp://clojuredocs.org/clojure.core/pophttp://clojuredocs.org/clojure.core/peekhttp://clojuredocs.org/clojure.core/conjhttp://clojuredocs.org/clojure.core/conshttp://clojuredocs.org/clojure.core/list*http://clojuredocs.org/clojure.core/listhttp://clojuredocs.org/clojure.core/rseqhttp://clojuredocs.org/clojure.core/subvechttp://clojuredocs.org/clojure.core/assochttp://clojuredocs.org/clojure.core/gethttp://clojuredocs.org/clojure.core/pophttp://clojuredocs.org/clojure.core/peekhttp://clojuredocs.org/clojure.core/conj


16/28

Maps > Use (Sorted Maps)

Maps > Use

keyval => key val Returns a new sorted map with supplied mappings. If any keys are equal, they are handle

sorted-map-by

keyval => key val Returns a new sorted map with supplied mappings, using the supplied comparator. If any

bean

Takes a Java object and returns a read-only implementation of the map abstraction based upon its JavaBean pr

frequencies

Returns a map from distinct items in coll to the number of times they appear.

Use (Sorted Maps)

assoc


assoc-in

Associates a value in a nested associative structure, where ks is a sequence of keys and v is the new value

dissoc

dissoc[iate]. Returns a new map of the same (hashed/sorted) type, that does not contain a mapping for key(s)

find

Returns the map entry for key, or nil if key not present.

key

Returns the key of the map entry.

val

Returns the value in the map entry.

keys

Returns a sequence of the map's keys, in the same order as (seq map).

vals

Returns a sequence of the map's values, in the same order as (seq map).

getReturns the value mapped to key, not-found or nil if key not present.

get-in

Returns the value in a nested associative structure, where ks is a sequence of keys. Returns nil if the key

update-in

'Updates' a value in a nested associative structure, where ks is a sequence of keys and f is a function that

select-keys

Returns a map containing only those entries in map whose key is in keys

merge

Returns a map that consists of the rest of the maps conj-ed onto the first. If a key occurs in more than on

merge-with

Returns a map that consists of the rest of the maps conj-ed onto the first. If a key occurs in more than on

Use

rseq

Returns, in constant time, a seq of the items in rev (which can be a vector or sorted-map), in reverse order

subseq

sc must be a sorted collection, test(s) one of =. Returns a seq of those entries with keys ek f

subseq

sc must be a sorted collection, test(s) one of =. Returns a seq of those entries with keys ek f

rsubseq

sc must be a sorted collection, test(s) one of =. Returns a reverse seq of those entries with k

rsubseq


http://clojuredocs.org/clojure.core/rsubseqhttp://clojuredocs.org/clojure.core/rsubseqhttp://clojuredocs.org/clojure.core/subseqhttp://clojuredocs.org/clojure.core/subseqhttp://clojuredocs.org/clojure.core/rseqhttp://clojuredocs.org/clojure.core/merge-withhttp://clojuredocs.org/clojure.core/mergehttp://clojuredocs.org/clojure.core/select-keyshttp://clojuredocs.org/clojure.core/update-inhttp://clojuredocs.org/clojure.core/get-inhttp://clojuredocs.org/clojure.core/gethttp://clojuredocs.org/clojure.core/valshttp://clojuredocs.org/clojure.core/keyshttp://clojuredocs.org/clojure.core/valhttp://clojuredocs.org/clojure.core/keyhttp://clojuredocs.org/clojure.core/findhttp://clojuredocs.org/clojure.core/dissochttp://clojuredocs.org/clojure.core/assoc-inhttp://clojuredocs.org/clojure.core/assochttp://clojuredocs.org/clojure.core/frequencieshttp://clojuredocs.org/clojure.core/beanhttp://clojuredocs.org/clojure.core/sorted-map-by


17/28

Collections

Sets > Create

Sets > Use

Collections

Structs > Create

Structs > Use

Collections

Sequences > Create

sc must be a sorted collection, test(s) one of =. Returns a reverse seq of those entries with k

Sets

Create

hash-set

Returns a new hash set with supplied keys. Any equal keys are handled as if by repeated uses of conj.

set

Returns a set of the distinct elements of coll.

sorted-set

Returns a new sorted set with supplied keys. Any equal keys are handled as if by repeated uses of conj.

sorted-set-by

Returns a new sorted set with supplied keys, using the supplied comparator. Any equal keys are handled as i

