SAIL (programming language)

The SAIL (Stanford Artificial Intelligence Language) programming language was developed in the 1970s by Dan Swinehart and Bob Sproull at the Stanford AI Laboratory at Stanford University. Originally SAIL was an extensive Algol 60 -like language for the PDP -10 and DECsystem -20 computer of the Digital Equipment Corporation.

Main characteristic of SAIL was a symbolic data storage, based on an associative memory. This system was a further development of the programming language LEAP by Jerry Feldman and Paul Rovner. Data could be stored therein as unordered sets or as associations ( triplets ). Other features were the ability to process control with events and interrupts, managing contexts, backtracking, and a memory management (garbage collection ). SAIL contained block- structured macros, one way to write coroutines and a whole lot of new data types, with which one could make search trees and associative lists.

A number of interesting software systems has been programmed in SAIL, such as early versions of FTP and TeX, a document formatting system called PUB and the first interactive spreadsheet program BRIGHT.

In 1978 there were half a dozen different operating systems for the PDP-10: ITS ( MIT), WAITS (Stanford ), TOPS -10 ( DEC), CMU TOPS -10 ( Carnegie Mellon ), TENEX (BBN ) and TOPS -20 ( from DEC based on TENEX ). SAIL has been ported from WAITS by ITS, so the researchers were able to use developed at Stanford University software at MIT. The port normally required a complete rewriting of the E / A code of each affected application.

A machine-independent version of SAIL named MAIN SAIL was developed in the late 1970s and used in the development of many ECAD programs in the 1980s. MAIN SAIL was easily ported to new processors and operating systems, and is still used occasionally by the turn of the millennium.