version 1.24, 1995/11/15 17:29:07
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version 1.40, 1996/11/11 16:59:16
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Line 7
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@comment %**end of header (This is for running Texinfo on a region.) |
@comment %**end of header (This is for running Texinfo on a region.) |
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@ifinfo |
@ifinfo |
This file documents Gforth 0.1 |
This file documents Gforth 0.2 |
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Copyright @copyright{} 1995 Free Software Foundation, Inc. |
Copyright @copyright{} 1995,1996 Free Software Foundation, Inc. |
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Permission is granted to make and distribute verbatim copies of |
Permission is granted to make and distribute verbatim copies of |
this manual provided the copyright notice and this permission notice |
this manual provided the copyright notice and this permission notice |
Line 41 Copyright @copyright{} 1995 Free Softwar
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Line 41 Copyright @copyright{} 1995 Free Softwar
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@sp 10 |
@sp 10 |
@center @titlefont{Gforth Manual} |
@center @titlefont{Gforth Manual} |
@sp 2 |
@sp 2 |
@center for version 0.1 |
@center for version 0.2 |
@sp 2 |
@sp 2 |
@center Anton Ertl |
@center Anton Ertl |
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@center Bernd Paysan |
@sp 3 |
@sp 3 |
@center This manual is under construction |
@center This manual is under construction |
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@comment The following two commands start the copyright page. |
@comment The following two commands start the copyright page. |
@page |
@page |
@vskip 0pt plus 1filll |
@vskip 0pt plus 1filll |
Copyright @copyright{} 1995 Free Software Foundation, Inc. |
Copyright @copyright{} 1995,1996 Free Software Foundation, Inc. |
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@comment !! Published by ... or You can get a copy of this manual ... |
@comment !! Published by ... or You can get a copy of this manual ... |
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Line 76 Copyright @copyright{} 1995 Free Softwar
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Line 77 Copyright @copyright{} 1995 Free Softwar
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@node Top, License, (dir), (dir) |
@node Top, License, (dir), (dir) |
@ifinfo |
@ifinfo |
Gforth is a free implementation of ANS Forth available on many |
Gforth is a free implementation of ANS Forth available on many |
personal machines. This manual corresponds to version 0.1. |
personal machines. This manual corresponds to version 0.2. |
@end ifinfo |
@end ifinfo |
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@menu |
@menu |
Line 85 personal machines. This manual correspon
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Line 86 personal machines. This manual correspon
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* Other Books:: Things you might want to read |
* Other Books:: Things you might want to read |
* Invocation:: Starting Gforth |
* Invocation:: Starting Gforth |
* Words:: Forth words available in Gforth |
* Words:: Forth words available in Gforth |
|
* Tools:: Programming tools |
* ANS conformance:: Implementation-defined options etc. |
* ANS conformance:: Implementation-defined options etc. |
* Model:: The abstract machine of Gforth |
* Model:: The abstract machine of Gforth |
|
* Integrating Gforth:: Forth as scripting language for applications. |
* Emacs and Gforth:: The Gforth Mode |
* Emacs and Gforth:: The Gforth Mode |
* Internals:: Implementation details |
* Internals:: Implementation details |
* Bugs:: How to report them |
* Bugs:: How to report them |
* Pedigree:: Ancestors of Gforth |
* Origin:: Authors and ancestors of Gforth |
* Word Index:: An item for each Forth word |
* Word Index:: An item for each Forth word |
* Node Index:: An item for each node |
* Node Index:: An item for each node |
@end menu |
@end menu |
Line 598 Loads the Forth image @var{file} instead
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Line 601 Loads the Forth image @var{file} instead
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|
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@item --path @var{path} |
@item --path @var{path} |
@item -p @var{path} |
@item -p @var{path} |
Uses @var{path} for searching the image file and Forth source code |
Uses @var{path} for searching the image file and Forth source code files |
files instead of the default in the environment variable |
instead of the default in the environment variable @code{GFORTHPATH} or |
@code{GFORTHPATH} or the path specified at installation time (typically |
the path specified at installation time (e.g., |
@file{/usr/local/lib/gforth:.}). A path is given as a @code{:}-separated |
@file{/usr/local/share/gforth/0.2.0:.}). A path is given as a list of |
list. |
directories, separated by @samp{:} (on Unix) or @samp{;} (on other OSs). |
|
|
@item --dictionary-size @var{size} |
@item --dictionary-size @var{size} |
@item -m @var{size} |
@item -m @var{size} |
Line 660 the user initialization file @file{.gfor
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Line 663 the user initialization file @file{.gfor
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option @code{--no-rc} is given; this file is first searched in @file{.}, |
option @code{--no-rc} is given; this file is first searched in @file{.}, |
then in @file{~}, then in the normal path (see above). |
then in @file{~}, then in the normal path (see above). |
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@node Words, ANS conformance, Invocation, Top |
@node Words, Tools, Invocation, Top |
@chapter Forth Words |
@chapter Forth Words |
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@menu |
@menu |
Line 671 then in @file{~}, then in the normal pat
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Line 674 then in @file{~}, then in the normal pat
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* Control Structures:: |
* Control Structures:: |
* Locals:: |
* Locals:: |
* Defining Words:: |
* Defining Words:: |
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* Tokens for Words:: |
* Wordlists:: |
* Wordlists:: |
* Files:: |
* Files:: |
* Blocks:: |
* Blocks:: |
Line 753 double sized signed integer
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Line 757 double sized signed integer
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@item ud |
@item ud |
double sized unsigned integer |
double sized unsigned integer |
@item r |
@item r |
Float |
Float (on the FP stack) |
@item a_ |
@item a_ |
Cell-aligned address |
Cell-aligned address |
@item c_ |
@item c_ |
Char-aligned address (note that a Char is two bytes in Windows NT) |
Char-aligned address (note that a Char may have two bytes in Windows NT) |
@item f_ |
@item f_ |
Float-aligned address |
Float-aligned address |
@item df_ |
@item df_ |
Line 770 Execution token, same size as Cell
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Line 774 Execution token, same size as Cell
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Wordlist ID, same size as Cell |
Wordlist ID, same size as Cell |
@item f83name |
@item f83name |
Pointer to a name structure |
Pointer to a name structure |
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@item " |
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string in the input stream (not the stack). The terminating character is |
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a blank by default. If it is not a blank, it is shown in @code{<>} |
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quotes. |
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@end table |
@end table |
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@node Arithmetic, Stack Manipulation, Notation, Words |
@node Arithmetic, Stack Manipulation, Notation, Words |
Line 847 The format of floating point numbers rec
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Line 856 The format of floating point numbers rec
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interpreter is: a signed decimal number, possibly containing a decimal |
interpreter is: a signed decimal number, possibly containing a decimal |
point (@code{.}), followed by @code{E} or @code{e}, optionally followed |
point (@code{.}), followed by @code{E} or @code{e}, optionally followed |
by a signed integer (the exponent). E.g., @code{1e} ist the same as |
by a signed integer (the exponent). E.g., @code{1e} ist the same as |
@code{+1.0e+1}. Note that a number without @code{e} |
@code{+1.0e+0}. Note that a number without @code{e} |
is not interpreted as floating-point number, but as double (if the |
is not interpreted as floating-point number, but as double (if the |
number contains a @code{.}) or single precision integer. Also, |
number contains a @code{.}) or single precision integer. Also, |
conversions between string and floating point numbers always use base |
conversions between string and floating point numbers always use base |
Line 1140 system that only supplies @code{THEN} is
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Line 1149 system that only supplies @code{THEN} is
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Forth's @code{THEN} has the meaning 2b, whereas @code{THEN} in Pascal |
Forth's @code{THEN} has the meaning 2b, whereas @code{THEN} in Pascal |
and many other programming languages has the meaning 3d.] |
and many other programming languages has the meaning 3d.] |
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We also provide the words @code{?dup-if} and @code{?dup-0=-if}, so you |
Gforth also provides the words @code{?dup-if} and @code{?dup-0=-if}, so |
can avoid using @code{?dup}. |
you can avoid using @code{?dup}. Using these alternatives is also more |
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efficient than using @code{?dup}. Definitions in plain standard Forth |
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for @code{ENDIF}, @code{?DUP-IF} and @code{?DUP-0=-IF} are provided in |
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@file{compat/control.fs}. |
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@example |
@example |
@var{n} |
@var{n} |
Line 1233 arithmetic). This behaviour is usually n
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Line 1245 arithmetic). This behaviour is usually n
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Gforth offers @code{+DO} and @code{U+DO} (as replacements for |
Gforth offers @code{+DO} and @code{U+DO} (as replacements for |
@code{?DO}), which do not enter the loop if @var{start} is greater than |
@code{?DO}), which do not enter the loop if @var{start} is greater than |
@var{limit}; @code{+DO} is for signed loop parameters, @code{U+DO} for |
@var{limit}; @code{+DO} is for signed loop parameters, @code{U+DO} for |
unsigned loop parameters. These words can be implemented easily on |
unsigned loop parameters. |
standard systems, so using them does not make your programs hard to |
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port; e.g.: |
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@example |
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: +DO ( compile-time: -- do-sys; run-time: n1 n2 -- ) |
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POSTPONE over POSTPONE min POSTPONE ?DO ; immediate |
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@end example |
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@code{LOOP} can be replaced with @code{@var{n} +LOOP}; this updates the |
@code{LOOP} can be replaced with @code{@var{n} +LOOP}; this updates the |
index by @var{n} instead of by 1. The loop is terminated when the border |
index by @var{n} instead of by 1. The loop is terminated when the border |
Line 1267 between @var{limit+1} and @var{limit} is
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Line 1273 between @var{limit+1} and @var{limit} is
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@code{ 0 0 -DO i . 1 -LOOP} prints nothing |
@code{ 0 0 -DO i . 1 -LOOP} prints nothing |
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Another alternative is @code{@var{n} S+LOOP}, where the negative |
Unfortunately, @code{+DO}, @code{U+DO}, @code{-DO}, @code{U-DO} and |
