CREXX

Release Documentation - crexx-HF001 - Sept 2022

REXX Language Implementation Architecture

Project to develop a modern ground up implementation of a REXX interpreter and compiler, and experiments with language improvements. To implement REXX using the best language tools available today, including the LLVM Compiler Infrastructure. These tools will allow a REXX compiler to be produced supporting multiple backends (including 64 bit architectures).

One aspect of the project is to revisit the REXX language - what can be improved? And most importantly how can it be improved while keeping the essence of REXX:

to make programming easier than before

CREXX will be targeted to run on VM/370 (a nod to REXX’s heritage) and it will also run on Linux, Windows, OSX, and z/Architecture.

Wiki Based Documentation

This represents the latest thoughts, aims, architecture, designs and details; some of this may have been built, some things may have been built to older designs and some may just be a future wish. This is the place where we are developing the cREXX Architecture.

Key Links:

• Wiki Home
• Issues
• Discussions
• Project Kanban
• And of course the Github Home

Release Based Documentation

This is the “As Built” documentation, specific to its release; the current develop branch version is availabke as a website.

The documentation is stored in the code repository/branch under the /doc directory as markdown files.

Current Component User Documentation

crexx-HF001

Running a REXX program

Assuming test.rexx is the source program

rxc test
rxas test.rxas
rxvm test.rxbin

Compiler

Handles REXX Level B subset

• Assignments / Expressions
• SAY
• IF/THEN/ELSE
• DO/TO/BY
• ADDRESS

Type

rxc -h 

for command format / options

Assembler

See REXX Assembler Specification.

Type

rxas -h 

for command format / options

Type

rxas -i 

for list of assembler instructions

Disassembler

Type

rxdas -h 

for command format / options

VM/Interpreter

Type

rxvm -h 

for command format / options