a multi-theory logic language for the world wide web

A Multi-theory Logic Language for the World Wide Web

Giulio Piancastelli and Andrea Omicini24th International Conference on Logic Programming (ICLP 2008)

Udine, December 9-13, 2008

Purpose

Bring principles, abstractions, and insights from the Web architecture to research on the use of logic programming for Web application prototyping

Resource

Any conceptual target of a hypertext reference

Composed of:• identifier (URI)• data• behavior

http://example.com/sales/2004/Q4

http://example.com/sales/2004/Q4

f(a).r(P, Q) :- s(P), t(Q).

R

T(R)

http://example.com/sales/2004/Q4

Rhttp://example.com/sales/2004/

R1

T(R1)

T(R)

http://example.com/sales/

R2

http://example.com/sales/2004/Q4

Rhttp://example.com/sales/2004/

R1

T(R1)

T(R)

T(R2)

http://example.com/sales/2004/Q4

Rhttp://example.com/sales/2004/

R1

T(R1)

T(R)http://example.com/sales/

R2

T(R2)

R

http://example.com/sales/Q42004/

http://example.com/sales/2004/Q4

Rhttp://example.com/sales/2004/

R1

T(R1)

T(R)http://example.com/sales/

R2

T(R2)

Implicit Resources

Resources representing recurring concepts in Web development that are always attached to the bottom of any context• the session with the application• the user

• the application itself• the deployment environment

HTTP

GET /sales/2004/Q4 HTTP/1.1Host: example.com

HTTP

GET /sales/2004/Q4 HTTP/1.1Host: example.com

Method Information: how thereceiver has to process therequest

'/sales/2004/Q4' : get(Request, Response, View).

HTTP

GET /sales/2004/Q4 HTTP/1.1Host: example.com

Scope Information: the datawhere the receiver shouldoperate the method

'/sales/2004/Q4' : get(Request, Response, View).

/r2/r1/r

get(_, _, V) :- a, b, c(V).a :- p, q, r.

R

T(R)

/r2/r1

R1

/r2/r1/r

get(_, _, V) :- a, b, c(V).a :- p, q, r.

R

T(R)

/r2

R2

/

root

/r2/r1

R1

/r2/r1/r

get(_, _, V) :- a, b, c(V).a :- p, q, r.

R

T(R)

p :- x, y, z.x.

T(root)

/r2

R2

/

root

/r2/r1

R1

/r2/r1/r

get(_, _, V) :- a, b, c(V).a :- p, q, r.

R

T(R)

p :- x, y, z.x.

T(root)

Dynamic Resource Behavior (1)

Two or more URIs can be associated to the same resource: resources may live in different contexts at the same time and feature different behavior according to the context where the computation takes place.

Dynamic Resource Behavior (2)

Behavioral rules are expressed as first-class abstractions in logic programming languages, where programs can be treated as data: the HTTP protocol allows changing resource data by using the PUT method, so that runtime behavioral changes of a resource in a context are possible.

A Multi-theory Logic Language for the World Wide Web

Giulio Piancastelli and Andrea Omicini24th International Conference on Logic Programming (ICLP 2008)

Udine, December 9-13, 2008