Accumulators: New logic variable abstractions for functional languages

Time Equations for Lazy Functional (Logic) Languages

There are very few approaches to measure the execution costs of lazy functional (logic) programs. The use of a lazy execution mechanism implies that the complexity of an evaluation depends on its context, i.e., the evaluation of the same expression may have different costs depending on the degree of evaluation required by the different contexts where it appears. In this paper, we present a nove...

Operational Semantics for Functional Logic Languages

In this work we provide a semantic description of functional logic languages covering notions like laziness, sharing, and non-determinism. Such a semantic description is essential, for instance, to have appropriate language definitions in order to reason about programs and check the correctness of implementations. First, we define a “big-step” semantics in natural style to relate expressions an...

Parallel Evaluation Strategies for Functional Logic Languages

We introduce novel, sound, complete, and locally optimal evaluation strategies for functional logic programming languages. Our strategies combine, in a non-trivial way, two landmark techniques in this area: the computation of unifiers performed by needed narrowing in inductively sequential rewrite systems and the simultaneous reduction of a necessary set of redexes performed by rewriting in wea...

Markup Languages for Functional-Logic Programming

Run-time debugging for functional logic languages

This thesis describes the design, implementation and use of a run-time debugging tool for understanding the lazy semantics and locating failures in the functional logic language Curry. We provide a means for programmers to step in the evaluation order of program expressions at a source code level. Every expression evaluated is detected by a program coverage in a layout of the source code. Its r...