case behaves symmetrical to the positive case: |
@code{-LOOP} are not in the ANS Forth standard. However, an |
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implementation for these words that uses only standard words is provided |
@code{-2 0 -DO i . -1 S+LOOP} prints @code{0 -1} |
in @file{compat/loops.fs}. |
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The loop is terminated when the border between @var{limit@minus{}sgn(n)} |
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and @var{limit} is crossed. Unfortunately, neither @code{-LOOP} nor |
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@code{S+LOOP} are part of the ANS Forth standard, and they are not easy |
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to implement using standard words. If you want to write standard |
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programs, just avoid counting down. |
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@code{?DO} can also be replaced by @code{DO}. @code{DO} always enters |
@code{?DO} can also be replaced by @code{DO}. @code{DO} always enters |
the loop, independent of the loop parameters. Do not use @code{DO}, even |
the loop, independent of the loop parameters. Do not use @code{DO}, even |
Line 1299 This is the preferred loop of native cod
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Line 1299 This is the preferred loop of native cod
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lazy to optimize @code{?DO} loops properly. In Gforth, this loop |
lazy to optimize @code{?DO} loops properly. In Gforth, this loop |
iterates @var{n+1} times; @code{i} produces values starting with @var{n} |
iterates @var{n+1} times; @code{i} produces values starting with @var{n} |
and ending with 0. Other Forth systems may behave differently, even if |
and ending with 0. Other Forth systems may behave differently, even if |
they support @code{FOR} loops. |
they support @code{FOR} loops. To avoid problems, don't use @code{FOR} |
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loops. |
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@node Arbitrary control structures, Calls and returns, Counted Loops, Control Structures |
@node Arbitrary control structures, Calls and returns, Counted Loops, Control Structures |
@subsection Arbitrary control structures |
@subsection Arbitrary control structures |
Line 1335 doc-else
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Line 1336 doc-else
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doc-while |
doc-while |
doc-repeat |
doc-repeat |
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Gforth adds some more control-structure words: |
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doc-endif |
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doc-?dup-if |
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doc-?dup-0=-if |
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Counted loop words constitute a separate group of words: |
Counted loop words constitute a separate group of words: |
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doc-?do |
doc-?do |
Line 1345 doc-u-do
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Line 1352 doc-u-do
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doc-do |
doc-do |
doc-for |
doc-for |
doc-loop |
doc-loop |
doc-s+loop |
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doc-+loop |
doc-+loop |
doc--loop |
doc--loop |
doc-next |
doc-next |
Line 1410 while
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Line 1416 while
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repeat |
repeat |
@end example |
@end example |
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That's much easier to read, isn't it? Of course, @code{BEGIN} and |
That's much easier to read, isn't it? Of course, @code{REPEAT} and |
@code{WHILE} are predefined, so in this example it would not be |
@code{WHILE} are predefined, so in this example it would not be |
necessary to define them. |
necessary to define them. |
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Line 1735 E.g., a definition using @code{TO} might
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Line 1741 E.g., a definition using @code{TO} might
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: strcmp @{ addr1 u1 addr2 u2 -- n @} |
: strcmp @{ addr1 u1 addr2 u2 -- n @} |
u1 u2 min 0 |
u1 u2 min 0 |
?do |
?do |
addr1 c@ addr2 c@ - ?dup |
addr1 c@@ addr2 c@@ - |
if |
?dup-if |
unloop exit |
unloop exit |
then |
then |
addr1 char+ TO addr1 |
addr1 char+ TO addr1 |
Line 1758 are initialized with the right value for
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Line 1764 are initialized with the right value for
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addr1 addr2 |
addr1 addr2 |
u1 u2 min 0 |
u1 u2 min 0 |
?do @{ s1 s2 @} |
?do @{ s1 s2 @} |
s1 c@ s2 c@ - ?dup |
s1 c@@ s2 c@@ - |
if |
?dup-if |
unloop exit |
unloop exit |
then |
then |
s1 char+ s2 char+ |
s1 char+ s2 char+ |
Line 1932 stack easier.
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Line 1938 stack easier.
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The whole definition must be in one line. |
The whole definition must be in one line. |
@end itemize |
@end itemize |
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Locals defined in this way behave like @code{VALUE}s |
Locals defined in this way behave like @code{VALUE}s (@xref{Simple |
(@xref{Values}). I.e., they are initialized from the stack. Using their |
Defining Words}). I.e., they are initialized from the stack. Using their |
name produces their value. Their value can be changed using @code{TO}. |
name produces their value. Their value can be changed using @code{TO}. |
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Since this syntax is supported by Gforth directly, you need not do |
Since this syntax is supported by Gforth directly, you need not do |
anything to use it. If you want to port a program using this syntax to |
anything to use it. If you want to port a program using this syntax to |
another ANS Forth system, use @file{anslocal.fs} to implement the syntax |
another ANS Forth system, use @file{compat/anslocal.fs} to implement the |
on the other system. |
syntax on the other system. |
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Note that a syntax shown in the standard, section A.13 looks |
Note that a syntax shown in the standard, section A.13 looks |
similar, but is quite different in having the order of locals |
similar, but is quite different in having the order of locals |
Line 1958 programs harder to read, and easier to m
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Line 1964 programs harder to read, and easier to m
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merit of this syntax is that it is easy to implement using the ANS Forth |
merit of this syntax is that it is easy to implement using the ANS Forth |
locals wordset. |
locals wordset. |
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@node Defining Words, Wordlists, Locals, Words |
@node Defining Words, Tokens for Words, Locals, Words |
@section Defining Words |
@section Defining Words |
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@menu |
@menu |
* Values:: |
* Simple Defining Words:: |
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* Colon Definitions:: |
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* User-defined Defining Words:: |
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* Supplying names:: |
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* Interpretation and Compilation Semantics:: |
@end menu |
@end menu |
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@node Values, , Defining Words, Defining Words |
@node Simple Defining Words, Colon Definitions, Defining Words, Defining Words |
@subsection Values |
@subsection Simple Defining Words |
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doc-constant |
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doc-2constant |
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doc-fconstant |
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doc-variable |
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doc-2variable |
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doc-fvariable |
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doc-create |
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doc-user |
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doc-value |
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doc-to |
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doc-defer |
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doc-is |
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@node Colon Definitions, User-defined Defining Words, Simple Defining Words, Defining Words |
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@subsection Colon Definitions |
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@example |
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: name ( ... -- ... ) |
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word1 word2 word3 ; |
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@end example |
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creates a word called @code{name}, that, upon execution, executes |
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@code{word1 word2 word3}. @code{name} is a @dfn{(colon) definition}. |
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The explanation above is somewhat superficial. @xref{Interpretation and |
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Compilation Semantics} for an in-depth discussion of some of the issues |
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involved. |
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doc-: |
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doc-; |
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@node User-defined Defining Words, Supplying names, Colon Definitions, Defining Words |
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@subsection User-defined Defining Words |
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You can create new defining words simply by wrapping defining-time code |
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around existing defining words and putting the sequence in a colon |
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definition. |
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If you want the words defined with your defining words to behave |
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differently from words defined with standard defining words, you can |
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write your defining word like this: |
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@example |
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: def-word ( "name" -- ) |
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Create @var{code1} |
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DOES> ( ... -- ... ) |
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@var{code2} ; |
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def-word name |
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@end example |
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Technically, this fragment defines a defining word @code{def-word}, and |
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a word @code{name}; when you execute @code{name}, the address of the |
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body of @code{name} is put on the data stack and @var{code2} is executed |
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(the address of the body of @code{name} is the address @code{HERE} |
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returns immediately after the @code{CREATE}). |
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In other words, if you make the following definitions: |
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@example |
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: def-word1 ( "name" -- ) |
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Create @var{code1} ; |
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: action1 ( ... -- ... ) |
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@var{code2} ; |
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def-word name1 |
