Go! is an
agent-based programming language in the tradition of
logic-based programming languages like
Prolog
Prolog is a logic programming language associated with artificial intelligence and computational linguistics.
Prolog has its roots in first-order logic, a formal logic, and unlike many other programming languages, Prolog is intended primarily ...
.
It was introduced in a 2003 paper by Francis McCabe and
Keith Clark.
Design
The authors of Go! describe it as "a
multi-paradigm programming language that is oriented to the needs of programming secure, production quality and agent-based applications. It is
multi-threaded
In computer science, a thread of execution is the smallest sequence of programmed instructions that can be managed independently by a scheduler, which is typically a part of the operating system. The implementation of threads and processes dif ...
, strongly typed and
higher order (in the functional programming sense). It has relation, function and action procedure definitions. Threads execute action procedures, calling functions and querying relations as needed. Threads in different agents communicate and coordinate using asynchronous messages. Threads within the same agent can also use shared dynamic relations acting as
Linda
Linda may refer to:
As a name
* Linda (given name), a female given name (including a list of people and fictional characters so named)
* Linda (singer) (born 1977), stage name of Svetlana Geiman, a Russian singer
* Anita Linda (born Alice Lake i ...
-style
tuple stores."
The authors also propose that the language is suitable for representing
ontologies
In computer science and information science, an ontology encompasses a representation, formal naming, and definition of the categories, properties, and relations between the concepts, data, and entities that substantiate one, many, or all domains ...
due to its integration of
logic
Logic is the study of correct reasoning. It includes both formal and informal logic. Formal logic is the science of deductively valid inferences or of logical truths. It is a formal science investigating how conclusions follow from premise ...
,
functional and
imperative styles of programming.
Example
The following example illustrates the "ontology-oriented" type and declarations style of Go!:
Sex
::= male , female.
person
<~ .
person:
'string'', ''day'', Sex, ''string'' $= person.
person(Nm, Born, Sx, Hm)...
newPerson:
'string'', ''day'', Sex, ''string''=> person.
newPerson(Nm, Born, Sx, Hm) => $person(Nm, Born, Sx, Hm).
The
::= rule defines a new
algebraic data type
In computer programming, especially functional programming and type theory, an algebraic data type (ADT) is a kind of composite type, i.e., a type formed by combining other types.
Two common classes of algebraic types are product types (i.e., ...
, a
data type with only data constructors.
The
<~ rule defines an interface type - it indicates what properties are characteristic of a
person and also gives type constraints on these properties. It documents that
age is a functional property with an integer value, that
lives is a unary relation over strings, and that
dayOfBirth is a functional property with a value that is an object of type
day.
The
$= type rule indicates that there is also a theory label, with the functor
person, for a theory that defines the characteristic properties of the
person type - implements the
person interface - in terms of four given parameters of types
string,
day ,
Sex, and
string.
Conflict with Google
In November 2009,
Google
Google LLC () is an American Multinational corporation, multinational technology company focusing on Search Engine, search engine technology, online advertising, cloud computing, software, computer software, quantum computing, e-commerce, ar ...
released a similarly named
Go programming language (with no
exclamation point
The exclamation mark, , or exclamation point (American English), is a punctuation mark usually used after an interjection or exclamation to indicate strong feelings or to show emphasis. The exclamation mark often marks the end of a sentence, f ...
). McCabe asked Google to change the name of their language as he was concerned they were "steam-rolling over us".
The issue received attention among technology news websites, with some of them characterizing Go! as "obscure". The issue thread opened on the subject was closed by a Google developer on 12 October 2010 with the custom status "Unfortunate" and with the following comment: "there are many computing products and services named Go. In the 11 months since our release, there has been minimal confusion of the two languages."
References
Further reading
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{{Refend
External links
Github page
Concurrent programming languages
Free compilers and interpreters
Programming languages created in 2003