| slovo | definícia |
thunk
(encz) | thunk, n: |
thunk
(wn) | thunk
n 1: a dull hollow sound; "the basketball made a thunk as it hit
the rim" |
thunk
(foldoc) | thunk
/thuhnk/ 1. "A piece of coding which provides an
address", according to P. Z. Ingerman, who invented thunks in
1961 as a way of binding actual parameters to their formal
definitions in ALGOL 60 procedure calls. If a procedure
is called with an expression in the place of a {formal
parameter}, the compiler generates a thunk which computes the
expression and leaves the address of the result in some
standard location.
2. The term was later generalised to mean an expression,
frozen together with its environment (variable values), for
later evaluation if and when needed (similar to a
"closure"). The process of unfreezing these thunks is
called "forcing".
3. A stubroutine, in an overlay programming environment,
that loads and jumps to the correct overlay.
Compare trampoline.
There are a couple of onomatopoeic myths circulating about the
origin of this term. The most common is that it is the sound
made by data hitting the stack; another holds that the sound
is that of the data hitting an accumulator. Yet another
suggests that it is the sound of the expression being unfrozen
at argument-evaluation time. In fact, according to the
inventors, it was coined after they realised (in the wee hours
after hours of discussion) that the type of an argument in
ALGOL 60 could be figured out in advance with a little
compile-time thought, simplifying the evaluation machinery.
In other words, it had "already been thought of"; thus it was
christened a "thunk", which is "the past tense of "think" at
two in the morning".
4. (Microsoft Windows programming) universal thunk,
generic thunk, flat thunk.
[Jargon File]
(1997-10-11)
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thunk
(jargon) | thunk
/thuhnk/, n.
1. [obs.]“A piece of coding which provides an address:”, according to P. Z.
Ingerman, who invented thunks in 1961 as a way of binding actual parameters
to their formal definitions in Algol-60 procedure calls. If a procedure is
called with an expression in the place of a formal parameter, the compiler
generates a thunk which computes the expression and leaves the address of
the result in some standard location.
2. Later generalized into: an expression, frozen together with its
environment, for later evaluation if and when needed (similar to what in
techspeak is called a closure). The process of unfreezing these thunks is
called forcing.
3. A stubroutine, in an overlay programming environment, that loads and
jumps to the correct overlay. Compare trampoline.
4. Microsoft and IBM have both defined, in their Intel-based systems, a “
16-bit environment” (with bletcherous segment registers and 64K address
limits) and a “32-bit environment” (with flat addressing and semi-real
memory management). The two environments can both be running on the same
computer and OS (thanks to what is called, in the Microsoft world, WOW
which stands for Windows On Windows). MS and IBM have both decided that the
process of getting from 16- to 32-bit and vice versa is called a “thunk”;
for Windows 95, there is even a tool THUNK.EXE called a “thunk compiler”.
5. A person or activity scheduled in a thunklike manner. “It occurred to me
the other day that I am rather accurately modeled by a thunk — I frequently
need to be forced to completion.:” — paraphrased from a plan file.
Historical note: There are a couple of onomatopoeic myths circulating about
the origin of this term. The most common is that it is the sound made by
data hitting the stack; another holds that the sound is that of the data
hitting an accumulator. Yet another suggests that it is the sound of the
expression being unfrozen at argument-evaluation time. In fact, according
to the inventors, it was coined after they realized (in the wee hours after
hours of discussion) that the type of an argument in Algol-60 could be
figured out in advance with a little compile-time thought, simplifying the
evaluation machinery. In other words, it had ‘already been thought of’;
thus it was christened a thunk, which is “the past tense of ‘think’ at two
in the morning”.
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