Technical Report 1304, Christian-Albrechts-Universität zu Kiel, 2013
Functional logic languages combine lazy (demand-driven) evaluation strategies from functional programming with non-deterministic computations from logic programming. To provide a strategy-independent semantics, most languages are based on the call-time choice semantics where parameters are passed as values. From an implementation point of view, the call-time choice semantics fits well with sharing performed by lazy languages. On the other hand, there are also situations where it is intended to pass non-deterministic arguments as sets of values in order to exploit the power of non-deterministic programming. This alternative parameter passing model is known under the name "plural" arguments. In this paper, we show how both mechanisms can be integrated in a single language. In particular, we present a novel technique to implement plural arguments in a call-time choice language so that existing implementations of contemporary functional logic languages can be easily re-used to implement plural parameter passing.
The following material is provided here:
Here are the sources of the benchmarks used in the paper:
| PAKCS | Maude | |
|---|---|---|
| naive reverse | benchmark.curry |
benchmark.plural |
| palindrome | pali.curry |
pali.plural |
| number and expression parser | expr.curry |
expr.plural |