Use

conj


disj

disj[oin]. Returns a new set of the same (hashed/sorted) type, that does not contain key(s).

get


Structs

Create

defstruct

Same as (def name (create-struct keys...))

create-struct

Returns a structure basis object.

struct

Returns a new structmap instance with the keys of the structure-basis. vals must be supplied for basis keys

struct-map

Returns a new structmap instance with the keys of the structure-basis. keyvals may contain all, some or none

accessor

Returns a fn that, given an instance of a structmap with the basis, returns the value at the key. The key m

Use

get


assoc


Sequences

Create

seq

Returns a seq on the collection. If the collection is empty, returns nil. (seq nil) returns nil. seq also


http://clojuredocs.org/clojure.core/seqhttp://clojuredocs.org/clojure.core/assochttp://clojuredocs.org/clojure.core/gethttp://clojuredocs.org/clojure.core/accessorhttp://clojuredocs.org/clojure.core/struct-maphttp://clojuredocs.org/clojure.core/structhttp://clojuredocs.org/clojure.core/create-structhttp://clojuredocs.org/clojure.core/defstructhttp://clojuredocs.org/clojure.core/gethttp://clojuredocs.org/clojure.core/disjhttp://clojuredocs.org/clojure.core/conjhttp://clojuredocs.org/clojure.core/sorted-set-byhttp://clojuredocs.org/clojure.core/sorted-sethttp://clojuredocs.org/clojure.core/sethttp://clojuredocs.org/clojure.core/hash-set


18/28

Sequences > Use (General)

sequence

Coerces coll to a (possibly empty) sequence, if it is not already one. Will not force a lazy seq. (sequence

repeat

Returns a lazy (infinite!, or length n if supplied) sequence of xs.

replicate

DEPRECATED: Use 'repeat' instead. Returns a lazy seq of n xs.

range

Returns a lazy seq of nums from start (inclusive) to end (exclusive), by step, where start defaults to 0, st

repeatedly

Takes a function of no args, presumably with side effects, and returns an infinite (or length n if supplied)

iterate

Returns a lazy sequence of x, (f x), (f (f x)) etc. f must be free of side-effects

lazy-seq

Takes a body of expressions that returns an ISeq or nil, and yields a Seqable object that will invoke the bo

lazy-cat

Expands to code which yields a lazy sequence of the concatenation of the supplied colls. Each coll expr is

cycleReturns a lazy (infinite!) sequence of repetitions of the items in coll.

interleave

Returns a lazy seq of the first item in each coll, then the second etc.

interpose

Returns a lazy seq of the elements of coll separated by sep

tree-seq

Returns a lazy sequence of the nodes in a tree, via a depth-first walk. branch? must be a fn of one arg tha

xml-seq

A tree seq on the xml elements as per xml/parse

enumeration-seq

Returns a seq on a java.util.Enumeration

iterator-seq

Returns a seq on a java.util.Iterator. Note that most collections providing iterators implement Iterable and

file-seq

A tree seq on java.io.Files

line-seq

Returns the lines of text from rdr as a lazy sequence of strings. rdr must implement java.io.BufferedReader.

resultset-seqCreates and returns a lazy sequence of structmaps corresponding to the rows in the java.sql.ResultSet rs

Use (General)

first

Returns the first item in the collection. Calls seq on its argument. If coll is nil, returns nil.

second

Same as (first (next x))

last

Return the last item in coll, in linear time

rest

Returns a possibly empty seq of the items after the first. Calls seq on its argument.

next

Returns a seq of the items after the first. Calls seq on its argument. If there are no more items, returns


http://clojuredocs.org/clojure.core/nexthttp://clojuredocs.org/clojure.core/resthttp://clojuredocs.org/clojure.core/lasthttp://clojuredocs.org/clojure.core/secondhttp://clojuredocs.org/clojure.core/firsthttp://clojuredocs.org/clojure.core/resultset-seqhttp://clojuredocs.org/clojure.core/line-seqhttp://clojuredocs.org/clojure.core/file-seqhttp://clojuredocs.org/clojure.core/iterator-seqhttp://clojuredocs.org/clojure.core/enumeration-seqhttp://clojuredocs.org/clojure.core/xml-seqhttp://clojuredocs.org/clojure.core/tree-seqhttp://clojuredocs.org/clojure.core/interposehttp://clojuredocs.org/clojure.core/interleavehttp://clojuredocs.org/clojure.core/cyclehttp://clojuredocs.org/clojure.core/lazy-cathttp://clojuredocs.org/clojure.core/lazy-seqhttp://clojuredocs.org/clojure.core/iteratehttp://clojuredocs.org/clojure.core/repeatedlyhttp://clojuredocs.org/clojure.core/rangehttp://clojuredocs.org/clojure.core/replicatehttp://clojuredocs.org/clojure.core/repeathttp://clojuredocs.org/clojure.core/sequence