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@end example |
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Using @code{name1 action1} is equivalent to using @code{name}. |
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E.g., you can implement @code{Constant} in this way: |
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@example |
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: constant ( w "name" -- ) |
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create , |
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DOES> ( -- w ) |
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@@ ; |
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@end example |
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When you create a constant with @code{5 constant five}, first a new word |
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@code{five} is created, then the value 5 is laid down in the body of |
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@code{five} with @code{,}. When @code{five} is invoked, the address of |
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the body is put on the stack, and @code{@@} retrieves the value 5. |
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In the example above the stack comment after the @code{DOES>} specifies |
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the stack effect of the defined words, not the stack effect of the |
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following code (the following code expects the address of the body on |
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the top of stack, which is not reflected in the stack comment). This is |
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the convention that I use and recommend (it clashes a bit with using |
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locals declarations for stack effect specification, though). |
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@subsubsection Applications of @code{CREATE..DOES>} |
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You may wonder how to use this feature. Here are some usage patterns: |
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When you see a sequence of code occurring several times, and you can |
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identify a meaning, you will factor it out as a colon definition. When |
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you see similar colon definitions, you can factor them using |
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@code{CREATE..DOES>}. E.g., an assembler usually defines several words |
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that look very similar: |
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@example |
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: ori, ( reg-taget reg-source n -- ) |
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0 asm-reg-reg-imm ; |
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: andi, ( reg-taget reg-source n -- ) |
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1 asm-reg-reg-imm ; |
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@end example |
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This could be factored with: |
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@example |
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: reg-reg-imm ( op-code -- ) |
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create , |
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DOES> ( reg-taget reg-source n -- ) |
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@@ asm-reg-reg-imm ; |
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0 reg-reg-imm ori, |
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1 reg-reg-imm andi, |
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@end example |
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Another view of @code{CREATE..DOES>} is to consider it as a crude way to |
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supply a part of the parameters for a word (known as @dfn{currying} in |
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the functional language community). E.g., @code{+} needs two |
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parameters. Creating versions of @code{+} with one parameter fixed can |
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be done like this: |
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@example |
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: curry+ ( n1 -- ) |
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create , |
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DOES> ( n2 -- n1+n2 ) |
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@@ + ; |
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3 curry+ 3+ |
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-2 curry+ 2- |
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@end example |
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@subsubsection The gory details of @code{CREATE..DOES>} |
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doc-does> |
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This means that you need not use @code{CREATE} and @code{DOES>} in the |
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same definition; E.g., you can put the @code{DOES>}-part in a separate |
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definition. This allows us to, e.g., select among different DOES>-parts: |
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@example |
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: does1 |
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DOES> ( ... -- ... ) |
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... ; |
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: does2 |
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DOES> ( ... -- ... ) |
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... ; |
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: def-word ( ... -- ... ) |
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create ... |
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IF |
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does1 |
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ELSE |
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does2 |
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ENDIF ; |
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@end example |
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In a standard program you can apply a @code{DOES>}-part only if the last |
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word was defined with @code{CREATE}. In Gforth, the @code{DOES>}-part |
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will override the behaviour of the last word defined in any case. In a |
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standard program, you can use @code{DOES>} only in a colon |
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definition. In Gforth, you can also use it in interpretation state, in a |
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kind of one-shot mode: |
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@example |
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CREATE name ( ... -- ... ) |
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@var{initialization} |
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DOES> |
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@var{code} ; |
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@end example |
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This is equivalwent to the standard |
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@example |
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:noname |
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DOES> |
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@var{code} ; |
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CREATE name EXECUTE ( ... -- ... ) |
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@var{initialization} |
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@end example |
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You can get the address of the body of a word with |
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doc->body |
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@node Supplying names, Interpretation and Compilation Semantics, User-defined Defining Words, Defining Words |
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@subsection Supplying names for the defined words |
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By default, defining words take the names for the defined words from the |
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input stream. Sometimes you want to supply the name from a string. You |
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can do this with |
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doc-nextname |
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E.g., |
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@example |
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s" foo" nextname create |
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@end example |
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is equivalent to |
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@example |
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create foo |
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@end example |
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Sometimes you want to define a word without a name. You can do this with |
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doc-noname |
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To make any use of the newly defined word, you need its execution |
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token. You can get it with |
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doc-lastxt |
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E.g., you can initialize a deferred word with an anonymous colon |
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definition: |
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@example |
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Defer deferred |
|
noname : ( ... -- ... ) |
|
... ; |
|
lastxt IS deferred |
|
@end example |
|
|
|
@code{lastxt} also works when the last word was not defined as |
|
@code{noname}. |
|
|
|
The standard has also recognized the need for anonymous words and |
|
provides |
|
|
|
doc-:noname |
|
|
|
This leaves the execution token for the word on the stack after the |
|
closing @code{;}. You can rewrite the last example with @code{:noname}: |
|
@example |
|
Defer deferred |
|
:noname ( ... -- ... ) |
|
... ; |
|
IS deferred |
|
@end example |
|
|
|
@node Interpretation and Compilation Semantics, , Supplying names, Defining Words |
|
@subsection Interpretation and Compilation Semantics |
|
|
|
The @dfn{interpretation semantics} of a word are what the text |
|
interpreter does when it encounters the word in interpret state. It also |
|
appears in some other contexts, e.g., the execution token returned by |
|
@code{' @var{word}} identifies the interpretation semantics of |
|
@var{word} (in other words, @code{' @var{word} execute} is equivalent to |
|
interpret-state text interpretation of @code{@var{word}}). |
|
|
|
The @dfn{compilation semantics} of a word are what the text interpreter |
|
does when it encounters the word in compile state. It also appears in |
|
other contexts, e.g, @code{POSTPONE @var{word}} compiles@footnote{In |
|
standard terminology, ``appends to the current definition''.} the |
|
compilation semantics of @var{word}. |
|
|
|
The standard also talks about @dfn{execution semantics}. They are used |
|
only for defining the interpretation and compilation semantics of many |
|
words. By default, the interpretation semantics of a word are to |
|
@code{execute} its execution semantics, and the compilation semantics of |
|
a word are to @code{compile,} its execution semantics.@footnote{In |
|
standard terminology: The default interpretation semantics are its |
|
execution semantics; the default compilation semantics are to append its |
|
execution semantics to the execution semantics of the current |
|
definition.} |
