2d4f3e2ac9
The layer is now redundant, since everything left in "pkgs" is in the "racket-pkgs" category.
19 lines
516 B
Racket
19 lines
516 B
Racket
#lang scribble/doc
|
|
@(require "mz.rkt"
|
|
(for-label racket/undefined))
|
|
|
|
@title[#:tag "undefined"]{Undefined}
|
|
|
|
@note-lib-only[racket/undefined]
|
|
|
|
The constant @racket[undefined] can be used as a placeholder value for
|
|
a value to be installed later, especially for cases where premature
|
|
access of the value is either difficult or impossible to detect or
|
|
prevent.
|
|
|
|
The @racket[undefined] value is always @racket[eq?] to itself.
|
|
|
|
@history[#:added "6.0.0.6"]
|
|
|
|
@defthing[undefined any/c]{The ``undefined'' constant.}
|