19/28

Sequences > Use ('Modification')

ffirst

Same as (first (first x))

nfirst

Same as (next (first x))

fnext

Same as (first (next x))

nnext

Same as (next (next x))

nth

Returns the value at the index. get returns nil if index out of bounds, nth throws an exception unless not-f

nthnext

Returns the nth next of coll, (seq coll) when n is 0.

rand-nth

Return a random element of the (sequential) collection. Will have the same performance characteristics as nt

butlast

Return a seq of all but the last item in coll, in linear time

takeReturns a lazy sequence of the first n items in coll, or all items if there are fewer than n.

take-last

Returns a seq of the last n items in coll. Depending on the type of coll may be no better than linear time.

take-nth

Returns a lazy seq of every nth item in coll.

take-while

Returns a lazy sequence of successive items from coll while (pred item) returns true. pred must be free of s

drop

Returns a lazy sequence of all but the first n items in coll.

drop-last

Return a lazy sequence of all but the last n (default 1) items in coll

drop-while

Returns a lazy sequence of the items in coll starting from the first item for which (pred item) returns logi

keep

Returns a lazy sequence of the non-nil results of (f item). Note, this means false return values will be inc

keep-indexed

Returns a lazy sequence of the non-nil results of (f index item). Note, this means false return values will

Use ('Modification')

conj


concat

Returns a lazy seq representing the concatenation of the elements in the supplied colls.

distinct

Returns a lazy sequence of the elements of coll with duplicates removed

group-by

Returns a map of the elements of coll keyed by the result of f on each element. The value at each key will b

partition

Returns a lazy sequence of lists of n items each, at offsets step apart. If step is not supplied, defaults t

partition-all

Returns a lazy sequence of lists like partition, but may include partitions with fewer than n items at the e


http://clojuredocs.org/clojure.core/partition-allhttp://clojuredocs.org/clojure.core/partitionhttp://clojuredocs.org/clojure.core/group-byhttp://clojuredocs.org/clojure.core/distincthttp://clojuredocs.org/clojure.core/concathttp://clojuredocs.org/clojure.core/conjhttp://clojuredocs.org/clojure.core/keep-indexedhttp://clojuredocs.org/clojure.core/keephttp://clojuredocs.org/clojure.core/drop-whilehttp://clojuredocs.org/clojure.core/drop-lasthttp://clojuredocs.org/clojure.core/drophttp://clojuredocs.org/clojure.core/take-whilehttp://clojuredocs.org/clojure.core/take-nthhttp://clojuredocs.org/clojure.core/take-lasthttp://clojuredocs.org/clojure.core/takehttp://clojuredocs.org/clojure.core/butlasthttp://clojuredocs.org/clojure.core/rand-nthhttp://clojuredocs.org/clojure.core/nthnexthttp://clojuredocs.org/clojure.core/nthhttp://clojuredocs.org/clojure.core/nnexthttp://clojuredocs.org/clojure.core/fnexthttp://clojuredocs.org/clojure.core/nfirsthttp://clojuredocs.org/clojure.core/ffirst


20/28

Sequences > Use (Iteration)

Collections

Transients > Create

Transients > Use (General)

partition-by

Applies f to each value in coll, splitting it each time f returns a new value. Returns a lazy seq of parti

split-at

Returns a vector of [(take n coll) (drop n coll)]

split-with

Returns a vector of [(take-while pred coll) (drop-while pred coll)]

filter

Returns a lazy sequence of the items in coll for which (pred item) returns true. pred must be free of side-e

remove

Returns a lazy sequence of the items in coll for which (pred item) returns false. pred must be free of side-

replace

Given a map of replacement pairs and a vector/collection, returns a vector/seq with any elements = a key in

shuffle

Return a random permutation of coll

Use (Iteration)

for


doseq


map

Returns a lazy sequence consisting of the result of applying f to the set of first items of each coll, follo

map-indexed

Returns a lazy sequence consisting of the result of applying f to 0 and the first item of coll, followed by

mapcat

Returns the result of applying concat to the result of applying map to f and colls. Thus function f should

reduce

f should be a function of 2 arguments. If val is not supplied, returns the result of applying f to the first

reductions

Returns a lazy seq of the intermediate values of the reduction (as per reduce) of coll by f, starting with i

max-key

Returns the x for which (k x), a number, is greatest.

min-key

Returns the x for which (k x), a number, is least.

doall


dorun


Transients

Create

transient

Returns a new, transient version of the collection, in constant time.

persistent!

