Many of the words below are just mentioned, without much indication what they do. You can find out more by klicking on the word in the Web version of this document, by typing "help " in Gforth, or by clicking on the word in the word index.

This text mentions words that appear the first time in the documentation; some have been available earlier, but were not documented.

Stability

It is now documented which words are intended to be permanently supported, and which are not; see Stability Goals.

Headline features

No longer documented words

Many of these words are still in Gforth 1.0, but they may be removed in the future.

Other additional features

• You can use the return stack interpretively (except for passing data into or out of INCLUDED, EVALUATE etc.)

• help shows the documentation of words, or documentation nodes. Other words providing information: authors license.

• Boolean flags: select

• Arithmetic words:

• Stack Manipulation:

• Dictionary allocation: ->here w, l, x, xd, a, mem, save-mem-dict

• Heap allocation: save-mem extend-mem free-mem-var. Growable buffers: buffer% init-buffer adjust-buffer.

• Memory access:

• Xchars: xc@ xc@+? xc!+ xc-width xhold xc, invalid-char

• String and character constants: newline #tab #lf #cr #ff #bs #del #bell #esc #eof

• Strings: string-suffix? scan scan-back skip $split nosplit? safe/string insert delete cstring>sstring capscompare capsstring-prefix? capssearch s+ append

• Redirect printing words to a string: >string-execute $tmp

• $trings (String representation with automatic memory management): `$! $@ $@len $!len $+!len $del $ins $+! c$+! $free $init $iter $over $exec $. $slurp $slurp-file $+slurp $+slurp-file $variable`

• $tring arrays: `$[] $[]! $[]+! $+[]! $[]@ $[]# $[]map $[]slurp $[]slurp-file $[]. $[]free $[]variable`

• Internationalization and localization: l" locales native@ locale@ program default locale-csv-out locale-csv .locale-csv locale! locale:

• Substitution in strings: macros-wordlist replaces replacer: .substitute $substitute substitute unescape $unescape

• Counted strings: place string,

• Control flow

• Defining words: avariable buffer: aconstant

• No-ops: [noop] noop

• Name tokens: find-name-in latestnt xt>name traverse-wordlist name>interpret name>compile compile-only? obsolete? name>link

• Literal compilers: lit, aliteral 2lit, flit, slit,

• Word definition and text-interpreter status: in-colon-def? state

• Conditional and looping compilation: [DEFINED] [UNDEFINED] [I] INT-[I]

• Text interpreter hooks: before-line before-word line-end-hook

• Input stream: string-parse

• Wordlists: in-wordlist in cs-wordlist cs-vocabulary .voc wordlist-words mwords map-vocs

• String to number conversion: >float1 holds

• Environmental queries: max-xchar xchar-maxmem os-type

• File inclusion: \\\ .included

• General file handling: +fmode file-eof?

• Redirection: outfile-id infile-id

• Directories: basename dirname open-dir read-dir close-dir filename-match get-dir set-dir =mkdir mkdir-parents

• Search paths: absolute-file? .fpath file>fpath file>path

• Simple numeric output: h. dec.r

• Floating-point output: fp. e. e.p e.exact

• Terminal output, in particular colors: at-deltaxy default-color error-color error-hl-inv error-hl-ul warning-color info-color success-color input-color status-color compile-color postpone-color light-mode dark-mode uncolored-mode magenta-input default-input

• Single-key input: key-ior xkey? ekey>xchar k-enter k-backspace k-tab k-winch k-pause k-mute k-volup k-voldown k-sel k-eof fkey. simple-fkey-string

• CSV input: read-csv csv-separator csv-quote .quoted-csv

• Locals: {: | :} z: z^ xt: @localn f@localn !localn lp+n lp+!

