TRAC programming language
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TRAC (for Text Reckoning And Compiling) is a computer language developed in the early 1960s by Calvin Mooers (1919-1994). It was one of three "first languages" recommended by Ted Nelson in Computer Lib.
TRAC was a purely text-based language—a kind of macro language. Unlike traditional ad hoc macro languages of the time, such as those found in assemblers, TRAC was well-thought-out, consistent, and in many senses complete. It also differs from them in that TRAC numbers are strings of digits, with integer arithmetic (without specific limits on maximum values) being provided through built-in ("primitive") functions. Arguably, one aspect of its completeness is that the concept of error is limited to events like lack of file space and requesting expansion of a string longer than the interpreter's working storage; what would in many languages be described as illegal operations are dealt with in TRAC by defining a result (often a null string) for every possible combination of a function's argument strings.
The emphasis on strings as strings is so strong that TRAC provides mechansisms for handling the language's own syntactic characters either in their syntactic roles or like any other character, and self-modifying code has more the feel of a natural consequence of typical TRAC programming techniques than of being a special feature.
TRAC is, like APL or LISP, an expression oriented language (in contrast to more typical procedure-oriented languages), but unlike APL, it completely lacks operators. At least in most aspects, it is a case of pure functional programming.
Mooers trademarked the name TRAC in an effort to maintain his control over the definition of the language, an unusual and pioneering action at the time.[1] (http://tracfoundation.org/mooers/law/exchange.htm) At one point, he brought a intellectual-property-infringement suit against DEC, alleging that a contract to deliver a mini-computer with a TRAC interpreter violated his rights.
There have been various languages inspired by TRAC:
- one perceived shortcoming of TRAC was lack of full extensibility: some TRAC primitive functions are sensitive to the distinction between a null (zero-character) argument and a nonexistent (non-delimited) one, but beyond its last non-null argument, a user-defined function cannot make the distinction. SAM76 was a 1976 implementation of a TRAC-like language, for pre-IBM-PC microprocessor-based personal computers, with that limitation avoided.
- one survived as least as late as 1996: Russell Nelson implemented an EMACS extension language named MINT (MINT Is Not TRAC).
External links
- TRAC Foundation (http://tracfoundation.org)