资料来源 : pyDict
关闭使终止
资料来源 : Webster's Revised Unabridged Dictionary (1913)
Closure \Clo"sure\ (?, 135), n. [Of. closure, L. clausura, fr.
clauedere to shut. See {Close}, v. t.]
1. The act of shutting; a closing; as, the closure of a
chink.
2. That which closes or shuts; that by which separate parts
are fastened or closed.
Without a seal, wafer, or any closure whatever.
--Pope.
3. That which incloses or confines; an inclosure.
O thou bloody prison . . . Within the guilty closure
of thy walls Richard the Second here was hacked to
death. --Shak.
4. A conclusion; an end. [Obs.] --Shak.
5. (Parliamentary Practice) A method of putting an end to
debate and securing an immediate vote upon a measure
before a legislative body. It is similar in effect to the
previous question. It was first introduced into the
British House of Commons in 1882. The French word
{cl[^o]ture} was originally applied to this proceeding.
资料来源 : WordNet®
closure
n 1: approaching a particular destination; a coming closer; a
narrowing of a gap; "the ship's rapid rate of closing
gave them little time to avoid a collision" [syn: {closing}]
2: a rule for limiting or ending debate in a deliberative body
[syn: {cloture}, {gag rule}, {gag law}]
3: a Gestalt principle of organization holding that there is an
innate tendency to perceive incomplete objects as complete
and to close or fill gaps and to perceive asymmetric
stimuli as symmetric [syn: {law of closure}]
4: something settled or resolved; the outcome of decision
making; "the finally reached a settlement with the union";
"they never did achieve a final resolution of their
differences"; "he needed to grieve before he could achieve
a sense of closure" [syn: {settlement}, {resolution}]
5: an obstruction in a pipe or tube; "we had to call a plumber
to clear out the blockage in the drainpipe" [syn: {blockage},
{block}, {occlusion}, {stop}, {stoppage}]
6: the act of blocking [syn: {blockage}, {occlusion}]
7: termination of operations; "they regretted the closure of
the day care center" [syn: {closedown}, {closing}, {shutdown}]
v : terminate debate by calling for a vote; "debate was
closured"; "cloture the discussion" [syn: {cloture}]
资料来源 : Free On-Line Dictionary of Computing
closure
1. In a {reduction system}, a closure is a data
structure that holds an expression and an environment of
variable bindings in which that expression is to be evaluated.
The variables may be local or global. Closures are used to
represent unevaluated expressions when implementing
{functional programming languages} with {lazy evaluation}. In
a real implementation, both expression and environment are
represented by pointers.
A {suspension} is a closure which includes a flag to say
whether or not it has been evaluated. The term "{thunk}" has
come to be synonymous with "closure" but originated outside
{functional programming}.
2. In {domain theory}, given a {partially ordered
set}, D and a subset, X of D, the upward closure of X in D is
the union over all x in X of the sets of all d in D such that
x <= d. Thus the upward closure of X in D contains the
elements of X and any greater element of D. A set is "upward
closed" if it is the same as its upward closure, i.e. any d
greater than an element is also an element. The downward
closure (or "left closure") is similar but with d <= x. A
downward closed set is one for which any d less than an
element is also an element.
("<=" is written in {LaTeX} as {\subseteq} and the upward
closure of X in D is written \uparrow_\{D} X).
(1994-12-16)