Returns a new, persistent version of the transient collection, in constant time. The transient collection ca

Use (General)


http://clojuredocs.org/clojure.core/persistent!http://clojuredocs.org/clojure.core/transienthttp://clojuredocs.org/clojure.core/dorunhttp://clojuredocs.org/clojure.core/doallhttp://clojuredocs.org/clojure.core/min-keyhttp://clojuredocs.org/clojure.core/max-keyhttp://clojuredocs.org/clojure.core/reductionshttp://clojuredocs.org/clojure.core/reducehttp://clojuredocs.org/clojure.core/mapcathttp://clojuredocs.org/clojure.core/map-indexedhttp://clojuredocs.org/clojure.core/maphttp://clojuredocs.org/clojure.core/doseqhttp://clojuredocs.org/clojure.core/forhttp://clojuredocs.org/clojure.core/shufflehttp://clojuredocs.org/clojure.core/replacehttp://clojuredocs.org/clojure.core/removehttp://clojuredocs.org/clojure.core/filterhttp://clojuredocs.org/clojure.core/split-withhttp://clojuredocs.org/clojure.core/split-athttp://clojuredocs.org/clojure.core/partition-by


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Transients > Use ('Modification')

Transients > Use (Iteration)

conj!

Adds x to the transient collection, and return coll. The 'addition' may happen at different 'places' dependi

pop!

Removes the last item from a transient vector. If the collection is empty, throws an exception. Returns coll

assoc!

When applied to a transient map, adds mapping of key(s) to val(s). When applied to a transient vector, sets

dissoc!

Returns a transient map that doesn't contain a mapping for key(s).

disj!

disj[oin]. Returns a transient set of the same (hashed/sorted) type, that does not contain key(s).

Use ('Modification')

conj


concat

Returns a lazy seq representing the concatenation of the elements in the supplied colls.

distinct

Returns a lazy sequence of the elements of coll with duplicates removed

group-by

Returns a map of the elements of coll keyed by the result of f on each element. The value at each key will b

partition

Returns a lazy sequence of lists of n items each, at offsets step apart. If step is not supplied, defaults t

partition-all

Returns a lazy sequence of lists like partition, but may include partitions with fewer than n items at the e

partition-by

Applies f to each value in coll, splitting it each time f returns a new value. Returns a lazy seq of parti

split-at

Returns a vector of [(take n coll) (drop n coll)]

split-with

Returns a vector of [(take-while pred coll) (drop-while pred coll)]

filter

Returns a lazy sequence of the items in coll for which (pred item) returns true. pred must be free of side-e

remove

Returns a lazy sequence of the items in coll for which (pred item) returns false. pred must be free of side-

replace

Given a map of replacement pairs and a vector/collection, returns a vector/seq with any elements = a key in

shuffle

Return a random permutation of coll

Use (Iteration)

for


doseq


map

Returns a lazy sequence consisting of the result of applying f to the set of first items of each coll, follo

map-indexed

Returns a lazy sequence consisting of the result of applying f to 0 and the first item of coll, followed by


http://clojuredocs.org/clojure.core/map-indexedhttp://clojuredocs.org/clojure.core/maphttp://clojuredocs.org/clojure.core/doseqhttp://clojuredocs.org/clojure.core/forhttp://clojuredocs.org/clojure.core/shufflehttp://clojuredocs.org/clojure.core/replacehttp://clojuredocs.org/clojure.core/removehttp://clojuredocs.org/clojure.core/filterhttp://clojuredocs.org/clojure.core/split-withhttp://clojuredocs.org/clojure.core/split-athttp://clojuredocs.org/clojure.core/partition-byhttp://clojuredocs.org/clojure.core/partition-allhttp://clojuredocs.org/clojure.core/partitionhttp://clojuredocs.org/clojure.core/group-byhttp://clojuredocs.org/clojure.core/distincthttp://clojuredocs.org/clojure.core/concathttp://clojuredocs.org/clojure.core/conjhttp://clojuredocs.org/clojure.core/disj!http://clojuredocs.org/clojure.core/dissoc!http://clojuredocs.org/clojure.core/assoc!http://clojuredocs.org/clojure.core/pop!http://clojuredocs.org/clojure.core/conj!


