impact

n 1: the striking of one body against another

2: a forceful consequence; "the book had an important impact on

my thinking"

3: influencing strongly: "they resented the impingement of

American values on European culture" [syn: {impingement},

{encroachment}]

4: the violent interaction of individuals or groups entering

into combat [syn: {shock}]

v 1: press or wedge together; pack together

2: have an effect upon; "Will the new rules affect me?" [syn: {affect},

{bear upon}, {bear on}, {touch on}, {touch}]

compact

1. (Or "finite", "isolated") In {domain theory}, an element d

of a {cpo} D is compact if and only if, for any {chain} S, a

subset of D,

d <◦ lub S ◦> there exists s in S such that d <◦ s.

I.e. you always reach d (or better) after a finite number of

steps up the chain.

("<◦" is written in {LaTeX} as {\sqsubseteq}).

[{Jargon File}]

(1995-01-13)

2. Of a design, describes the valuable property that it can

all be apprehended at once in one's head. This generally

means the thing created from the design can be used with

greater facility and fewer errors than an equivalent tool that

is not compact. Compactness does not imply triviality or lack

of power; for example, {C} is compact and {Fortran} is not,

but C is more powerful than Fortran. Designs become

non-compact through accreting {feature}s and {cruft} that

don't merge cleanly into the overall design scheme (thus, some

fans of {Classic C} maintain that {ANSI C} is no longer

compact).

(1995-01-13)