<programming, tool> A program that converts another program
	from some {source language} (or {programming language}) to
	{machine language} (object code).  Some compilers output
	{assembly language} which is then converted to {machine
	language} by a separate {assembler}.

	A compiler is distinguished from an assembler by the fact that
	each input statement does not, in general, correspond to a
	single machine instruction or fixed sequence of instructions.
	A compiler may support such features as automatic allocation
	of variables, arbitrary arithmetic expressions, control
	structures such as FOR and WHILE loops, variable {scope},
	input/ouput operations, {higher-order functions} and
	{portability} of source code.

	{AUTOCODER}, written in 1952, was possibly the first primitive
	compiler.  {Laning and Zierler}'s compiler, written in
	1953-1954, was possibly the first true working algebraic
	compiler.

	See also {byte-code compiler}, {native compiler}, {optimising
	compiler}.

	(1994-11-07)

1. <programming> The prototype for an {object} in an
	{object-oriented language}; analogous to a {derived type} in a
	{procedural language}.  A class may also be considered to be a
	set of objects which share a common structure and behaviour.
	The structure of a class is determined by the {class
	variables} which represent the {state} of an object of that
	class and the behaviour is given by a set of {methods}
	associated with the class.

	Classes are related in a {class hierarchy}.  One class may be
	a specialisation (a "{subclass}") of another (one of its
	"{superclasses}") or it may be composed of other classes or it
	may use other classes in a {client-server} relationship.  A
	class may be an {abstract class} or a {concrete class}.

	See also {signature}.

	2. <programming> See {type class}.

	3. <networking> One of three types of {Internet addresses}
	distinguished by their most significant bits.

	3. <language> A language developed by the {Andrew Project}.
	It was one of the first attempts to add {object-oriented}
	features to {C}.

	(1995-05-01)

<operating system, programming> The process of carrying out
	the {instructions} in a computer program by a computer.

	See also {dry run}.

	(1996-05-13)

<language, architecture> (JVM) A specification for software
	which interprets {Java} programs that have been compiled into
	{byte-codes}, and usually stored in a ".class" file.  The JVM
	{instruction set} is {stack}-oriented, with variable
	instruction length.  Unlike some other instruction sets, the
	JVM's supports {object-oriented} programming directly by
	including instructions for object {method} invocation (similar
	to {subroutine} call in other instruction sets).

	The JVM itself is written in {C} and so can be {ported} to run
	on most {platforms}.  It needs {thread} support and {I/O} (for
	{dynamic class loading}).  The Java byte-code is independent
	of the platform.

	There are also some hardware implementations of the JVM.

	{Specification
	(http://www.javasoft.com/docs/books/vmspec/html/VMSpecTOC.doc.html)}.

	{Sun's Java chip
	(http://news.com/News/Item/0,4,9328,00.html)}.

	[Documentation?  Versions?]

	(2000-01-03)

1. <programming> {switch statement}.

	2. <software> {command line option}.

	3. <networking> {packet switch}, {circuit switch}.

	(1999-01-14)

<operating system> A character string which tells a program to
	perform a specific action.  Most commands take {arguments}
	which either modify the action performed or supply it with
	input.  Commands may be typed by the user or read from a file
	by a {command interpreter}.  It is also common to refer to
	menu items as commands.

	(1997-06-21)

1. <storage> Integrated Drive Electronics, see {Advanced
	Technology Attachment}.

	2. <programming, tool> {integrated development environment}.

	3. <company> {Interactive Development Environments}.

	(2002-04-14)

<hardware> To press and release a {button} on a {mouse} or
	other {pointing device}.  This generates an {event}, also
	specifying the screen position, which is processed by the
	{window manager} or {application program}.  On a mouse with
	more than one button, the unqualified term usually implies
	pressing the left-most button (with the right index finger),
	other buttons would be qualified, e.g. "{right-click}".
	{Keyboard} modifiers may also be used, e.g. "shift-click",
	meaning to hold down the shift key on the keyboard while
	clicking the mouse button.

	If the mouse moves while the button is pressed then this is a
	{drag}.

	(1995-03-14)

A {Unix} {C} language processor which carries out more
	thorough checks on the code than is usual with C {compilers}.

	Lint is named after the bits of fluff it supposedly picks from
	programs.  Judging by references on {Usenet} this term has
	become a shorthand for {desk check} at some non-Unix shops,
	even in languages other than {C}.  Also used as {delint}.

	[{Jargon File}]

	(1994-11-14)

<architecture> {Data} transferred from a computer system to
	the outside world via some kind of {output device}.

	Opposite: {input}.

	(1997-04-28)

<theory, programming> (Or "data type") A set of values from
	which a {variable}, {constant}, {function}, or other
	{expression} may take its value.  A type is a classification
	of data that tells the {compiler} or {interpreter} how the
	programmer intends to use it.  For example, the process and
	result of adding two variables differs greatly according to
	whether they are integers, floating point numbers, or strings.