22/28

Code Structure

Variables > Create

Variables > Use

Variables > Inspect

mapcat

Returns the result of applying concat to the result of applying map to f and colls. Thus function f should

reduce

f should be a function of 2 arguments. If val is not supplied, returns the result of applying f to the first

reductions

Returns a lazy seq of the intermediate values of the reduction (as per reduce) of coll by f, starting with i

max-key

Returns the x for which (k x), a number, is greatest.

min-key

Returns the x for which (k x), a number, is least.

doall


dorun


Code Structure

Variables

Create

def

Creates and interns or locates a global var with the name of symbol and a namespace of the value of the curren

defonce

defs name to have the root value of the expr iff the named var has no root value, else expr is unevaluated

intern

Finds or creates a var named by the symbol name in the namespace ns (which can be a symbol or a namespace),

declare

defs the supplied var names with no bindings, useful for making forward declarations.

Use

set!

Assignment special form. When the first operand is a field member access form, the assignment is to the corres

alter-var-root

Atomically alters the root binding of var v by applying f to its current value plus any args

bindingbinding => var-symbol init-expr Creates new bindings for the (already-existing) vars, with the supplied i

with-bindings

Takes a map of Var/value pairs. Installs for the given Vars the associated values as thread-local bindings.

with-bindings*

Takes a map of Var/value pairs. Installs for the given Vars the associated values as thread-local bindings.

with-local-vars

varbinding=> symbol init-expr Executes the exprs in a context in which the symbols are bound to vars with

letfn

fnspec ==> (fname [params*] exprs) or (fname ([params*] exprs)+) Takes a vector of function specs and a bod

gensym

Returns a new symbol with a unique name. If a prefix string is supplied, the name is prefix# where # is some

Inspect


http://clojuredocs.org/clojure.core/gensymhttp://clojuredocs.org/clojure.core/letfnhttp://clojuredocs.org/clojure.core/with-local-varshttp://clojuredocs.org/clojure.core/with-bindings*http://clojuredocs.org/clojure.core/with-bindingshttp://clojuredocs.org/clojure.core/bindinghttp://clojuredocs.org/clojure.core/alter-var-roothttp://clojuredocs.org/clojure.core/set!http://clojuredocs.org/clojure.core/declarehttp://clojuredocs.org/clojure.core/internhttp://clojuredocs.org/clojure.core/defoncehttp://clojuredocs.org/clojure.core/defhttp://clojuredocs.org/clojure.core/dorunhttp://clojuredocs.org/clojure.core/doallhttp://clojuredocs.org/clojure.core/min-keyhttp://clojuredocs.org/clojure.core/max-keyhttp://clojuredocs.org/clojure.core/reductionshttp://clojuredocs.org/clojure.core/reducehttp://clojuredocs.org/clojure.core/mapcat


23/28

Code Structure

Namespaces > Create & Delete

Namespaces > Inspect

var

The symbol must resolve to a var, and the Var object itself (not its value) is returned. The reader macro #'x

find-var

Returns the global var named by the namespace-qualified symbol, or nil if no var with that name.

var-get

Gets the value in the var object

var?

Returns true if v is of type clojure.lang.Var

bound?

Returns true if all of the vars provided as arguments have any bound value, root or thread-local. Implies t

resolve

same as (ns-resolve *ns* symbol) or (ns-resolve *ns* &env symbol)

ns-resolve

Returns the var or Class to which a symbol will be resolved in the namespace (unless found in the environmen

special-symbol?

Returns true if s names a special form

Namespaces

Create & Delete

ns

Sets *ns* to the namespace named by name (unevaluated), creating it if needed. references can be zero or mo

create-ns

Create a new namespace named by the symbol if one doesn't already exist, returns it or the already-existing

remove-ns

Removes the namespace named by the symbol. Use with caution. Cannot be used to remove the clojure namespace.