|
|
|
You can change the compilation semantics into @code{execute}ing the |
|
execution semantics with |
|
|
|
doc-immediate |
|
|
|
You can remove the interpretation semantics of a word with |
|
|
|
doc-compile-only |
|
doc-restrict |
|
|
|
Note that ticking (@code{'}) compile-only words gives an error |
|
(``Interpreting a compile-only word''). |
|
|
@node Wordlists, Files, Defining Words, Words |
Gforth also allows you to define words with arbitrary combinations of |
|
interpretation and compilation semantics. |
|
|
|
doc-interpret/compile: |
|
|
|
This feature was introduced for implementing @code{TO} and @code{S"}. I |
|
recommend that you do not define such words, as cute as they may be: |
|
they make it hard to get at both parts of the word in some contexts. |
|
E.g., assume you want to get an execution token for the compilation |
|
part. Instead, define two words, one that embodies the interpretation |
|
part, and one that embodies the compilation part. |
|
|
|
There is, however, a potentially useful application of this feature: |
|
Providing differing implementations for the default semantics. While |
|
this introduces redundancy and is therefore usually a bad idea, a |
|
performance improvement may be worth the trouble. E.g., consider the |
|
word @code{foobar}: |
|
|
|
@example |
|
: foobar |
|
foo bar ; |
|
@end example |
|
|
|
Let us assume that @code{foobar} is called so frequently that the |
|
calling overhead would take a significant amount of the run-time. We can |
|
optimize it with @code{interpret/compile:}: |
|
|
|
@example |
|
:noname |
|
foo bar ; |
|
:noname |
|
POSTPONE foo POSTPONE bar ; |
|
interpret/compile: foobar |
|
@end example |
|
|
|
This definition has the same interpretation semantics and essentially |
|
the same compilation semantics as the simple definition of |
|
@code{foobar}, but the implementation of the compilation semantics is |
|
more efficient with respect to run-time. |
|
|
|
Some people try to use state-smart words to emulate the feature provided |
|
by @code{interpret/compile:} (words are state-smart if they check |
|
@code{STATE} during execution). E.g., they would try to code |
|
@code{foobar} like this: |
|
|
|
@example |
|
: foobar |
|
STATE @@ |
|
IF ( compilation state ) |
|
POSTPONE foo POSTPONE bar |
|
ELSE |
|
foo bar |
|
ENDIF ; immediate |
|
@end example |
|
|
|
While this works if @code{foobar} is processed only by the text |
|
interpreter, it does not work in other contexts (like @code{'} or |
|
@code{POSTPONE}). E.g., @code{' foobar} will produce an execution token |
|
for a state-smart word, not for the interpretation semantics of the |
|
original @code{foobar}; when you execute this execution token (directly |
|
with @code{EXECUTE} or indirectly through @code{COMPILE,}) in compile |
|
state, the result will not be what you expected (i.e., it will not |
|
perform @code{foo bar}). State-smart words are a bad idea. Simply don't |
|
write them! |
|
|
|
It is also possible to write defining words that define words with |
|
arbitrary combinations of interpretation and compilation semantics (or, |
|
preferably, arbitrary combinations of implementations of the default |
|
semantics). In general, this looks like: |
|
|
|
@example |
|
: def-word |
|
create-interpret/compile |
|
@var{code1} |
|
interpretation> |
|
@var{code2} |
|
<interpretation |
|
compilation> |
|
@var{code3} |
|
<compilation ; |
|
@end example |
|
|
|
For a @var{word} defined with @code{def-word}, the interpretation |
|
semantics are to push the address of the body of @var{word} and perform |
|
@var{code2}, and the compilation semantics are to push the address of |
|
the body of @var{word} and perform @var{code3}. E.g., @code{constant} |
|
can also be defined like this: |
|
|
|
@example |
|
: constant ( n "name" -- ) |
|
create-interpret/compile |
|
, |
|
interpretation> ( -- n ) |
|
@@ |
|
<interpretation |
|
compilation> ( compilation. -- ; run-time. -- n ) |
|
@@ postpone literal |
|
<compilation ; |
|
@end example |
|
|
|
doc-create-interpret/compile |
|
doc-interpretation> |
|
doc-<interpretation |
|
doc-compilation> |
|
doc-<compilation |
|
|
|
Note that words defined with @code{interpret/compile:} and |
|
@code{create-interpret/compile} have an extended header structure that |
|
differs from other words; however, unless you try to access them with |
|
plain address arithmetic, you should not notice this. Words for |
|
accessing the header structure usually know how to deal with this; e.g., |
|
@code{' word >body} also gives you the body of a word created with |
|
@code{create-interpret/compile}. |
|
|
|
@node Tokens for Words, Wordlists, Defining Words, Words |
|
@section Tokens for Words |
|
|
|
This chapter describes the creation and use of tokens that represent |
|
words on the stack (and in data space). |
|
|
|
Named words have interpretation and compilation semantics. Unnamed words |
|
just have execution semantics. |
|
|
|
An @dfn{execution token} represents the execution semantics of an |
|
unnamed word. An execution token occupies one cell. As explained in |
|
section @ref{Supplying names}, the execution token of the last words |
|
defined can be produced with |
|
|
|
short-lastxt |
|
|
|
You can perform the semantics represented by an execution token with |
|
doc-execute |
|
You can compile the word with |
|
doc-compile, |
|
|
|
In Gforth, the abstract data type @emph{execution token} is implemented |
|
as CFA (code field address). |
|
|
|
The interpretation semantics of a named word are also represented by an |
|
execution token. You can get it with |
|
|
|
doc-['] |
|
doc-' |
|
|
|
For literals, you use @code{'} in interpreted code and @code{[']} in |
|
compiled code. Gforth's @code{'} and @code{[']} behave somewhat unusual |
|
by complaining about compile-only words. To get an execution token for a |
|
compiling word @var{X}, use @code{COMP' @var{X} drop} or @code{[COMP'] |
|
@var{X} drop}. |
|
|
|
The compilation semantics are represented by a @dfn{compilation token} |
|
consisting of two cells: @var{w xt}. The top cell @var{xt} is an |
|
execution token. The compilation semantics represented by the |
|
compilation token can be performed with @code{execute}, which consumes |
|
the whole compilation token, with an additional stack effect determined |
|
by the represented compilation semantics. |
|
|
|
doc-[comp'] |
|
doc-comp' |
|
|
|
You can compile the compilation semantics with @code{postpone,}. I.e., |
|
@code{COMP' @var{word} POSTPONE,} is equivalent to @code{POSTPONE |
|
@var{word}}. |
|
|
|
doc-postpone, |
|
|
|
At present, the @var{w} part of a compilation token is an execution |
|
token, and the @var{xt} part represents either @code{execute} or |
|
@code{compile,}. However, don't rely on that kowledge, unless necessary; |
|
we may introduce unusual compilation tokens in the future (e.g., |
|
compilation tokens representing the compilation semantics of literals). |
|
|
|
Named words are also represented by the @dfn{name token}. The abstract |
|
data type @emph{name token} is implemented as NFA (name field address). |
|
|
|
doc-find-name |
|
doc-name>int |
|
doc-name?int |
|
doc-name>comp |
|
doc-name>string |
|
|
|
@node Wordlists, Files, Tokens for Words, Words |
@section Wordlists |
@section Wordlists |
|
|
@node Files, Blocks, Wordlists, Words |
@node Files, Blocks, Wordlists, Words |
Line 2085 probably more appropriate than an assert
|
Line 2553 probably more appropriate than an assert
|
Gforth provides some words for defining primitives (words written in |
Gforth provides some words for defining primitives (words written in |
machine code), and for defining the the machine-code equivalent of |
machine code), and for defining the the machine-code equivalent of |
@code{DOES>}-based defining words. However, the machine-independent |
@code{DOES>}-based defining words. However, the machine-independent |
nature of Gforth poses a few problems: First of all. Gforth runs on |
nature of Gforth poses a few problems: First of all, Gforth runs on |
several architectures, so it can provide no standard assembler. What's |
several architectures, so it can provide no standard assembler. What's |
worse is that the register allocation not only depends on the processor, |
worse is that the register allocation not only depends on the processor, |
but also on the gcc version and options used. |
but also on the @code{gcc} version and options used. |
|
|
The words Gforth offers encapsulate some system dependences (e.g., the |
The words that Gforth offers encapsulate some system dependences (e.g., the |
header structure), so a system-independent assembler may be used in |
header structure), so a system-independent assembler may be used in |
Gforth. If you do not have an assembler, you can compile machine code |
Gforth. If you do not have an assembler, you can compile machine code |
directly with @code{,} and @code{c,}. |
directly with @code{,} and @code{c,}. |
Line 2108 These words are rarely used. Therefore t
|
Line 2576 These words are rarely used. Therefore t
|
which is usually not loaded (except @code{flush-icache}, which is always |
which is usually not loaded (except @code{flush-icache}, which is always |
present). You can load them with @code{require code.fs}. |
present). You can load them with @code{require code.fs}. |
|
|
|
In the assembly code you will want to refer to the inner interpreter's |
|
registers (e.g., the data stack pointer) and you may want to use other |
|
registers for temporary storage. Unfortunately, the register allocation |
|
is installation-dependent. |
|
|
|
The easiest solution is to use explicit register declarations |
|
(@pxref{Explicit Reg Vars, , Variables in Specified Registers, gcc.info, |
|
GNU C Manual}) for all of the inner interpreter's registers: You have to |
|
compile Gforth with @code{-DFORCE_REG} (configure option |
|
@code{--enable-force-reg}) and the appropriate declarations must be |
|
present in the @code{machine.h} file (see @code{mips.h} for an example; |
|
you can find a full list of all declarable register symbols with |
|
@code{grep register engine.c}). If you give explicit registers to all |
|
variables that are declared at the beginning of @code{engine()}, you |
|
should be able to use the other caller-saved registers for temporary |
|
storage. Alternatively, you can use the @code{gcc} option |
|
@code{-ffixed-REG} (@pxref{Code Gen Options, , Options for Code |
|
Generation Conventions, gcc.info, GNU C Manual}) to reserve a register |
|
(however, this restriction on register allocation may slow Gforth |
|
significantly). |
|
|
|
If this solution is not viable (e.g., because @code{gcc} does not allow |
|
you to explicitly declare all the registers you need), you have to find |
|
out by looking at the code where the inner interpreter's registers |
|
reside and which registers can be used for temporary storage. You can |
|
get an assembly listing of the engine's code with @code{make engine.s}. |
|
|
|
In any case, it is good practice to abstract your assembly code from the |
|
actual register allocation. E.g., if the data stack pointer resides in |
|
register @code{$17}, create an alias for this register called @code{sp}, |
|
and use that in your assembly code. |
|
|
Another option for implementing normal and defining words efficiently |
Another option for implementing normal and defining words efficiently |
is: adding the wanted functionality to the source of Gforth. For normal |
is: adding the wanted functionality to the source of Gforth. For normal |
words you just have to edit @file{primitives}, defining words (for fast |
words you just have to edit @file{primitives} (@pxref{Automatic |
defined words) probably require changes in @file{engine.c}, |
Generation}), defining words (equivalent to @code{;CODE} words, for fast |
@file{kernal.fs}, @file{prims2x.fs}, and possibly @file{cross.fs}. |
defined words) may require changes in @file{engine.c}, @file{kernal.fs}, |
|
@file{prims2x.fs}, and possibly @file{cross.fs}. |
|
|
|
|
@node Threading Words, , Assembler and Code words, Words |
@node Threading Words, , Assembler and Code words, Words |
Line 2143 doc-douser:
|
Line 2644 doc-douser:
|
doc-dodefer: |
doc-dodefer: |
doc-dofield: |
doc-dofield: |
|
|
Currently there is no installation-independent way for recogizing words |
You can recognize words defined by a @code{CREATE}...@code{DOES>} word |
defined by a @code{CREATE}...@code{DOES>} word; however, once you know |
