Gforth Manual

Table of Contents

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This manual is for Gforth (version 0.7.0, November 2, 2008), a fast and portable implementation of the ANS Forth language. It serves as reference manual, but it also contains an introduction to Forth and a Forth tutorial.

Copyright © 1995, 1996, 1997, 1998, 2000, 2003, 2004,2005,2006,2007,2008 Free Software Foundation, Inc.

Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.1 or any later version published by the Free Software Foundation; with no Invariant Sections, with the Front-Cover texts being “A GNU Manual,” and with the Back-Cover Texts as in (a) below. A copy of the license is included in the section entitled “GNU Free Documentation License.”

(a) The FSF's Back-Cover Text is: “You have freedom to copy and modify this GNU Manual, like GNU software. Copies published by the Free Software Foundation raise funds for GNU development.”

--- The Detailed Node Listing ---

Gforth Environment

Forth Tutorial

An Introduction to ANS Forth

Forth Words


Stack Manipulation


Control Structures

Defining Words

User-defined Defining Words

Interpretation and Compilation Semantics

Tokens for Words

Compiling words

The Text Interpreter

Word Lists


Search Paths

Other I/O


Gforth locals


Object-oriented Forth

The objects.fs model

The oof.fs model

The mini-oof.fs model

Programming Tools

C Interface

Assembler and Code Words


ANS conformance

The Core Words

The optional Block word set

The optional Double Number word set

The optional Exception word set

The optional Facility word set

The optional File-Access word set

The optional Floating-Point word set

The optional Locals word set

The optional Memory-Allocation word set

The optional Programming-Tools word set

The optional Search-Order word set

Emacs and Gforth

Image Files

Fully Relocatable Image Files




Cross Compiler