• Mini-OOF2 (a little larger than Mini-OOF, but much smaller than the others; Gforth-specific): >o o> rec-moof2 :method

• Regular Expressions: (( )) charclass +char -char ..char +chars +class -class c? -c? \d \s .? -\d -\s \^ \$ str=? =" {** **} {++ ++} {* *} {+ +} // {{ || }} \( \) \0 s>> >> << <<" s// //s //o //g FORK JOIN ` `? -`

• Examining compiled code: xt-simple-see xt-see-code

• Debugging words: debug-fid once ~~bt ~~1bt ??? WTF?? !!FiXME!! replace-word ~~Variable ~~Value +ltrace -ltrace #loc

• Code Coverage and Execution Frequency: .coverage annotate-cov bw-cover color-cover save-cov load-cov nocov[ ]nocov cov+ ?cov+ cov% .cover-raw

• Definitions in assembly language: abi-code ;abi-code

• Disassembler: disasm2 intel-syntax at&t-syntax disasm disasm-gdb

• Keeping track of Time: ns >time&date&tz ntime

• Image saving and startup: 'image process-option

• MINOS2: actor widget caller-w active-w act-name$ clicked scrolled touchdown touchup ukeyed ekeyed ?inside focus defocus entered left show hide get set show-you parent-w act name$ x y w h d gap baseline kerning raise border borderv bordert borderl w-color draw-init draw split lastfit hglue dglue vglue hglue@ dglue@ vglue@ xywh xywhd !resize !size dispose-widget .widget par-split resized >animate color: new-color: text-color: text-emoji-color: fade-color: text-emoji-fade-color: re-color re-text-color re-emoji-color re-fade-color re-text-emoji-fade-color vp-top vp-bottom vp-left vp-right vp-reslide vp-needed

• Other words: f.s-precision fclearstack sh-get synonym out

Gforth EC non-news

We have not done Gforth EC work since Gforth 0.7. We recommend using Gforth 0.7 for Gforth EC, but welcome bug or success reports for Gforth EC in our git head.