with @code{>DOES-CODE}. If the word was defined in that way, the value |
that a word is defined by a @code{CREATE}...@code{DOES>} word, you can |
returned is different from 0 and identifies the @code{DOES>} used by the |
use @code{>DOES-CODE}. |
defining word. |
|
|
@node ANS conformance, Model, Words, Top |
@node Tools, ANS conformance, Words, Top |
|
@chapter Tools |
|
|
|
@menu |
|
* ANS Report:: Report the words used, sorted by wordset |
|
@end menu |
|
|
|
See also @ref{Emacs and Gforth}. |
|
|
|
@node ANS Report, , Tools, Tools |
|
@section @file{ans-report.fs}: Report the words used, sorted by wordset |
|
|
|
If you want to label a Forth program as ANS Forth Program, you must |
|
document which wordsets the program uses; for extension wordsets, it is |
|
helpful to list the words the program requires from these wordsets |
|
(because Forth systems are allowed to provide only some words of them). |
|
|
|
The @file{ans-report.fs} tool makes it easy for you to determine which |
|
words from which wordset and which non-ANS words your application |
|
uses. You simply have to include @file{ans-report.fs} before loading the |
|
program you want to check. After loading your program, you can get the |
|
report with @code{print-ans-report}. A typical use is to run this as |
|
batch job like this: |
|
@example |
|
gforth ans-report.fs myprog.fs -e "print-ans-report bye" |
|
@end example |
|
|
|
The output looks like this (for @file{compat/control.fs}): |
|
@example |
|
The program uses the following words |
|
from CORE : |
|
: POSTPONE THEN ; immediate ?dup IF 0= |
|
from BLOCK-EXT : |
|
\ |
|
from FILE : |
|
( |
|
@end example |
|
|
|
@subsection Caveats |
|
|
|
Note that @file{ans-report.fs} just checks which words are used, not whether |
|
they are used in an ANS Forth conforming way! |
|
|
|
Some words are defined in several wordsets in the |
|
standard. @file{ans-report.fs} reports them for only one of the |
|
wordsets, and not necessarily the one you expect. It depends on usage |
|
which wordset is the right one to specify. E.g., if you only use the |
|
compilation semantics of @code{S"}, it is a Core word; if you also use |
|
its interpretation semantics, it is a File word. |
|
|
|
|
|
@node ANS conformance, Model, Tools, Top |
@chapter ANS conformance |
@chapter ANS conformance |
|
|
To the best of our knowledge, Gforth is an |
To the best of our knowledge, Gforth is an |
|
|
ANS Forth System |
ANS Forth System |
@itemize |
@itemize @bullet |
@item providing the Core Extensions word set |
@item providing the Core Extensions word set |
@item providing the Block word set |
@item providing the Block word set |
@item providing the Block Extensions word set |
@item providing the Block Extensions word set |
Line 2173 ANS Forth System
|
Line 2725 ANS Forth System
|
@item providing the Memory-Allocation word set |
@item providing the Memory-Allocation word set |
@item providing the Memory-Allocation Extensions word set (that one's easy) |
@item providing the Memory-Allocation Extensions word set (that one's easy) |
@item providing the Programming-Tools word set |
@item providing the Programming-Tools word set |
@item providing @code{;code}, @code{AHEAD}, @code{ASSEMBLER}, @code{BYE}, @code{CODE}, @code{CS-PICK}, @code{CS-ROLL}, @code{STATE}, @code{[ELSE]}, @code{[IF]}, @code{[THEN]} from the Programming-Tools Extensions word set |
@item providing @code{;CODE}, @code{AHEAD}, @code{ASSEMBLER}, @code{BYE}, @code{CODE}, @code{CS-PICK}, @code{CS-ROLL}, @code{STATE}, @code{[ELSE]}, @code{[IF]}, @code{[THEN]} from the Programming-Tools Extensions word set |
@item providing the Search-Order word set |
@item providing the Search-Order word set |
@item providing the Search-Order Extensions word set |
@item providing the Search-Order Extensions word set |
@item providing the String word set |
@item providing the String word set |
Line 2231 processor-dependent. Gforth's alignment
|
Line 2783 processor-dependent. Gforth's alignment
|
|
|
@item @code{EMIT} and non-graphic characters: |
@item @code{EMIT} and non-graphic characters: |
The character is output using the C library function (actually, macro) |
The character is output using the C library function (actually, macro) |
@code{putchar}. |
@code{putc}. |
|
|
@item character editing of @code{ACCEPT} and @code{EXPECT}: |
@item character editing of @code{ACCEPT} and @code{EXPECT}: |
This is modeled on the GNU readline library (@pxref{Readline |
This is modeled on the GNU readline library (@pxref{Readline |
Line 2251 installation-dependent. Currently a char
|
Line 2803 installation-dependent. Currently a char
|
|
|
@item character-set extensions and matching of names: |
@item character-set extensions and matching of names: |
Any character except the ASCII NUL charcter can be used in a |
Any character except the ASCII NUL charcter can be used in a |
name. Matching is case-insensitive. The matching is performed using the |
name. Matching is case-insensitive (except in @code{TABLE}s. The |
C function @code{strncasecmp}, whose function is probably influenced by |
matching is performed using the C function @code{strncasecmp}, whose |
the locale. E.g., the @code{C} locale does not know about accents and |
function is probably influenced by the locale. E.g., the @code{C} locale |
umlauts, so they are matched case-sensitively in that locale. For |
does not know about accents and umlauts, so they are matched |
portability reasons it is best to write programs such that they work in |
case-sensitively in that locale. For portability reasons it is best to |
the @code{C} locale. Then one can use libraries written by a Polish |
write programs such that they work in the @code{C} locale. Then one can |
programmer (who might use words containing ISO Latin-2 encoded |
use libraries written by a Polish programmer (who might use words |
characters) and by a French programmer (ISO Latin-1) in the same program |
containing ISO Latin-2 encoded characters) and by a French programmer |
(of course, @code{WORDS} will produce funny results for some of the |
(ISO Latin-1) in the same program (of course, @code{WORDS} will produce |
words (which ones, depends on the font you are using)). Also, the locale |
funny results for some of the words (which ones, depends on the font you |
you prefer may not be available in other operating systems. Hopefully, |
are using)). Also, the locale you prefer may not be available in other |
Unicode will solve these problems one day. |
operating systems. Hopefully, Unicode will solve these problems one day. |
|
|
@item conditions under which control characters match a space delimiter: |
@item conditions under which control characters match a space delimiter: |
If @code{WORD} is called with the space character as a delimiter, all |
If @code{WORD} is called with the space character as a delimiter, all |
Line 2295 The error string is stored into the vari
|
Line 2847 The error string is stored into the vari
|
@code{-2 throw} is performed. |
@code{-2 throw} is performed. |
|
|
@item input line terminator: |
@item input line terminator: |
For interactive input, @kbd{C-m} and @kbd{C-j} terminate lines. One of |
For interactive input, @kbd{C-m} (CR) and @kbd{C-j} (LF) terminate |
these characters is typically produced when you type the @kbd{Enter} or |
lines. One of these characters is typically produced when you type the |
@kbd{Return} key. |
@kbd{Enter} or @kbd{Return} key. |
|
|
@item maximum size of a counted string: |
@item maximum size of a counted string: |
@code{s" /counted-string" environment? drop .}. Currently 255 characters |
@code{s" /counted-string" environment? drop .}. Currently 255 characters |
Line 2318 change it from within Gforth. However, t
|
Line 2870 change it from within Gforth. However, t
|
redirected in the command line that starts Gforth. |
redirected in the command line that starts Gforth. |
|
|
@item method of selecting the user output device: |
@item method of selecting the user output device: |
The user output device is the standard output. It cannot be redirected |
@code{EMIT} and @code{TYPE} output to the file-id stored in the value |
from within Gforth, but typically from the command line that starts |
@code{outfile-id} (@code{stdout} by default). Gforth uses buffered |
Gforth. Gforth uses buffered output, so output on a terminal does not |
output, so output on a terminal does not become visible before the next |
become visible before the next newline or buffer overflow. Output on |
newline or buffer overflow. Output on non-terminals is invisible until |
non-terminals is invisible until the buffer overflows. |
the buffer overflows. |
|
|
@item methods of dictionary compilation: |
@item methods of dictionary compilation: |
What are we expected to document here? |
What are we expected to document here? |
Line 2358 string.
|
Line 2910 string.
|
@code{1 chars .}. 1 on all current ports. |
@code{1 chars .}. 1 on all current ports. |
|
|
@item size of the keyboard terminal buffer: |
@item size of the keyboard terminal buffer: |
Varies. You can determine the size at a specific time using @code{lp@ |
Varies. You can determine the size at a specific time using @code{lp@@ |
tib - .}. It is shared with the locals stack and TIBs of files that |
tib - .}. It is shared with the locals stack and TIBs of files that |
include the current file. You can change the amount of space for TIBs |
include the current file. You can change the amount of space for TIBs |
and locals stack at Gforth startup with the command line option |
and locals stack at Gforth startup with the command line option |
Line 2370 shared with @code{WORD}.
|
Line 2922 shared with @code{WORD}.
|
|
|
@item size of the scratch area returned by @code{PAD}: |
@item size of the scratch area returned by @code{PAD}: |
The remainder of dictionary space. You can even use the unused part of |
The remainder of dictionary space. You can even use the unused part of |
the data stack space. The current size can be computed with @code{sp@ |
the data stack space. The current size can be computed with @code{sp@@ |
pad - .}. |
pad - .}. |
|
|
@item system case-sensitivity characteristics: |
@item system case-sensitivity characteristics: |
Dictionary searches are case insensitive. However, as explained above |
Dictionary searches are case insensitive (except in |
under @i{character-set extensions}, the matching for non-ASCII |
@code{TABLE}s). However, as explained above under @i{character-set |
characters is determined by the locale you are using. In the default |
extensions}, the matching for non-ASCII characters is determined by the |
@code{C} locale all non-ASCII characters are matched case-sensitively. |
locale you are using. In the default @code{C} locale all non-ASCII |
|
characters are matched case-sensitively. |
|
|
@item system prompt: |
@item system prompt: |
@code{ ok} in interpret state, @code{ compiled} in compile state. |
@code{ ok} in interpret state, @code{ compiled} in compile state. |
|
|
@item division rounding: |
@item division rounding: |
installation dependent. @code{s" floored" environment? drop .}. We leave |
installation dependent. @code{s" floored" environment? drop .}. We leave |
the choice to gcc (what to use for @code{/}) and to you (whether to use |
the choice to @code{gcc} (what to use for @code{/}) and to you (whether to use |
@code{fm/mod}, @code{sm/rem} or simply @code{/}). |
@code{fm/mod}, @code{sm/rem} or simply @code{/}). |
|
|
@item values of @code{STATE} when true: |
@item values of @code{STATE} when true: |
Line 2394 the choice to gcc (what to use for @code
|
Line 2947 the choice to gcc (what to use for @code
|
On two's complement machines, arithmetic is performed modulo |
On two's complement machines, arithmetic is performed modulo |
2**bits-per-cell for single arithmetic and 4**bits-per-cell for double |
2**bits-per-cell for single arithmetic and 4**bits-per-cell for double |
arithmetic (with appropriate mapping for signed types). Division by zero |
arithmetic (with appropriate mapping for signed types). Division by zero |
typically results in a @code{-55 throw} (floatingpoint unidentified |
typically results in a @code{-55 throw} (Floating-point unidentified |
fault), although a @code{-10 throw} (divide by zero) would be more |
fault), although a @code{-10 throw} (divide by zero) would be more |
appropriate. |
appropriate. |
|
|
Line 2411 No.
|
Line 2964 No.
