Variables

declare

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

def

Creates and interns a global var with the name of symbol in the current namespace (*ns*) or locates such a var if it alr...

defonce

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

get-validator

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

set-validator!

Sets the validator-fn for an atom. validator-fn must be nil or a side-effect-free fn of one argument, which will be pass...

binding

binding => var-symbol init-expr Creates new bindings for the (already-existing) vars, with the supplied initial values,...

if-let

bindings => binding-form test If test is true, evaluates then with binding-form bound to the value of test, if not, yi...

let

binding => binding-form init-expr binding-form => name, or destructuring-form destructuring-form => map-destructure-form...

when-let

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

meta

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

type

Return x's constructor.

alter-meta!

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

vary-meta

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

with-meta

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

add-tap

Adds f, a fn of one argument, to the tap set. This function will be called with anything sent via tap>. Remember f in or...

add-watch

Adds a watch function to an atom reference. The watch fn must be a fn of 4 args: a key, the reference, its old-state, it...

remove-tap

Remove f from the tap set.

remove-watch

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

tap>

Sends x to any taps. Returns the result of *exec-tap-fn*, a Boolean value.