Action programming language

Action! was a programming language, editor and in-memory 6502 Compiler created by Clinton Parker working for Optimized Systems Software and running on the Atari 8-bit family of microcomputers. Its syntax was similar to that of ALGOL 68, and it was well-known for its speed. A library was available as a separate product called the Action! Toolkit.

It was released in 1983 and officially sold as a cartridge and later cracked to disk. ATR format files containing a version which may be run on modern systems under emulation are available on some websites.

= Data Types =

Action! has three numerical Datatypes BYTEs, CARDinals and INTegers. The BYTE datatype is a single unsigned 8-Bit byte, CARD is unsigned and two bytes long, and INT is signed and two bytes. Action! also has CHARs, ARRAYs, POINTERs and user defined TYPEs.

Unfortunately, no floating point support was available, and all data types were static. This meant variables had to be declared ahead of time and no dynamic memory management.

An example of a user-defined TYPE:

TYPE CORD=[CARD x,y] CORD point point.x=42 point.y=23

= Reserved keywords =

AND F1 OR UNTIL =< ( ARRAY FOR POINTER WHILE ) BYTE FUNC PROC XOR # . CARD IF RETURN = > [ CHAR INCLUDE RSH - >= ] DEFINE INT SET * < DO LSH STEP /