Actor (programming language)

{{Short description|Programming language}}

{{More citations needed|date=April 2010}}

The Actor programming language was invented by Charles Duff of The Whitewater Group in 1988. It was an offshoot of some object-oriented extensions to the Forth language he had been working on.{{Cite book |last=Ziff Davis Inc |url=https://books.google.com/books?id=f7GkbOJrVekC&dq=charles+duff+actor+programming&pg=PT346 |title=PC Mag |date=1991-03-26 |publisher=Ziff Davis, Inc. |language=en}}

Actor is a pure object-oriented language in the style of Smalltalk. Like Smalltalk, everything is an object, including small integers. A Baker semi-space garbage collector is used, along with (in memory-constrained Windows 2.1 days) a software virtual memory system that swaps objects. A token threaded interpreter,{{Cite book |last=InfoWorld Media Group |url=https://books.google.com/books?id=X1AEAAAAMBAJ&q=Whitewater+Group+actor&pg=PA45 |title=InfoWorld |date=1991-02-25 |publisher=InfoWorld Media Group, Inc. |language=en}} written in 16-bit x86 assembly language, executes compiled code.

Actor only was released for Microsoft Windows 2.1 and 3.0. Actor used a pure object-oriented framework over native operating system calls as its basic GUI architecture. This allows an Actor application to look and feel exactly like a Windows application written in C, but with all the advantages of an interactive Smalltalk-like development environment. Both a downside and upside to this architecture is a tight coupling to the Windows architecture, with a thin abstraction layer into objects. This allows direct use of the rich Windows OS API, but also makes it nearly impossible to support any other OS without a significant rewrite of the application framework.

A demo of Actor was shown in an episode of Computer Chronicles.{{Citation |title=Computer Chronicles. Episode 718. Programming Languages |date=1990-03-01 |url=http://archive.org/details/programming_2 |access-date=2022-07-10}}