Inspect

*ns*

A clojure.lang.Namespace object representing the current namespace.

ns-name

Returns the name of the namespace, a symbol.

all-ns

Returns a sequence of all namespaces.

the-nsIf passed a namespace, returns it. Else, when passed a symbol, returns the namespace named by it, throwing a

find-ns

Returns the namespace named by the symbol or nil if it doesn't exist.

ns-publics

Returns a map of the public intern mappings for the namespace.

ns-interns

Returns a map of the intern mappings for the namespace.

ns-refers

Returns a map of the refer mappings for the namespace.

ns-aliases

Returns a map of the aliases for the namespace.

ns-imports

Returns a map of the import mappings for the namespace.


http://clojuredocs.org/clojure.core/ns-importshttp://clojuredocs.org/clojure.core/ns-aliaseshttp://clojuredocs.org/clojure.core/ns-refershttp://clojuredocs.org/clojure.core/ns-internshttp://clojuredocs.org/clojure.core/ns-publicshttp://clojuredocs.org/clojure.core/find-nshttp://clojuredocs.org/clojure.core/the-nshttp://clojuredocs.org/clojure.core/all-nshttp://clojuredocs.org/clojure.core/ns-namehttp://clojuredocs.org/clojure.core/*ns*http://clojuredocs.org/clojure.core/remove-nshttp://clojuredocs.org/clojure.core/create-nshttp://clojuredocs.org/clojure.core/nshttp://clojuredocs.org/clojure.core/special-symbol_qhttp://clojuredocs.org/clojure.core/ns-resolvehttp://clojuredocs.org/clojure.core/resolvehttp://clojuredocs.org/clojure.core/bound_qhttp://clojuredocs.org/clojure.core/var_qhttp://clojuredocs.org/clojure.core/var-gethttp://clojuredocs.org/clojure.core/find-varhttp://clojuredocs.org/clojure.core/var


24/28

Namespaces > Use

Namespaces > Misc

Code Structure

Hierarchies > General

Code Structure

User Defined Types > General

ns-map

Returns a map of all the mappings for the namespace.

Use

in-ns

Sets *ns* to the namespace named by the symbol, creating it if needed.

ns-resolve

Returns the var or Class to which a symbol will be resolved in the namespace (unless found in the environmen

ns-unalias

Removes the alias for the symbol from the namespace.

ns-unmap

Removes the mappings for the symbol from the namespace.

alias

Add an alias in the current namespace to another namespace. Arguments are two symbols: the alias to be used,

Misc

namespace-mungeConvert a Clojure namespace name to a legal Java package name.

Hierarchies

General

make-hierarchy

Creates a hierarchy object for use with derive, isa? etc.

derive

Establishes a parent/child relationship between parent and tag. Parent must be a namespace-qualified symbol

underive

Removes a parent/child relationship between parent and tag. h must be a hierarchy obtained from make-hierarc

parents

Returns the immediate parents of tag, either via a Java type inheritance relationship or a relationship esta

ancestors

Returns the immediate and indirect parents of tag, either via a Java type inheritance relationship or a rela

descendants

Returns the immediate and indirect children of tag, through a relationship established via derive. h must be

isa?Returns true if (= child parent), or child is directly or indirectly derived from parent, either via a Java

User Defined Types

General

defprotocol

A protocol is a named set of named methods and their signatures: (defprotocol AProtocolName ;optional d

defrecord

(defrecord name [fields*] options* specs*) Currently there are no options. Each spec consists of a pr

deftype

(deftype name [fields*] options* specs*) Currently there are no options. Each spec consists of a prot

reify

reify is a macro with the following structure: (reify options* specs*) Currently there are no options.


http://clojuredocs.org/clojure.core/reifyhttp://clojuredocs.org/clojure.core/deftypehttp://clojuredocs.org/clojure.core/defrecordhttp://clojuredocs.org/clojure.core/defprotocolhttp://clojuredocs.org/clojure.core/isa_qhttp://clojuredocs.org/clojure.core/descendantshttp://clojuredocs.org/clojure.core/ancestorshttp://clojuredocs.org/clojure.core/parentshttp://clojuredocs.org/clojure.core/underivehttp://clojuredocs.org/clojure.core/derivehttp://clojuredocs.org/clojure.core/make-hierarchyhttp://clojuredocs.org/clojure.core/namespace-mungehttp://clojuredocs.org/clojure.core/aliashttp://clojuredocs.org/clojure.core/ns-unmaphttp://clojuredocs.org/clojure.core/ns-unaliashttp://clojuredocs.org/clojure.core/ns-resolvehttp://clojuredocs.org/clojure.core/in-nshttp://clojuredocs.org/clojure.core/ns-map


