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This paper introduces a set of combinators for building lexical analysers in a lazy functional language. During lexical analysis, the combinators generate a deterministic, table-driven analyser on the fly. Consequently, the presented method combines the efficiency of off-line scanner generators with the flexibility of the combinator approach. The method makes essential use of the lazy semantics of the implementation language Haskell. Finally, the paper discusses benchmarks of a scanner for the programming language C. 1 Introduction There are two conceptually different approaches to obtaining a functional implementation of a scanner or parser from a formal lexical or syntactic specification: (1) the specification is written in a special purpose language and translated into a functional program by a scanner or parser generator or (2) the specification is composed from a set of combinators provided by a scanner or parser combinator library. Both approaches have their advantages a...

The constraint functional language GOFFIN extends the purely functional Haskell with combinators from concurrent....

. Data fields provide a flexible and highly general model for indexed collections of data. Data Field Haskell is a Haskell dialect that provides an instance of data fields. It can be used for very generic collection-oriented programming, with a special emphasis on multidimensional structures. We give a brief description of the data field model and its underlying theory. We then describe Data Field Haskell, and an implementation. 1 Introduction Indexed data structures are important in many computing applications. The canonical indexed data structure is the array, but other indexed structures like hash tables and explicitly parallel entities are also common. In many applications the indexing capability provides an important part of the model: when solving partial differential equations, for instance, the index is often closely related to a physical coordinate, and explicitly parallel algorithms often use processor ID's as indices. Since the time of APL [5] it has been recognised ...

. Data fields are partial functions provided with explicit domain information. They provide a very general, formal model for collections of data. Algorithms computing data collections can be described in this formalism at various levels of abstraction: in particular, explicit data distributions are easy to model. Parallel versions of algorithms can then be formally verified against algorithm specifications in the model. Functions computing data fields can be directly programmed in the language Data Field Haskell. In this paper we give a brief introduction to the data field model. We then describe Data Field Haskell and make a small case study of how an algorithm and a parallel version of it both can be specified in the language. We then verify the correctness of the parallel version in the data field model. 1 Introduction Many computing applications require indexed data structures. In many applications the indexing capability provides an important part of the model. On the ...