Limbo (programming language)

Language features

Limbo supports the following features:

• modular programming
• concurrent programming
• strong type checking at compile and run-time
• interprocess communication over typed channels
• automatic garbage collection
• simple abstract data types

Virtual machine

The Dis virtual machine that executes Limbo code is a CISC-like VM, with instructions for arithmetic, control flow, data motion, process creation, synchronizing and communicating between processes, loading modules of code, and support for higher-level data-types: strings, arrays, lists, and communication channels. It uses a hybrid of reference counting and a real-time garbage-collector for cyclic data.

Aspects of the design of Dis were inspired by the AT&T Hobbit microprocessor, as used in the original BeBox.

Examples

Limbo uses Ada-style definitions as in:

name := type value;
name0,name1 : type = value;
name2,name3 : type;
name2 = value;

Hello world

implement Command;

include "sys.m";
    sys: Sys;

include "draw.m";

include "sh.m";

init(nil: ref Draw->Context, nil: list of string)
{
    sys = load Sys Sys->PATH;
    sys->print("Hello World!\n");
}

Books

The 3rd edition of the Inferno operating system and Limbo programming language are described in the textbook Inferno Programming with Limbo (Chichester: John Wiley & Sons, 2003), by Phillip Stanley-Marbell. Another textbook The Inferno Programming Book: An Introduction to Programming for the Inferno Distributed System, by Martin Atkins, Charles Forsyth, Rob Pike and Howard Trickey, was started, but never released.

References

References

1. "Inferno Application Programming". vitanuova.
2. (2000). "Dis Virtual Machine Specification". Vita Nuova.
3. Lorenz Huelsbergen and Phil Winterbottom. (1998). "Very Concurrent Mark and Sweep Garbage Collection without Fine-Grain Synchronization". 1998 International Symposium on Memory Management.