Basic Language for Implementation of System Software definition language
(BLISS, or allegedly, "System Software Implementation Language, Backwards") A language designed by W.A. Wulf at CMU
BLISS is an expression language. It is block-structured
, and typeless, with exception handling facilities, coroutines, a macro
system, and a highly optimising compiler
. It was one of the first non-assembly languages
for operating system
implementation. It gained fame for its lack of a goto
and also lacks implicit dereferencing: all symbols stand for addresses, not values.
Another characteristic (and possible explanation for the backward acronym) was that BLISS fairly uniformly used backward keywords
for closing blocks, a famous example being ELUDOM to close a MODULE. An exception was BEGIN...END though you could use (...) instead.
DEC introduced the NOVALUE keyword in their dialects to allow statements to not return a value.
Versions: CMU BLISS-10
for the PDP-10; CMU BLISS-11
, BLISS-16, DEC BLISS-16C
, DEC BLISS-32
["BLISS: A Language for Systems Programming", CACM 14(12):780-790, Dec 1971].
[Did the B stand for "Better"?]