C--

C-- (pronounced C minus minus) is a C-like programming language. Its creators, functional programming researchers Simon Peyton Jones and Norman Ramsey, designed it to be generated mainly by compilers for very high-level languages rather than written by human programmers. Unlike many other intermediate languages, its representation is plain ASCII text, not bytecode or another binary format. There are two main branches: C--, the original branch, with the final version 2.0 released in May 2005 Cmm, the fork actively used as the intermediate representation (IR) in the Glasgow Haskell Compiler (GHC) C-- is a "portable assembly language", designed to ease the implementation of compilers that produce high-quality machine code. This is done by delegating low-level code-generation and program optimization to a C-- compiler. The language's syntax borrows heavily from C while omitting or changing standard C features such as variadic functions, pointer syntax, and aspects of C's type system, because they hamper essential features of C-- and ease of code-generation. The name of the language is an in-joke, indicating that C-- is a reduced form of C, in the same way that "C++" was chosen to connote an improved version of C. (In C, -- and ++ mean "decrement" and "increment," respectively.) Work on C-- began in the late 1990s. Since writing a custom code generator is a challenge in itself, and the compiler backends available to researchers at that time were complex and poorly documented, several projects had written compilers which generated C code (for instance, the original Modula-3 compiler). However, C is a poor choice for functional languages: it does not guarantee tail-call optimization, or support accurate garbage collection or efficient exception handling. C-- is a tightly-defined simpler alternative to C which supports all of these. Its most innovative feature is a run-time interface which allows writing of portable garbage collectors, exception handling systems and other run-time features which work with any C-- compiler.