An Integrated Information System Powered by Prolog

Porto, António

doi:10.1007/3-540-36388-2_8

Cited by 4 publications

(2 citation statements)

References 2 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The ideas in the paper have been turned into a practical alternative to Prolog, easy to program and debug, and more readily amenable to partial evaluation, important for compile-time optimisation of clean high-level declarative code. The language-Cube-has been implemented on top of a Prolog system and heavily used to good effect in building a sophisticated large real-world application (Porto 2003). It incorporates several other features such as structural abstraction and application (Porto 2002) for higher order and functional notation.…”

Section: Conclusion and Further Workmentioning

confidence: 99%

See 1 more Smart Citation

A structured alternative to Prolog with simple compositional semantics

Porto¹

2011

Theory and Practice of Logic Programming

Self Cite

View full text Add to dashboard Cite

Prolog's very useful expressive power is not captured by traditional logic programming semantics, due mainly to the cut and goal and clause order. Several alternative semantics have been put forward, exposing operational details of the computation state. We propose instead to redesign Prolog around structured alternatives to the cut and clauses, keeping the expressive power and computation model but with a compositional denotational semantics over much simpler states-just variable bindings. This considerably eases reasoning about programs, by programmers and tools such as a partial evaluator, with safe unfolding of calls through predicate definitions. An if-then-else across clauses replaces most uses of the cut, but the cut's full power is achieved by an until construct. Disjunction, conjunction and until, along with unification, are the primitive goal types with a compositional semantics yielding sequences of variable-binding solutions. This extends to programs via the usual technique of a least fixpoint construction. A simple interpreter for Prolog in the alternative language, and a definition of until in Prolog, establish the identical expressive power of the two languages. Many useful control constructs are derivable from the primitives, and the semantic framework illuminates the discussion of alternative ones. The formalisation rests on a term language with variable abstraction as in the {\lambda}-calculus. A clause is an abstraction on the call arguments, a continuation, and the local variables. It can be inclusive or exclusive, expressing a local case bound to a continuation by either a disjunction or an if-then-else. Clauses are open definitions, composed (and closed) with simple functional application ({\beta}-reduction). This paves the way for a simple account of flexible module composition mechanisms. Cube, a concrete language with the exposed principles, has been implemented.Comment: 27th Int'l. Conference on Logic Programming (ICLP'11) Special Issue, 201

show abstract

Section: Conclusion and Further Workmentioning

confidence: 99%

“…Our design principles led us to implement a concrete language, called Cube, on top of a Prolog engine and successfully use it, for a number of years and by many programmers, to build complex real-world applications such as the online academic management system at our previous Faculty (Porto 2003).…”

Section: Introductionmentioning

confidence: 99%