25/28

Code Structure

Metadata > General

Environment

Require / Import > General

Environment

Code > General

extend

Implementations of protocol methods can be provided using the extend construct: (extend AType AProtocol

extend-protocol

Useful when you want to provide several implementations of the same protocol all at once. Takes a single pro

extend-type

A macro that expands into an extend call. Useful when you are supplying the definitions explicitly inline, e

extenders

Returns a collection of the types explicitly extending protocol

Metadata

General

meta

Returns the metadata of obj, returns nil if there is no metadata.

with-meta

Returns an object of the same type and value as obj, with map m as its metadata.

vary-meta

Returns an object of the same type and value as obj, with (apply f (meta obj) args) as its metadata.

reset-meta!

Atomically resets the metadata for a namespace/var/ref/agent/atom

alter-meta!

Atomically sets the metadata for a namespace/var/ref/agent/atom to be: (apply f its-current-meta args) f

Environment

Require / Import

General

use

Like 'require, but also refers to each lib's namespace using clojure.core/refer. Use :use in the ns macro in

require

Loads libs, skipping any that are already loaded. Each argument is either a libspec that identifies a lib, a

import

import-list => (package-symbol class-name-symbols*) For each name in class-name-symbols, adds a mapping fro

refer-clojure

Same as (refer 'clojure.core )

refer

refers to all public vars of ns, subject to filters. filters can include at most one each of: :exclude li

Code

General

*compile-files*

Set to true when compiling files, false otherwise.

*compile-path*

Specifies the directory where 'compile' will write out .class files. This directory must be in the classpath


http://clojuredocs.org/clojure.core/*compile-path*http://clojuredocs.org/clojure.core/*compile-files*http://clojuredocs.org/clojure.core/referhttp://clojuredocs.org/clojure.core/refer-clojurehttp://clojuredocs.org/clojure.core/importhttp://clojuredocs.org/clojure.core/requirehttp://clojuredocs.org/clojure.core/usehttp://clojuredocs.org/clojure.core/alter-meta!http://clojuredocs.org/clojure.core/reset-meta!http://clojuredocs.org/clojure.core/vary-metahttp://clojuredocs.org/clojure.core/with-metahttp://clojuredocs.org/clojure.core/metahttp://clojuredocs.org/clojure.core/extendershttp://clojuredocs.org/clojure.core/extend-typehttp://clojuredocs.org/clojure.core/extend-protocolhttp://clojuredocs.org/clojure.core/extend


26/28

Environment

IO > General

*file*

The path of the file being evaluated, as a String. When there is no file, e.g. in the REPL, the value is no

*warn-on-reflection*

When set to true, the compiler will emit warnings when reflection is needed to resolve Java method calls or

compile

Compiles the namespace named by the symbol lib into a set of classfiles. The source for the lib must be in a

load

Loads Clojure code from resources in classpath. A path is interpreted as classpath-relative if it begins wit

load-file

Sequentially read and evaluate the set of forms contained in the file.

load-reader

Sequentially read and evaluate the set of forms contained in the stream/file

load-string

Sequentially read and evaluate the set of forms contained in the string

read

Reads the next object from stream, which must be an instance of java.io.PushbackReader or some derivee. str

read-stringReads one object from the string s. Note that read-string can execute code (controlled by *read-eval*), a

gen-class

When compiling, generates compiled bytecode for a class with the given package-qualified :name (which, as al

gen-interface

When compiling, generates compiled bytecode for an interface with the given package-qualified :name (which,

loaded-libs

Returns a sorted set of symbols naming the currently loaded libs

test

test [v] finds fn at key :test in var metadata and calls it, presuming failure will throw exception

IO

General

*in*

A java.io.Reader object representing standard input for read operations. Defaults to System/in, wrapped in

*out*

A java.io.Writer object representing standard output for print operations. Defaults to System/out, wrapped