	Types supported by most programming languages include
	{integers} (usually limited to some range so they will fit in
	one {word} of storage), {Booleans}, {floating point numbers},
	and characters.  {Strings} are also common, and are
	represented as {lists} of characters in some languages.

	If s and t are types, then so is s -> t, the type of
	{functions} from s to t; that is, give them a term of type s,
	functions of type s -> t will return a term of type t.

	Some types are {primitive} - built-in to the language, with no
	visible internal structure - e.g. Boolean; others are
	composite - constructed from one or more other types (of
	either kind) - e.g. {lists}, {arrays}, {structures}, {unions}.
	{Object-oriented programming} extends this with {classes}
	which encapsulate both the structure of a type and the
	operations that can be performed on it.

	Some languages provide {strong typing}, others allow {implicit
	type conversion} and/or {explicit type conversion}.

	(2003-12-22)

(From the technical term "logical device", wherein a physical
	device is referred to by an arbitrary "logical" name) Having
	the role of.  If a person (say, Les Earnest at SAIL) who had
	long held a certain post left and were replaced, the
	replacement would for a while be known as the "logical" Les
	Earnest.  (This does not imply any judgment on the
	replacement).

	Compare {virtual}.

	At Stanford, "logical" compass directions denote a coordinate
	system in which "logical north" is toward San Francisco,
	"logical west" is toward the ocean, etc., even though logical
	north varies between physical (true) north near San Francisco
	and physical west near San Jose.  (The best rule of thumb here
	is that, by definition, El Camino Real always runs logical
	north-and-south.)  In giving directions, one might say: "To
	get to Rincon Tarasco restaurant, get onto {El Camino Bignum}
	going logical north."  Using the word "logical" helps to
	prevent the recipient from worrying about that the fact that
	the sun is setting almost directly in front of him.  The
	concept is reinforced by North American highways which are
	almost, but not quite, consistently labelled with logical
	rather than physical directions.

	A similar situation exists at MIT: Route 128 (famous for the
	electronics industry that has grown up along it) is a
	3-quarters circle surrounding Boston at a radius of 10 miles,
	terminating near the coastline at each end.  It would be most
	precise to describe the two directions along this highway as
	"clockwise" and "counterclockwise", but the road signs all say
	"north" and "south", respectively.  A hacker might describe
	these directions as "logical north" and "logical south", to
	indicate that they are conventional directions not
	corresponding to the usual denotation for those words.  (If
	you went logical south along the entire length of route 128,
	you would start out going northwest, curve around to the
	south, and finish headed due east, passing along one infamous
	stretch of pavement that is simultaneously route 128 south and
	Interstate 93 north, and is signed as such!)

	[{Jargon File}]

	(1995-01-24)

A group of {application programs} from {Lotus Development
	Corporation} which allows organisations to share documents and
	exchange {electronic mail} messages.  Notes supports
	{replication}.

	(1994-10-27)

<programming> An {object} or {routine} for accessing items
	from a {list}, {array} or {stream} one at a time.

	By extension, the term can be used for an object or routine
	for accesing items from any data structure that can be viewed
	as a list.  For example, a {traverser} is an {iterator} for
	{tree}-shaped data structures.

	(2001-10-04)

<programming> (API, or "application programming interface")
	The interface (calling conventions) by which an {application
	program} accesses {operating system} and other services.  An
	API is defined at {source code} level and provides a level of
	{abstraction} between the application and the {kernel} (or
	other privileged utilities) to ensure the {portability} of the
	code.

	An API can also provide an interface between a {high level
	language} and lower level utilities and services which were
	written without consideration for the {calling conventions}
	supported by compiled languages.  In this case, the API's main
	task may be the translation of parameter lists from one format
	to another and the interpretation of {call-by-value} and
	{call-by-reference} arguments in one or both directions.

	(1995-02-15)

1. The art of debugging a blank sheet of paper (or, in these
	days of on-line editing, the art of debugging an empty file).

	2. A pastime similar to banging one's head against a wall, but
	with fewer opportunities for reward.

	3. The most fun you can have with your clothes on (although
	clothes are not mandatory).

	[{Jargon File}]

	(2003-02-12)

<graphics> (AWT) {Java}'s {platform}-independent {windowing},
	graphics, and user-interface {toolkit}.  The AWT is part of
	the {Java Foundation Classes} (JFC) - the standard {API} for
	providing a {graphical user interface} (GUI) for a Java
	program.

	Compare: {SWING}.

	["Java in a Nutshell", O'Reilly].

	{Home (http://java.sun.com/products/jdk/awt/)}.

	(2000-07-26)