|
@table @i |
@table @i |
|
|
@item a name is neither a word nor a number: |
@item a name is neither a word nor a number: |
@code{-13 throw} (Undefined word) |
@code{-13 throw} (Undefined word). Actually, @code{-13 bounce}, which |
|
preserves the data and FP stack, so you don't lose more work than |
|
necessary. |
|
|
@item a definition name exceeds the maximum length allowed: |
@item a definition name exceeds the maximum length allowed: |
@code{-19 throw} (Word name too long) |
@code{-19 throw} (Word name too long) |
Line 2428 flow words, and issue a @code{ABORT"} or
|
Line 2983 flow words, and issue a @code{ABORT"} or
|
mismatch). |
mismatch). |
|
|
@item attempting to obtain the execution token of a word with undefined execution semantics: |
@item attempting to obtain the execution token of a word with undefined execution semantics: |
You get an execution token representing the compilation semantics |
@code{-14 throw} (Interpreting a compile-only word). In some cases, you |
instead. |
get an execution token for @code{compile-only-error} (which performs a |
|
@code{-14 throw} when executed). |
|
|
@item dividing by zero: |
@item dividing by zero: |
typically results in a @code{-55 throw} (floating point unidentified |
typically results in a @code{-55 throw} (floating point unidentified |
Line 2450 error appears at a different place when
|
Line 3006 error appears at a different place when
|
|
|
@item interpreting a word with undefined interpretation semantics: |
@item interpreting a word with undefined interpretation semantics: |
For some words, we defined interpretation semantics. For the others: |
For some words, we defined interpretation semantics. For the others: |
@code{-14 throw} (Interpreting a compile-only word). Note that this is |
@code{-14 throw} (Interpreting a compile-only word). |
checked only by the outer (aka text) interpreter; if the word is |
|
@code{execute}d in some other way, it will typically perform it's |
|
compilation semantics even in interpret state. (We could change @code{'} |
|
and relatives not to give the xt of such words, but we think that would |
|
be too restrictive). |
|
|
|
@item modifying the contents of the input buffer or a string literal: |
@item modifying the contents of the input buffer or a string literal: |
These are located in writable memory and can be modified. |
These are located in writable memory and can be modified. |
Line 2482 underflow) is performed. Apart from that
|
Line 3033 underflow) is performed. Apart from that
|
underflows can result in similar behaviour as overflows (of adjacent |
underflows can result in similar behaviour as overflows (of adjacent |
stacks). |
stacks). |
|
|
@item unexepected end of the input buffer, resulting in an attempt to use a zero-length string as a name: |
@item unexpected end of the input buffer, resulting in an attempt to use a zero-length string as a name: |
@code{Create} and its descendants perform a @code{-16 throw} (Attempt to |
@code{Create} and its descendants perform a @code{-16 throw} (Attempt to |
use zero-length string as a name). Words like @code{'} probably will not |
use zero-length string as a name). Words like @code{'} probably will not |
find what they search. Note that it is possible to create zero-length |
find what they search. Note that it is possible to create zero-length |
Line 2492 names with @code{nextname} (should it no
|
Line 3043 names with @code{nextname} (should it no
|
The next invocation of a parsing word returns a string wih length 0. |
The next invocation of a parsing word returns a string wih length 0. |
|
|
@item @code{RECURSE} appears after @code{DOES>}: |
@item @code{RECURSE} appears after @code{DOES>}: |
Compiles a recursive call to the defining word not to the defined word. |
Compiles a recursive call to the defining word, not to the defined word. |
|
|
@item argument input source different than current input source for @code{RESTORE-INPUT}: |
@item argument input source different than current input source for @code{RESTORE-INPUT}: |
!!???If the argument input source is a valid input source then it gets |
@code{-12 THROW}. Note that, once an input file is closed (e.g., because |
restored. Otherwise causes @code{-12 THROW}, which, unless caught, issues |
the end of the file was reached), its source-id may be |
the message "argument type mismatch" and aborts. |
reused. Therefore, restoring an input source specification referencing a |
|
closed file may lead to unpredictable results instead of a @code{-12 |
|
THROW}. |
|
|
|
In the future, Gforth may be able to restore input source specifications |
|
from other than the current input soruce. |
|
|
@item data space containing definitions gets de-allocated: |
@item data space containing definitions gets de-allocated: |
Deallocation with @code{allot} is not checked. This typically resuls in |
Deallocation with @code{allot} is not checked. This typically resuls in |
Line 2524 stack items are loop control parameters
|
Line 3080 stack items are loop control parameters
|
@code{abort" last word was headerless"}. |
@code{abort" last word was headerless"}. |
|
|
@item name not defined by @code{VALUE} used by @code{TO}: |
@item name not defined by @code{VALUE} used by @code{TO}: |
@code{-32 throw} (Invalid name argument) |
@code{-32 throw} (Invalid name argument) (unless name was defined by |
|
@code{CONSTANT}; then it just changes the constant). |
|
|
@item name not found (@code{'}, @code{POSTPONE}, @code{[']}, @code{[COMPILE]}): |
@item name not found (@code{'}, @code{POSTPONE}, @code{[']}, @code{[COMPILE]}): |
@code{-13 throw} (Undefined word) |
@code{-13 throw} (Undefined word) |
Line 2534 Gforth behaves as if they were of the sa
|
Line 3091 Gforth behaves as if they were of the sa
|
the behaviour by interpreting all parameters as, e.g., signed. |
the behaviour by interpreting all parameters as, e.g., signed. |
|
|
@item @code{POSTPONE} or @code{[COMPILE]} applied to @code{TO}: |
@item @code{POSTPONE} or @code{[COMPILE]} applied to @code{TO}: |
Assume @code{: X POSTPONE TO ; IMMEDIATE}. @code{X} is equivalent to |
Assume @code{: X POSTPONE TO ; IMMEDIATE}. @code{X} performs the |
@code{TO}. |
compilation semantics of @code{TO}. |
|
|
@item String longer than a counted string returned by @code{WORD}: |
@item String longer than a counted string returned by @code{WORD}: |
Not checked. The string will be ok, but the count will, of course, |
Not checked. The string will be ok, but the count will, of course, |
Line 2569 Not checked. As usual, you can expect me
|
Line 3126 Not checked. As usual, you can expect me
|
None. |
None. |
|
|
@item operator's terminal facilities available: |
@item operator's terminal facilities available: |
!!?? |
After processing the command line, Gforth goes into interactive mode, |
|
and you can give commands to Gforth interactively. The actual facilities |
|
available depend on how you invoke Gforth. |
|
|
@item program data space available: |
@item program data space available: |
@code{sp@ here - .} gives the space remaining for dictionary and data |
@code{sp@@ here - .} gives the space remaining for dictionary and data |
stack together. |
stack together. |
|
|
@item return stack space available: |
@item return stack space available: |
!!?? |
By default 16 KBytes. The default can be overridden with the @code{-r} |
|
switch (@pxref{Invocation}) when Gforth starts up. |
|
|
@item stack space available: |
@item stack space available: |
@code{sp@ here - .} gives the space remaining for dictionary and data |
@code{sp@@ here - .} gives the space remaining for dictionary and data |
stack together. |
stack together. |
|
|
@item system dictionary space required, in address units: |
@item system dictionary space required, in address units: |
Line 2705 The least significant cell of @var{d} is
|
Line 3265 The least significant cell of @var{d} is
|
The codes -256@minus{}-511 are used for reporting signals (see |
The codes -256@minus{}-511 are used for reporting signals (see |
@file{errore.fs}). The codes -512@minus{}-2047 are used for OS errors |
@file{errore.fs}). The codes -512@minus{}-2047 are used for OS errors |
(for file and memory allocation operations). The mapping from OS error |
(for file and memory allocation operations). The mapping from OS error |
numbers to throw code is -512@minus{}@var{errno}. One side effect of |
numbers to throw code is -512@minus{}@code{errno}. One side effect of |
this mapping is that undefined OS errors produce a message with a |
this mapping is that undefined OS errors produce a message with a |
strange number; e.g., @code{-1000 THROW} results in @code{Unknown error |
strange number; e.g., @code{-1000 THROW} results in @code{Unknown error |
488} on my system. |
488} on my system. |
Line 2822 of open files available. This should not
|
Line 3382 of open files available. This should not
|
@code{/line}. Currently 255. |
@code{/line}. Currently 255. |
|
|
@item methods of mapping block ranges to files: |
@item methods of mapping block ranges to files: |
Currently, the block words automatically access the file |
By default, blocks are accessed in the file @file{blocks.fb} in the |
@file{blocks.fb} in the currend working directory. More sophisticated |
current working directory. The file can be switched with @code{USE}. |
methods could be implemented if there is demand (and a volunteer). |
|
|
|
@item number of string buffers provided by @code{S"}: |
@item number of string buffers provided by @code{S"}: |
1 |
1 |
Line 2897 System dependent; @code{REPRESENT} is im
|
Line 3456 System dependent; @code{REPRESENT} is im
|
function @code{ecvt()} and inherits its behaviour in this respect. |
function @code{ecvt()} and inherits its behaviour in this respect. |
|
|
@item rounding or truncation of floating-point numbers: |
@item rounding or truncation of floating-point numbers: |
What's the question?!! |
System dependent; the rounding behaviour is inherited from the hosting C |
|
compiler. IEEE-FP-based (i.e., most) systems by default round to |
|
nearest, and break ties by rounding to even (i.e., such that the last |
|
bit of the mantissa is 0). |
|
|
@item size of floating-point stack: |
@item size of floating-point stack: |
@code{s" FLOATING-STACK" environment? drop .}. Can be changed at startup |
@code{s" FLOATING-STACK" environment? drop .}. Can be changed at startup |
Line 2917 with the command-line option @code{-f}.
|
Line 3479 with the command-line option @code{-f}.
