Article URL: https://en.wikipedia.org/wiki/BLISS Comments URL: https://news.ycombinator.com/item?id=48873910 Points: 26 # Comments: 4

BLISS is a system programming language developed at Carnegie Mellon University (CMU) by W. A. Wulf, D. B. Russell, and A. N. Habermann around 1970. It was perhaps the best known system language until C debuted a few years later. Since then, C became popular and common, and BLISS faded into obscurity. BLISS is a typeless block-structured programming language based on expressions rather than statements, and includes constructs for exception handling, coroutines, and macros. It does not include a goto statement. The name is variously said to be short for Basic Language for Implementation of System Software or System Software Implementation Language, Backwards. However, in his 2015 oral history for the Babbage Institute's Computer Security History Project, Wulf claimed that the acronym was originally based on the name "Bill's Language for Implementing System Software."[1] The original Carnegie Mellon compiler was notable for its extensive use of optimizations, and formed the basis of the classic book The Design of an Optimizing Compiler. Digital Equipment Corporation (DEC) developed and maintained BLISS compilers for the PDP-10,[2] PDP-11,[2] VAX,[2] DEC PRISM,[3] MIPS,[2] DEC Alpha,[2] and Intel IA-32,[2] The language did not become popular among customers and few had the compiler,[4] but DEC used it heavily in-house into the 1980s; most of the utility programs for the OpenVMS operating system were written in BLISS-32. The DEC BLISS compiler has been ported to the IA-64 and x86-64 architectures as part of the ports of OpenVMS to these platforms.[2][5] The x86-64 BLISS compiler uses LLVM as its backend code generator, replacing the proprietary GEM backend used for Alpha and IA-64. BLISS has many of the features of other modern high-level languages. It has block structure, an automatic stack, and mechanisms for defining and calling recursive routines ... provides a variety of predefined data structures and ... facilities for testing and iteration ... On the other hand, BLISS omits certain features of other high-level languages. It does not have built-in facilities for input/output, because a system-software project usually develops its own input/output or builds on basic monitor I/O or screen management services ... it permits access to machine-specific features, because system software often requires this. BLISS has characteristics that are unusual among high-level languages. A name ... is uniformly interpreted as the address of that segment rather than the value of the segment ... Also, BLISS is an "expression language" rather than a "statement language".[6]