Go! (programming language): Difference between revisions

Revision as of 01:13, 12 January 2024

Revision as of 01:46, 12 January 2024

Line 33:

== Example ==

The following example illustrates the "ontology-oriented" type and declarations style of Go!:<ref name=applied />

<syntaxhighlight lang="haskell">

<!-- Don't use <source> tag, because there is wikitext in the source code. -->

Sex [[#algebraic|'''::=''']] male | female.

person [[#interface|'''<~''']] {dayOfBirth:[] '''=>''' ''day''.

age:[] '''=>''' ''integer''.

sex:[] '''=>''' Sex.

name:[] '''=>''' ''string''.

home:[] '''=>''' ''string''.

lives:[''string'']{}}.

person:[''string'', ''day'', Sex, ''string''] [[#theory|'''$=''']] person.

person(Nm, Born, Sx, Hm)..{

dayOfBirth() '''=>''' Born.

age() '''=>''' yearsBetween(now(), Born).

sex() '''=>''' Sx.

name() '''=>''' Nm.

home() '''=>''' Hm.

lives(Pl) [[Prolog#Rules and facts|''':-''']] Pl '''=''' home().

yearsBetween:[''integer'', ''day''] '''=>''' integer.

yearsBetween(...) '''=>''' ..

}.

newPerson:[''string'', ''day'', Sex, ''string''] '''=>''' person.

newPerson(Nm, Born, Sx, Hm) '''=>''' $person(Nm, Born, Sx, Hm).

person [[#interface|'''<~''']] {dayOfBirth:[] '''=>''' ''day''.

{{anchor|algebraic}}The <code>::=</code> rule defines a new [[algebraic data type]], a [[data type]] with only data constructors.

age:[] '''=>''' ''integer''.

sex:[] '''=>''' Sex.

name:[] '''=>''' ''string''.

home:[] '''=>''' ''string''.

lives:[''string'']{}}.

person:[''string'', ''day'', Sex, ''string''] [[#theory|'''$=''']] person.

{{anchor|interface}}The <code><~</code> rule defines an interface type - it indicates what properties are characteristic of a <code>person</code> and also gives type constraints on these properties. It documents that <code>age</code> is a functional property with an integer value, that <code>lives</code> is a unary relation over strings, and that <code>dayOfBirth</code> is a functional property with a value that is an object of type <code>day</code>.

person(Nm, Born, Sx, Hm)..{

{{anchor|theory}}The <code>$=</code> type rule indicates that there is also a theory label, with the functor <code>person</code>, for a theory that defines the characteristic properties of the <code>person</code> type - implements the <code>person</code> interface - in terms of four given parameters of types <code>string</code>, <code>day</code> , <code>Sex</code>, and <code>string</code>.

dayOfBirth() '''=>''' Born.

age() '''=>''' yearsBetween(now(), Born).

sex() '''=>''' Sx.

name() '''=>''' Nm.

home() '''=>''' Hm.

lives(Pl) [[Prolog#Rules and facts|''':-''']] Pl '''=''' home().

yearsBetween:[''integer'', ''day''] '''=>''' integer.

yearsBetween(...) '''=>''' ..

}.

newPerson:[''string'', ''day'', Sex, ''string''] '''=>''' person.

newPerson(Nm, Born, Sx, Hm) '''=>''' $person(Nm, Born, Sx, Hm).

</syntaxhighlight>

{{anchor|algebraic}}*The <code>::=</code> rule defines a new [[algebraic data type]], a [[data type]] with only data constructors.

{{anchor|interface}}*The <code><~</code> rule defines an interface type - it indicates what properties are characteristic of a <code>person</code> and also gives type constraints on these properties. It documents that <code>age</code> is a functional property with an integer value, that <code>lives</code> is a unary relation over strings, and that <code>dayOfBirth</code> is a functional property with a value that is an object of type <code>day</code>.

{{anchor|theory}}*The <code>$=</code> type rule indicates that there is also a theory label, with the functor <code>person</code>, for a theory that defines the characteristic properties of the <code>person</code> type - implements the <code>person</code> interface - in terms of four given parameters of types <code>string</code>, <code>day</code> , <code>Sex</code>, and <code>string</code>.

==Conflict with Google==