|
@table @i |
@table @i |
|
|
@item @code{df@@} or @code{df!} used with an address that is not double-float aligned: |
@item @code{df@@} or @code{df!} used with an address that is not double-float aligned: |
System-dependent. Typically results in an alignment fault like other |
System-dependent. Typically results in a @code{-23 THROW} like other |
alignment violations. |
alignment violations. |
|
|
@item @code{f@@} or @code{f!} used with an address that is not float aligned: |
@item @code{f@@} or @code{f!} used with an address that is not float aligned: |
System-dependent. Typically results in an alignment fault like other |
System-dependent. Typically results in a @code{-23 THROW} like other |
alignment violations. |
alignment violations. |
|
|
@item Floating-point result out of range: |
@item Floating-point result out of range: |
Line 3069 intended as throw codes. They typically
|
Line 3631 intended as throw codes. They typically
|
@table @i |
@table @i |
|
|
@item ending sequence for input following @code{;code} and @code{code}: |
@item ending sequence for input following @code{;code} and @code{code}: |
Not implemented (yet). |
@code{end-code} |
|
|
@item manner of processing input following @code{;code} and @code{code}: |
@item manner of processing input following @code{;code} and @code{code}: |
Not implemented (yet). |
The @code{assembler} vocabulary is pushed on the search order stack, and |
|
the input is processed by the text interpreter, (starting) in interpret |
|
state. |
|
|
@item search order capability for @code{EDITOR} and @code{ASSEMBLER}: |
@item search order capability for @code{EDITOR} and @code{ASSEMBLER}: |
Not implemented (yet). If they were implemented, they would use the |
The ANS Forth search order word set. |
search order wordset. |
|
|
|
@item source and format of display by @code{SEE}: |
@item source and format of display by @code{SEE}: |
The source for @code{see} is the intermediate code used by the inner |
The source for @code{see} is the intermediate code used by the inner |
Line 3105 unlucky, this ambiguous condition is not
|
Line 3668 unlucky, this ambiguous condition is not
|
Not implemented (yet). |
Not implemented (yet). |
|
|
@item @var{name} not defined via @code{CREATE}: |
@item @var{name} not defined via @code{CREATE}: |
@code{;code} is not implemented (yet). If it were, it would behave like |
@code{;code} behaves like @code{DOES>} in this respect, i.e., it changes |
@code{DOES>} in this respect, i.e., change the execution semantics of |
the execution semantics of the last defined word no matter how it was |
the last defined word no matter how it was defined. |
defined. |
|
|
@item @code{POSTPONE} applied to @code{[IF]}: |
@item @code{POSTPONE} applied to @code{[IF]}: |
After defining @code{: X POSTPONE [IF] ; IMMEDIATE}. @code{X} is |
After defining @code{: X POSTPONE [IF] ; IMMEDIATE}. @code{X} is |
Line 3157 Not implemented (yet).
|
Line 3720 Not implemented (yet).
|
@table @i |
@table @i |
|
|
@item changing the compilation wordlist (during compilation): |
@item changing the compilation wordlist (during compilation): |
The definition is put into the wordlist that is the compilation wordlist |
The word is entered into the wordlist that was the compilation wordlist |
when @code{REVEAL} is executed (by @code{;}, @code{DOES>}, |
at the start of the definition. Any changes to the name field (e.g., |
@code{RECURSIVE}, etc.). |
@code{immediate}) or the code field (e.g., when executing @code{DOES>}) |
|
are applied to the latest defined word (as reported by @code{last} or |
|
@code{lastxt}), if possible, irrespective of the compilation wordlist. |
|
|
@item search order empty (@code{previous}): |
@item search order empty (@code{previous}): |
@code{abort" Vocstack empty"}. |
@code{abort" Vocstack empty"}. |
Line 3169 when @code{REVEAL} is executed (by @code
|
Line 3734 when @code{REVEAL} is executed (by @code
|
|
|
@end table |
@end table |
|
|
|
@node Model, Integrating Gforth, ANS conformance, Top |
@node Model, Emacs and Gforth, ANS conformance, Top |
|
@chapter Model |
@chapter Model |
|
|
@node Emacs and Gforth, Internals, Model, Top |
This chapter has yet to be written. It will contain information, on |
|
which internal structures you can rely. |
|
|
|
@node Integrating Gforth, Emacs and Gforth, Model, Top |
|
@chapter Integrating Gforth into C programs |
|
|
|
This is not yet implemented. |
|
|
|
Several people like to use Forth as scripting language for applications |
|
that are otherwise written in C, C++, or some other language. |
|
|
|
The Forth system ATLAST provides facilities for embedding it into |
|
applications; unfortunately it has several disadvantages: most |
|
importantly, it is not based on ANS Forth, and it is apparently dead |
|
(i.e., not developed further and not supported). The facilities |
|
provided by Gforth in this area are inspired by ATLASTs facilities, so |
|
making the switch should not be hard. |
|
|
|
We also tried to design the interface such that it can easily be |
|
implemented by other Forth systems, so that we may one day arrive at a |
|
standardized interface. Such a standard interface would allow you to |
|
replace the Forth system without having to rewrite C code. |
|
|
|
You embed the Gforth interpreter by linking with the library |
|
@code{libgforth.a} (give the compiler the option @code{-lgforth}). All |
|
global symbols in this library that belong to the interface, have the |
|
prefix @code{forth_}. (Global symbols that are used internally have the |
|
prefix @code{gforth_}). |
|
|
|
You can include the declarations of Forth types and the functions and |
|
variables of the interface with @code{#include <forth.h>}. |
|
|
|
Types. |
|
|
|
Variables. |
|
|
|
Data and FP Stack pointer. Area sizes. |
|
|
|
functions. |
|
|
|
forth_init(imagefile) |
|
forth_evaluate(string) exceptions? |
|
forth_goto(address) (or forth_execute(xt)?) |
|
forth_continue() (a corountining mechanism) |
|
|
|
Adding primitives. |
|
|
|
No checking. |
|
|
|
Signals? |
|
|
|
Accessing the Stacks |
|
|
|
@node Emacs and Gforth, Internals, Integrating Gforth, Top |
@chapter Emacs and Gforth |
@chapter Emacs and Gforth |
|
|
Gforth comes with @file{gforth.el}, an improved version of |
Gforth comes with @file{gforth.el}, an improved version of |
@file{forth.el} by Goran Rydqvist (icluded in the TILE package). The |
@file{forth.el} by Goran Rydqvist (included in the TILE package). The |
improvements are a better (but still not perfect) handling of |
improvements are a better (but still not perfect) handling of |
indentation. I have also added comment paragraph filling (@kbd{M-q}), |
indentation. I have also added comment paragraph filling (@kbd{M-q}), |
commenting (@kbd{C-x \}) and uncommenting (@kbd{C-u C-x \}) regions and |
commenting (@kbd{C-x \}) and uncommenting (@kbd{C-u C-x \}) regions and |
Line 3199 Also, if you @code{include} @file{etags.
|
Line 3816 Also, if you @code{include} @file{etags.
