hoc, an acronym for High Order Calculator, is an
interpreted programming language
A programming language is a system of notation for writing computer programs. Most programming languages are text-based formal languages, but they may also be graphical. They are a kind of computer language.
The description of a programming l ...
that was used in the 1984 book
The Unix Programming Environment to demonstrate how to build interpreters using
Yacc
Yacc (Yet Another Compiler-Compiler) is a computer program for the Unix operating system developed by Stephen C. Johnson. It is a Look Ahead Left-to-Right Rightmost Derivation (LALR) parser generator, generating a LALR parser (the part of a comp ...
.
hoc was developed by
Brian Kernighan
Brian Wilson Kernighan (; born 1942) is a Canadian computer scientist.
He worked at Bell Labs and contributed to the development of Unix alongside Unix creators Ken Thompson and Dennis Ritchie. Kernighan's name became widely known through co ...
and
Rob Pike
Robert "Rob" Pike (born 1956) is a Canadian programmer and author. He is best known for his work on the Go programming language and at Bell Labs, where he was a member of the Unix team and was involved in the creation of the Plan 9 from Bell Labs ...
as a glorified interactive calculator. Its basic functionality is to evaluate floating-point numerical expressions, e.g., . Then, variables were added, conditionals, loops, user-defined functions, simple IO, and more, using a syntax resembling C.
An improved hoc interpreter was included in
Eighth Edition Research Unix
The term "Research Unix" refers to early versions of the Unix operating system for DEC PDP-7, PDP-11, VAX and Interdata 7/32 and 8/32 computers, developed in the Bell Labs Computing Sciences Research Center (CSRC).
History
The term ''Resear ...
in 1985, but it has not been generally adopted by commercial
Unix
Unix (; trademarked as UNIX) is a family of multitasking, multiuser computer operating systems that derive from the original AT&T Unix, whose development started in 1969 at the Bell Labs research center by Ken Thompson, Dennis Ritchie, a ...
systems or by
Linux
Linux ( or ) is a family of open-so