ALGOL 68metasyntax notation (not BNF) and its unconventional terminology. One of the singular features of ALGOL 68 was its orthogonal design, making for freedom from arbitrary rules (such as restrictions in other languages that arrays could only be used as parameters but not as results). It also allowed user defined data types, then an unheard-of feature. It featured structural equivalence; automatic type conversion ("coercion") including dereferencing; flexible arrays; generalised loops (for-from-by-to-while-do-od), if-then-else-elif-fi, an integer case statement with an 'out' clause (case-in-out-esac); skip and goto statements; blocks; procedures; user-defined operators; procedure parameters; concurrent execution (par-begin-end); semaphores; generators "heap" and "loc" for dynamic allocation. It had no abstract data types or separate compilation. http://www.bookrags.com/research/algol-68-wcs/.
Last updated: 2007-04-24