Requirements:
  At run-time requires libtool and gcc (for the libcc C interface) and
                       gdb (for the disassembler (SEE)) on some platforms.
Installation:
  support for DESTDIR, POST_INSTALL, INSTALL_SCRIPT
  automatic performance tuning on building (--enable-force-reg unnecessary)
  report performance and functionality problems at end of "make"
  autogen.sh now exists
License:
  Changed to GPLv3
Bug fixes
  Now works with address-space randomization.
  The single-step debugger works again in some engines.
  Many others.
Ports:
  AMD64, ARM, IA-64 (Itanium): better performance
  PPC, PPC64: disassembler and assembler
  Gforth EC: R8C, 4stack, misc, 8086 work
  MacOS X: better support
Invocation:
  New flags --ignore-async-signals, --vm-commit (default overcommit)
            --print-sequences
Forth 200x:
  X:extension-query: produce true for all implemented extensions
  X:required REQUIRED etc. (not new)
  X:defined: [DEFINED] and [UNDEFINED]
  X:parse-name: PARSE-NAME (new name)
  X:deferred: deferred words (new: DEFER@ DEFER! ACTION-OF)
  X:structures: +FIELD FIELD: FFIELD: CFIELD: etc.
  X:ekeys: new: EKEY>FKEY K-SHIFT-MASK K-CTRL-MASK K-ALT-MASK K-F1...K-F12
  X:fp-stack (not new)
  X:number-prefixes (partially new, see below)
Number prefixes:
  0x is a hex prefix: 0xff and 0XfF now produces (decimal) 255
  # is a decimal prefix: #10 now produces (decimal) 10
  Signs after the number prefix are now accepted, e.g, #-50.
  ' now only handles a single (x)char: 'ab is no longer accepted, 
                                       'a' now produces (decimal) 97
Unicode support (currently supports only uniform encoding):
  added xchars words for dealing with variable-width multi-byte characters
  provide 8bit (ISO Latin 1) and UTF-8 support for xchars
New words:
  \C C-FUNCTION C-LIBRARY END-C-LIBRARY C-LIBRARY-NAME (libcc C interface)
  LIB-ERROR (complements OPEN-LIB)
  OUTFILE-EXECUTE INFILE-EXECUTE BASE-EXECUTE (limited change of global state)
  16-bit and 32-bit memory acces: UW@ UL@ SW@ SL@ W! L! W@ L@ /W /L
  NEXT-ARG SHIFT-ARGS (OS command-line argument processing)
  NOTHROW (for backtrace control)
  FTRUNC FMOD (undocumented)
  SEE-CODE SEE-CODE-RANGE (show generated dynamic native code)
Improvements/changes of existing words:
  S\", .\" now support \l, \m, \z, and limits hex and octal character specs.
  OPEN-FILE with W/O no longer creates or truncates files (no compat. file)
  OPEN-LIB now understands ~ at the start, like OPEN-FILE.
  TRY...ENDTRY changed significantly, compatibility files available (see docs).
  The disassembler (DISCODE) can now use gdb to disassemble code
  Uninitialized defered words now give a warning when executed
  Division is floored (disable with "configure --enable-force-cdiv")
  Gforth (not gforth-fast) reports division by zero and overflow on division
    on all platforms.
Newly documented words:
  S>NUMBER? S>UNUMBER?
  EKEY keypress names: K-LEFT  K-RIGHT K-UP K-DOWN K-HOME K-END K-PRIOR
    K-NEXT K-INSERT K-DELETE
  CLEARSTACKS
  FORM
Environment variable GFORTHSYSTEMPREFIX (used by word SYSTEM and friends)
C interface:
  exported symbols now start with "gforth_" (for referencing them from C code)
  libcc C function call interface (requires libtool and gcc at run-time)
    alternative: undocumented libffi-based interface
Libraries:
  depth-changes.fs: report stack depth changes during interpretation
  ans-report.fs now reports CfV extensions
  fsl-util.4th: FSL support files (undocumented)
  regexp.fs for regular expressions (undocumented)
  complex.fs for complex numbers (undocumented)
  fft.fs for Fast Fourier Transform (undocumented)
  wf.fs, a Wiki implementation (undocumented)
  httpd.fs, a web server (undocumented)
  status.fs, show interpreter status in separate xterm (undocumented)
  profile.fs for profiling (undocumented, incomplete)
  endtry-iferror.fs, recover-endtry.fs to ease the TRY change transition
  test/tester.fs: Now works with FP numbers (undocumented)
  test/ttester.fs: Version of tester.fs with improved interface (T{...}T).
 compat library:
  compat/execute-parsing.fs
Speed improvements:
  automatic performance tuning on building
  static stack caching (good speedup on PPC)
  mixed-precision division is now faster
  support for int128 types on AMD64
  workarounds for gcc performance bugs (in particular, PR 15242)
  branch target alignment (good speedup on Alpha).

Bug fixes (in particular, gforth-0.6.2 compiles with gcc-3.3)
New words: LATEST, LATESTXT (LASTXT deprecated)
Operating environment: Added optional support for a C interface built
  on the ffcall libraries (more portable and powerful than the old
  one, but still not documented).  To use it, the ffcall libraries
  have to be installed before building Gforth (see INSTALL).
Miscellaneous: Gforth-fast now uses static superinstructions (some
  speedup on some platforms); generally this is transparent (apart
  from the speedup), but there are lots of command-line options for
  controlling the static superinstruction generation.

Bug fixes (installation on big-endian machines sometimes did not work)

Changes in behaviour:

S": interpreted use now ALLOCATEs the string (they live until BYE).
Long word names (512MB on 32-bit systems) are now supported (change to
  the header format).
New threaded code execution method: primitive-centric (allows the
  following), hybrid direct/indirect threaded (easier portability),
  with dynamic superinstructions (typical speedup on Athlon: factor
  2).  New engine gforth-itc for dealing with some potential
  backwards-compatibility problems (see "Direct or Indirect Threaded?"
  in the manual).

