## A Semantics for Shape (1995)

Venue: | Science of Computer Programming |

Citations: | 60 - 18 self |

### BibTeX

@ARTICLE{Jay95asemantics,

author = {C. Barry Jay},

title = {A Semantics for Shape},

journal = {Science of Computer Programming},

year = {1995},

volume = {25},

pages = {25--251}

}

### Years of Citing Articles

### OpenURL

### Abstract

Shapely types separate data, represented by lists, from shape, or structure. This separation supports shape polymorphism, where operations are defined for arbitrary shapes, and shapely operations, for which the shape of the result is determined by that of the input, permitting static shape checking. The shapely types are closed under the formation of fixpoints, and hence include the usual algebraic types of lists, trees, etc. They also include other standard data structures such as arrays, graphs and records. 1 Introduction The values of a shapely type are uniquely determined by their shape and their data. The shape can be thought of as a structure with holes or positions, into which data elements (stored in a list) can be inserted. The use of shape in computing is widespread, but till now it has not, apparently, been the subject of independent study. The body of the paper presents a semantics for shape, based on elementary ideas from category theory. First, let us consider some examp...