FPCA

Most programs written today are “object-level” programs. That is, programs describe how to combine various “objects” (i.e., numbers, symbols, arrays, etc.) to form other objects until the final “result objects” have been formed. New objects are ...

This paper begins by presenting arguments for including data abstraction and compile time type checking in functional programming languages, and discussing in general terms the mechanisms required to provide support for these features. It then goes on ...

An important feature of the applicative style is the use of operators that package common patterns of computation. For example, the list operator map applies a function to every element of a list. Practical use of this style has been hampered by the ...

Functional languages provide a framework in which combining existing programs to produce new ones is particularly simple and elegant. However, the penalty usually paid for such simplicity and elegance is poor execution efficiency, especially if the ...

The perceived inefficiency in execution functional programming languages has been an obstacle to their widespread acceptance. Consequently, algorithms are often coded for efficient execution at the expense of clarity. This compromises the functional ...

We describe the data definition facilities of a new applicative language called CDS, which is based on Kahn-Plotkin's theory of concrete data structures and on Berry-Curien's theory of sequential algorithms. CDS is together an higher-order applicative ...

Operators in functional languages such as APL and FFP are a useful programming concept. However, this concept cannot be fully exploited in these languages because of certain constraints. It is proposed that an operator should be associated with a ...

The functional or applicative languages have long been regarded as suitable vehicles for overcoming many of the problems involved in the production and maintenance of correct and reliable software. However, their inherent inefficiences when run on ...

Recent proposals for nondeterministic facilities in high-level dataflow programming systems have stopped short of giving details of low-level implementation. The underlying machine is assumed to provide basic nondeterministic operations which lead to ...

In what does the alleged superiority of applicative languages consist? In the last analysis the answer must be in terms of the reduction in the time required to produce a correct program to solve a given problem. On reflection I decided that the best ...

In functional programming languages with reduction semantics, operators “use up” their operands to produce their results. This makes it difficult to execute efficiently certain computations, such as one in which several operators are applied—in ...

The performance of the cellular computer proposed by Megó has been investigated by programming a number of associative search algorithms and analyzing the time and space required for their execution. The present work describes the results of three ...

A cellular binary tree machine proposed by Magó accommodates the parallelism inherent in the functional programming languages of Backus by simultaneously executing innermost applications. Data communication time on this machine is linear in the number ...

The computer architecture described here was inspired by Magó's recently proposed cellular computer [1979] based on the Formal Functional Programming (FFP) languages introduced by Backus [1978]. Magó's machine is a binary tree of many simple processor/...

The use of feedback loops in functional programming languages is explored, particularly in the context of graph-based semantic models. In this setting, program cycles (termed “applicative loops”) offer benefits that are both conceptual (e.g. providing ...

The “referential transparency” of applicative language expressions demands that all occurrences of an expression in a given context yield the same value. In principle, that value therefore needs to be computed only once. However, in recursive ...

Per Martin-Löf's Constructive Set Theory is a mathematical language with computation rules. It is primarily designed to be a language for mathematical reasoning. The language has a very simple semantics and its rules have a simple structure. Since it is ...

Our aim is to investigate means for expressing programs and their design, in such a way that the logical consistency of each expression be ensured constructively, and that the structure of the expressions be general and elegant. It is more and more ...

Logic programs offer many opportunities for parallelism. We present an abstract model that exploits the parallelism due to nondeterministic choices in a logic program. A working interpreter based on this model is described, along with variants of the ...

A parallel program often defines a relation not a function. The program constrains the output to lie in some relation R to the input, but the particular output produced during a computation can depend on the time behaviour of component processes. This ...

Programs described via recursive equations provide many opportunities for concurrent computation. For example, a machine may choose to concurrently initiate the evaluation of all subexpressions within a given expression. This “eager beaver” evaluation ...

A wide variety of computational models, including the lambda calculus, may be represented by a set of reduction rules which guide the (run-time) construction of a process tree. Even a single source of parallelism in an otherwise lazy evaluator may give ...

Functional programming systems, although they have nice theoretical properties and elegant implementations, have failed to make any significant impact in the practical world of applications programming. We shall describe a simple FP system for databases ...

A high level specification language called Business Data-Flow Language (BDFL) based on the data-flow model of computation is described in this paper. A translator to convert BDFL specifications into COBOL programs has been implemented. A novel feature ...

In this paper we discuss relational programming, i.e. a style of programming in which entire relations are manipulated rather than individual data. This analogous to functional programming [1], wherein entire functions are the values manipulated by the ...

An essential part of an FP programmer's task is keeping track of the intermediate data structures of an FP program. This paper describes a way of documenting FP program with descriptions of its data structures and automatically proving that this ...