High Level Data Structure - the Grid

Grids are arrays that can have any shape: grid elements need not be connected to each other (e.g., a grid may be pyramid-like or two disjoint rectangular pieces). Programs using grids are smaller, semantically clearer, more general and easier to modify than programs that simulate non array-like shapes. We present a notation for specifying grids in PASCAL. Grids have been implemented as an extension to FORTRAN.