Operating environment:

Default dictionary size is now 4MB.
Large file support on OSs that support them (i.e., files with more
  than 2GB on 32-bit machines).
Gforth can now deal well with broken pipes in most situations.
vi tags files can be built with tags.fs (usage like etags.fs).
gforth.el mostly rewritten.
New image file format.

New words:

Keyboard input: EDIT-LINE K-PRIOR K-NEXT K-DELETE
File input: SLURP-FILE SLURP-FID 
Programming tools: ID. .ID WORDLIST-WORDS SIMPLE-SEE
Conditional execution: [DEFINED] [UNDEFINED]
Defining Words: CONST-DOES> ]]
Input stream: PARSE-WORD EXECUTE-PARSING EXECUTE-PARSING-FILE
String comparison: STR= STR< STRING-PREFIX?
String literals: S\" .\" \"-PARSE
Floating point output: F.RDP F>STR-RDP F>BUF-RDP

Miscellaneous:

Generalized prims2x.fs into Vmgen (see README.vmgen etc.); used the
  new capabilities in prims (e.g., automatic handling of the return
  stack and instruction stream).

Changes in behaviour:

There are now two engines: the fast engine (gforth-fast) is at least
  as fast as gforth in earlier releases; the debugging engine (gforth)
  supports precise backtracing for signals (e.g., illegal memory
  access), but is slower by a factor of 1-2.
Block files now start at block 0 by default (instead of block 1).  If
  you have block files around, prepend 1024 bytes to convert them, or
  do a "1 OFFSET !" to establish the old behaviour.
Gforth now does not translate newlines to LFs on reading.  Instead,
  READ-LINE now interprets LF, CR, and CRLF as newlines.  Newlines on
  output are in the OSs favourite format.
SEE now disassembles primitives (or hex-DUMPs the code if no
  disassembler is available).
>HEAD (aka >NAME) now returns 0 (instead of the nt of ???) on failure.
Syntax of prim changed: stack effects are now surrounded by
  parentheses, tabs are insignificant.

Operating environment:

Gforth now produces a backtrace when catching an exception.
On platforms supporting the Unix 98 SA_SIGINFO semantics, you get more
  precise error reports for SIGSEGV and SIGFPE (e.g., "stack
  underflow" instead of "Invalid memory address").
Gforth now produces exit code 1 if there is an error (i.e., an
  uncaught THROW) in batch processing.
You can use "gforthmi --application ..." to build an image that
  processes the whole command-line when invoked directly (instead of
  through gforth -i).

Ports:

AIX.
20% speedup on 604e under powerpc-unknown-linux-gnu,
19%-29% speedup on Celeron with gcc-2.95.

New words:

Missing ANS Forth words: EKEY EKEY? EKEY>CHAR
Timing words: CPUTIME UTIME
Vector arithmetic: V* FAXPY
FP comparison: F~ABS F~REL
Deferred words: <IS> [IS]
Nested number output: <<# #>>
Exception handling: TRY RECOVER ENDTRY
Directory handling: OPEN-DIR READ-DIR CLOSE-DIR FILENAME-MATCH
Other: ]L PUSH-ORDER

Miscellaneous:

Significant extensions to the manual (added an introduction, among
  other things), many of them due to a new team member: Neal Crook.
Added assemblers and disassemblers for 386, Alpha, MIPS (thanks to
  contributions by Andrew McKewan, Bernd Thallner, and Christian
  Pirker).  Contributions of assemblers and disassemblers for other
  architectures are welcome.

Operating environment:

Path handling: "." at the start of the path represents the directory
  the nearest enclosing file resides in (if there is none: the working
  directory). "~+" indicates the working directory.  The default path
  now has "." in front.
gforth and gforthmi is now more GNU standards compliant (wrt
  command-line options).
New command-line-option: --die-on-signal
Errors are now directed to stderr.
Stdout is now unbuffered, if it is a tty.
User input device redirection (for filters) is now possible.