*err*

A java.io.Writer object representing standard error for print operations. Defaults to System/err, wrapped i

print

Prints the object(s) to the output stream that is the current value of *out*. print and println produce out

printf

Prints formatted output, as per format

println

Same as print followed by (newline)

pr

Prints the object(s) to the output stream that is the current value of *out*. Prints the object(s), separat

prn

Same as pr followed by (newline). Observes *flush-on-newline*

print-str

print to a string, returning it


http://clojuredocs.org/clojure.core/print-strhttp://clojuredocs.org/clojure.core/prnhttp://clojuredocs.org/clojure.core/prhttp://clojuredocs.org/clojure.core/printlnhttp://clojuredocs.org/clojure.core/printfhttp://clojuredocs.org/clojure.core/printhttp://clojuredocs.org/clojure.core/*err*http://clojuredocs.org/clojure.core/*out*http://clojuredocs.org/clojure.core/*in*http://clojuredocs.org/clojure.core/testhttp://clojuredocs.org/clojure.core/loaded-libshttp://clojuredocs.org/clojure.core/gen-interfacehttp://clojuredocs.org/clojure.core/gen-classhttp://clojuredocs.org/clojure.core/read-stringhttp://clojuredocs.org/clojure.core/readhttp://clojuredocs.org/clojure.core/load-stringhttp://clojuredocs.org/clojure.core/load-readerhttp://clojuredocs.org/clojure.core/load-filehttp://clojuredocs.org/clojure.core/loadhttp://clojuredocs.org/clojure.core/compilehttp://clojuredocs.org/clojure.core/*warn-on-reflection*http://clojuredocs.org/clojure.core/*file*


27/28

Environment

REPL > General

Environment

println-str

println to a string, returning it

pr-str

pr to a string, returning it

prn-str

prn to a string, returning it

newline

Writes a platform-specific newline to *out*

flush

Flushes the output stream that is the current value of *out*

read-line

Reads the next line from stream that is the current value of *in* .

slurp

Opens a reader on f and reads all its contents, returning a string. See clojure.java.io/reader for a complet

spit

Opposite of slurp. Opens f with writer, writes content, then closes f. Options passed to clojure.java.io/wr

with-in-str

Evaluates body in a context in which *in* is bound to a fresh StringReader initialized with the string s.

with-out-str

Evaluates exprs in a context in which *out* is bound to a fresh StringWriter. Returns the string created by

with-open

bindings => [name init ...] Evaluates body in a try expression with names bound to the values of the init

REPL

General

*1

bound in a repl thread to the most recent value printed

*2

bound in a repl thread to the second most recent value printed

*3

bound in a repl thread to the third most recent value printed

*e

bound in a repl thread to the most recent exception caught by the repl

*print-dup*

When set to logical true, objects will be printed in a way that preserves their type when read in later.

*print-length*

*print-length* controls how many items of each collection the printer will print. If it is bound to logical

*print-level*

*print-level* controls how many levels deep the printer will print nested objects. If it is bound to logical

*print-meta*

If set to logical true, when printing an object, its metadata will also be printed in a form that can be rea

*print-readably*

When set to logical false, strings and characters will be printed with non-alphanumeric characters converted

Misc


http://clojuredocs.org/clojure.core/*print-readably*http://clojuredocs.org/clojure.core/*print-meta*http://clojuredocs.org/clojure.core/*print-level*http://clojuredocs.org/clojure.core/*print-length*http://clojuredocs.org/clojure.core/*print-dup*http://clojuredocs.org/clojure.core/*ehttp://clojuredocs.org/clojure.core/*3http://clojuredocs.org/clojure.core/*2http://clojuredocs.org/clojure.core/*1http://clojuredocs.org/clojure.core/with-openhttp://clojuredocs.org/clojure.core/with-out-strhttp://clojuredocs.org/clojure.core/with-in-strhttp://clojuredocs.org/clojure.core/spithttp://clojuredocs.org/clojure.core/slurphttp://clojuredocs.org/clojure.core/read-linehttp://clojuredocs.org/clojure.core/flushhttp://clojuredocs.org/clojure.core/newlinehttp://clojuredocs.org/clojure.core/prn-strhttp://clojuredocs.org/clojure.core/pr-strhttp://clojuredocs.org/clojure.core/println-str


28/28

Misc > GeneralGeneral

*clojure-version*

The version info for Clojure core, as a map containing :major :minor :incremental and :qualifier keys. Feat

clojure-version

Returns clojure version as a printable string.

*command-line-args*

A sequence of the supplied command line arguments, or nil if none were supplied

time

Evaluates expr and prints the time it took. Returns the value of expr.

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