PRAXIS, High Level Computer Language for System Applications

1 - Description of program or function: PRAXIS is a systems implementation programming language designed especially for control and communications programming. It is a modern, strongly-typed, block-structured language similar to PASCAL but with extensions and features particular to control systems applications. The software consists of three PRAXIS compilers and three associated support utilities - the PRAXIS RMS-11 Interface, a set of procedures, functions, and type declarations which allow PRAXIS programs to interface to the RMS-11 Input/Output system under VAX/VMS and the RSX-11M systems; TEXTIO, character I/O software for terminal and line-printer text operations; and UNPASCAL, a program which translates simple PASCAL programs into PRAXIS. The compilers included are: a VAX/VMS version which generates VAX code, a VAX/VMS version which generates PDP11 codes, and a PDP11/RSX-11M version which generates PDP11 code. NESC Edition B of PRAXIS is designated as Version 7.3 by the contributors. The PDP11 compiler is not supported and has not been changed since February 1982. 2 - Method of solution: The PRAXIS compilers use LALR parsing technique to generate an intermediate machine-independent code. This is then processed using templates for the target computer to generate actual machine instructions