Ports:

Now runs on IRIX (and other MIPS-based systems without linker-flag -d).
Direct threading now works on PowerPC (20% speedup on 604e).
Better support for m68k (thanks to Andreas Schwab and Jorge Acereda).
It is possible to create executables that contain the image (for
  non-OS systems).

Added a lot of embedded control (EC) stuff. Supported controllers and
small CPUs are Siemens C16x, 8086, 6502, Mixed-Mode's FPGA MISC, Bernd Paysan's
4stack processor. Not finished: ShBoom alias PSC1000, H8, AVR.

New, changed, and removed words:

Renamed F0 to FP0 (avoids unexpected behaviour in hex), added aliases
  SP0, RP0, LP0 (recommended for future use) for S0, R0, L0.
Renamed PARSE-WORD into SWORD (PARSE-WORD is used with the meaning of
  NAME in OpenBoot and dpans6 A.6.2.2008)
Added FPICK (suggested by Julian Noble).
Added EXCEPTION.
S" gforth" ENVIRONMENT? now produces the version-string.
Changed representation of types in struct package, and correspondingly
  changed names.

Miscellaneous:

Plain text documentation is now available in doc/gforth.txt.
Documentation improvements.
Wordlist structure changed.
Added mini-oof.
Reorganized files: added directories and reorganized many files into
  them; renamed files into 8.3 format to work with completely broken
  systems (but there are again some files that won't work there).
Bug fixes.
Various changes without log information only known as mega-patches.
Cross compiler now also supports compilation only for undefined or forward
referenced words. Plugins to support some native code generation
(for PSC1000).
More files in the compat library.

Stack overflow detection by memory protection on most systems
    (allocation with mmap).
gforth.fi is now fully relocatable.
fully relocatable images are now easier to create.
added primitives K and UNDER+.
Win32 support.
Improved support for embedded controllers and other deprived environments.
some bug fixes.
added concept index; other documentation improvements.

Bug fixes

Portability and Installation:

Support architectures with buggy long longs (alpha-dec-osf).
Better support for DOS and other non-Unix systems.
Size changes through the command line are passed to the image (and
saved with savesystem); the preamble specifies an interpreter and is
propagated by save-system.

Tools:

Improved etags support.
more.fs allows output paging.
Added compat/ directory containing ANS implementations of Gforth features.
Added tiny multitasker (tasker.fs).
Added two alternatives for object-oriented programming: oof.fs, objects.fs.
Added ans-report.fs (reports which words are used from which wordset).

New words:

Changed POPEN and PCLOSE to OPEN-PIPE and CLOSE-PIPE.
Added FORM, ROWS, and COLS.
added primitives EMIT-FILE, STDOUT, STDERR.
Added TABLEs (case-sensitive wordlists).
added POSTPONE,.
Added the ability to combine arbitrary interpretation and compilation
semantics (INTERPRET/COMPILE:); state-smart words were generally
rewritten to use that mechanism.

Changes to existing words:

EMIT and TYPE now work through file words (and are redirectable).
HEADER now stores the compilation wordlist in the header and REVEAL
reveals into that wordlist.
changed behaviour of SYSTEM (no longer returns wretval, but puts it in
$?)  added (SYSTEM) ( c_addr u -- wretval wior ).
' and ['] now give an error for compile-only words.

Authors: Anton Ertl, Bernd Paysan
Copyright (C) 1995,1996,1997,1998,2000,2003,2006,2007,2008,2019,2022,2023,2024 Free Software Foundation, Inc.

This file is part of Gforth.

Gforth is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License
as published by the Free Software Foundation, either version 3
of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.#See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program. If not, see http://www.gnu.org/licenses/.


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