A new datatype, called a block, has been implemented for SNOBOL4. A block is a three-dimensional aggregate of characters in the form of a right parallelepiped, best thought of as a three-dimensional extension to a string. (The third dimension is used for overstriking.) Blocks may be printed, concatenated in any of three dimensions, and merged on the basis of program-defined connection points. Some blocks adapt in size and shape to their environment. Blocks and their operations are mainly used for composing printable output. A variety of graphical problems (including flowcharting, bargraphs, logic diagrams, mathematical-equation formation, and text justification and preparation) have been programmed on a printer in what appears to be an easy and natural way. In addition to these somewhat specialized applications, blocks appear to be a good general purpose device-independent output formation mechanism especially suitable for nonnumerical work. The concept of a block is largely language independent. That is, blocks require little in the way of specialized syntax and could readily be absorbed into the external structure of most programming languages.
The Latest from CACM
Shape the Future of Computing
ACM encourages its members to take a direct hand in shaping the future of the association. There are more ways than ever to get involved.
Get InvolvedCommunications of the ACM (CACM) is now a fully Open Access publication.
By opening CACM to the world, we hope to increase engagement among the broader computer science community and encourage non-members to discover the rich resources ACM has to offer.
Learn More
Join the Discussion (0)
Become a Member or Sign In to Post a Comment