|
contains the definitions of all words defined afterwards. You can then |
contains the definitions of all words defined afterwards. You can then |
find the source for a word using @kbd{M-.}. Note that emacs can use |
find the source for a word using @kbd{M-.}. Note that emacs can use |
several tags files at the same time (e.g., one for the Gforth sources |
several tags files at the same time (e.g., one for the Gforth sources |
and one for your program). |
and one for your program, @pxref{Select Tags Table,,Selecting a Tags |
|
Table,emacs, Emacs Manual}). The TAGS file for the preloaded words is |
|
@file{$(datadir)/gforth/$(VERSION)/TAGS} (e.g., |
|
@file{/usr/local/share/gforth/0.2.0/TAGS}). |
|
|
To get all these benefits, add the following lines to your @file{.emacs} |
To get all these benefits, add the following lines to your @file{.emacs} |
file: |
file: |
Line 3254 limitations: GNU C, the version of C pro
|
Line 3874 limitations: GNU C, the version of C pro
|
GNU C Manual}). Its labels as values feature (@pxref{Labels as Values, , |
GNU C Manual}). Its labels as values feature (@pxref{Labels as Values, , |
Labels as Values, gcc.info, GNU C Manual}) makes direct and indirect |
Labels as Values, gcc.info, GNU C Manual}) makes direct and indirect |
threading possible, its @code{long long} type (@pxref{Long Long, , |
threading possible, its @code{long long} type (@pxref{Long Long, , |
Double-Word Integers, gcc.info, GNU C Manual}) corresponds to Forths |
Double-Word Integers, gcc.info, GNU C Manual}) corresponds to Forth's |
double numbers. GNU C is available for free on all important (and many |
double numbers@footnote{Unfortunately, long longs are not implemented |
unimportant) UNIX machines, VMS, 80386s running MS-DOS, the Amiga, and |
properly on all machines (e.g., on alpha-osf1, long longs are only 64 |
the Atari ST, so a Forth written in GNU C can run on all these |
bits, the same size as longs (and pointers), but they should be twice as |
machines. |
long according to @ref{Long Long, , Double-Word Integers, gcc.info, GNU |
|
C Manual}). So, we had to implement doubles in C after all. Still, on |
|
most machines we can use long longs and achieve better performance than |
|
with the emulation package.}. GNU C is available for free on all |
|
important (and many unimportant) UNIX machines, VMS, 80386s running |
|
MS-DOS, the Amiga, and the Atari ST, so a Forth written in GNU C can run |
|
on all these machines. |
|
|
Writing in a portable language has the reputation of producing code that |
Writing in a portable language has the reputation of producing code that |
is slower than assembly. For our Forth engine we repeatedly looked at |
is slower than assembly. For our Forth engine we repeatedly looked at |
Line 3497 An important optimization for stack mach
|
Line 4123 An important optimization for stack mach
|
engines, is keeping one or more of the top stack items in |
engines, is keeping one or more of the top stack items in |
registers. If a word has the stack effect @var{in1}...@var{inx} @code{--} |
registers. If a word has the stack effect @var{in1}...@var{inx} @code{--} |
@var{out1}...@var{outy}, keeping the top @var{n} items in registers |
@var{out1}...@var{outy}, keeping the top @var{n} items in registers |
@itemize |
@itemize @bullet |
@item |
@item |
is better than keeping @var{n-1} items, if @var{x>=n} and @var{y>=n}, |
is better than keeping @var{n-1} items, if @var{x>=n} and @var{y>=n}, |
due to fewer loads from and stores to the stack. |
due to fewer loads from and stores to the stack. |
Line 3531 The TOS optimization makes the automatic
|
Line 4157 The TOS optimization makes the automatic
|
bit more complicated. Just replacing all occurrences of @code{sp[0]} by |
bit more complicated. Just replacing all occurrences of @code{sp[0]} by |
@code{TOS} is not sufficient. There are some special cases to |
@code{TOS} is not sufficient. There are some special cases to |
consider: |
consider: |
@itemize |
@itemize @bullet |
@item In the case of @code{dup ( w -- w w )} the generator must not |
@item In the case of @code{dup ( w -- w w )} the generator must not |
eliminate the store to the original location of the item on the stack, |
eliminate the store to the original location of the item on the stack, |
if the TOS optimization is turned on. |
if the TOS optimization is turned on. |
Line 3608 Sieve benchmark on a 486DX2/66 than Gfor
|
Line 4234 Sieve benchmark on a 486DX2/66 than Gfor
|
|
|
However, this potential advantage of assembly language implementations |
However, this potential advantage of assembly language implementations |
is not necessarily realized in complete Forth systems: We compared |
is not necessarily realized in complete Forth systems: We compared |
Gforth (compiled with @code{gcc-2.6.3} and @code{-DFORCE_REG}) with |
Gforth (direct threaded, compiled with @code{gcc-2.6.3} and |
Win32Forth 1.2093 and LMI's NT Forth (Beta, May 1994), two systems |
@code{-DFORCE_REG}) with Win32Forth 1.2093, LMI's NT Forth (Beta, May |
written in assembly, and with two systems written in C: PFE-0.9.11 |
1994) and Eforth (with and without peephole (aka pinhole) optimization |
(compiled with @code{gcc-2.6.3} with the default configuration for |
of the threaded code); all these systems were written in assembly |
Linux: @code{-O2 -fomit-frame-pointer -DUSE_REGS}) and ThisForth Beta |
language. We also compared Gforth with three systems written in C: |
(compiled with gcc-2.6.3 -O3 -fomit-frame-pointer). We benchmarked |
PFE-0.9.14 (compiled with @code{gcc-2.6.3} with the default |
Gforth, PFE and ThisForth on a 486DX2/66 under Linux. Kenneth O'Heskin |
configuration for Linux: @code{-O2 -fomit-frame-pointer -DUSE_REGS |
kindly provided the results for Win32Forth and NT Forth on a 486DX2/66 |
-DUNROLL_NEXT}), ThisForth Beta (compiled with gcc-2.6.3 -O3 |
with similar memory performance under Windows NT. |
-fomit-frame-pointer; ThisForth employs peephole optimization of the |
|
threaded code) and TILE (compiled with @code{make opt}). We benchmarked |
|
Gforth, PFE, ThisForth and TILE on a 486DX2/66 under Linux. Kenneth |
|
O'Heskin kindly provided the results for Win32Forth and NT Forth on a |
|
486DX2/66 with similar memory performance under Windows NT. Marcel |
|
Hendrix ported Eforth to Linux, then extended it to run the benchmarks, |
|
added the peephole optimizer, ran the benchmarks and reported the |
|
results. |
|
|
We used four small benchmarks: the ubiquitous Sieve; bubble-sorting and |
We used four small benchmarks: the ubiquitous Sieve; bubble-sorting and |
matrix multiplication come from the Stanford integer benchmarks and have |
matrix multiplication come from the Stanford integer benchmarks and have |
been translated into Forth by Martin Fraeman; we used the versions |
been translated into Forth by Martin Fraeman; we used the versions |
included in the TILE Forth package; and a recursive Fibonacci number |
included in the TILE Forth package, but with bigger data set sizes; and |
computation for benchmarking calling performance. The following table shows |
a recursive Fibonacci number computation for benchmarking calling |
the time taken for the benchmarks scaled by the time taken by Gforth (in |
performance. The following table shows the time taken for the benchmarks |
other words, it shows the speedup factor that Gforth achieved over the |
scaled by the time taken by Gforth (in other words, it shows the speedup |
other systems). |
factor that Gforth achieved over the other systems). |
|
|
@example |
@example |
relative Win32- NT This- |
relative Win32- NT eforth This- |
time Gforth Forth Forth PFE Forth |
time Gforth Forth Forth eforth +opt PFE Forth TILE |
sieve 1.00 1.30 1.07 1.67 2.98 |
sieve 1.00 1.39 1.14 1.39 0.85 1.58 3.18 8.58 |
bubble 1.00 1.30 1.40 1.66 |
bubble 1.00 1.31 1.41 1.48 0.88 1.50 3.88 |
matmul 1.00 1.40 1.29 2.24 |
matmul 1.00 1.47 1.35 1.46 0.74 1.58 4.09 |
fib 1.00 1.44 1.26 1.82 2.82 |
fib 1.00 1.52 1.34 1.22 0.86 1.74 2.99 4.30 |
@end example |
@end example |
|
|
You may find the good performance of Gforth compared with the systems |
You may find the good performance of Gforth compared with the systems |
Line 3645 method for relocating the Forth image: l
|
Line 4278 method for relocating the Forth image: l
|
the actual addresses at run time, resulting in two address computations |
the actual addresses at run time, resulting in two address computations |
per NEXT (@pxref{System Architecture}). |
per NEXT (@pxref{System Architecture}). |
|
|
The speedup of Gforth over PFE and ThisForth can be easily explained |
Only Eforth with the peephole optimizer performs comparable to |
with the self-imposed restriction to standard C (although the measured |
Gforth. The speedups achieved with peephole optimization of threaded |
implementation of PFE uses a GNU C extension: global register |
code are quite remarkable. Adding a peephole optimizer to Gforth should |
variables), which makes efficient threading impossible. Moreover, |
cause similar speedups. |
current C compilers have a hard time optimizing other aspects of the |
|
ThisForth source. |
The speedup of Gforth over PFE, ThisForth and TILE can be easily |
|
explained with the self-imposed restriction to standard C, which makes |
|
efficient threading impossible (however, the measured implementation of |
|
PFE uses a GNU C extension: @ref{Global Reg Vars, , Defining Global |
|
Register Variables, gcc.info, GNU C Manual}). Moreover, current C |
|
compilers have a hard time optimizing other aspects of the ThisForth |
|
and the TILE source. |
|
|
Note that the performance of Gforth on 386 architecture processors |
Note that the performance of Gforth on 386 architecture processors |
varies widely with the version of @code{gcc} used. E.g., @code{gcc-2.5.8} |
varies widely with the version of @code{gcc} used. E.g., @code{gcc-2.5.8} |
Line 3659 machine registers by itself and would no
|
Line 4298 machine registers by itself and would no
|
register declarations, giving a 1.3 times slower engine (on a 486DX2/66 |
register declarations, giving a 1.3 times slower engine (on a 486DX2/66 |
running the Sieve) than the one measured above. |
running the Sieve) than the one measured above. |
|
|
The numbers in this section have also been published in the paper |
In @cite{Translating Forth to Efficient C} by M. Anton Ertl and Martin |
@cite{Translating Forth to Efficient C} by M. Anton Ertl and Martin |
Maierhofer (presented at EuroForth '95), an indirect threaded version of |
Maierhofer, presented at EuroForth '95. It is available at |
Gforth is compared with Win32Forth, NT Forth, PFE, and ThisForth; that |
|
version of Gforth is 2\%@minus{}8\% slower on a 486 than the version |
|
used here. The paper available at |
@*@file{http://www.complang.tuwien.ac.at/papers/ertl&maierhofer95.ps.gz}; |
@*@file{http://www.complang.tuwien.ac.at/papers/ertl&maierhofer95.ps.gz}; |
it also contains numbers for some native code systems. You can find |
it also contains numbers for some native code systems. You can find |
numbers for Gforth on various machines in @file{Benchres}. |
numbers for Gforth on various machines in @file{Benchres}. |
|
|
@node Bugs, Pedigree, Internals, Top |
@node Bugs, Origin, Internals, Top |
@chapter Bugs |
@chapter Bugs |
|
|
Known bugs are described in the file BUGS in the Gforth distribution. |
Known bugs are described in the file BUGS in the Gforth distribution. |
|
|
If you find a bug, please send a bug report to |
If you find a bug, please send a bug report to |
@code{gforth-bugs@@mips.complang.tuwien.ac.at}. A bug report should |
@code{bug-gforth@@gnu.ai.mit.edu}. A bug report should |
describe the Gforth version used (it is announced at the start of an |
describe the Gforth version used (it is announced at the start of an |
interactive Gforth session), the machine and operating system (on Unix |
interactive Gforth session), the machine and operating system (on Unix |
systems you can use @code{uname -a} to produce this information), the |
systems you can use @code{uname -a} to produce this information), the |
Line 3686 For a thorough guide on reporting bugs r
|
Line 4327 For a thorough guide on reporting bugs r
|
to Report Bugs, gcc.info, GNU C Manual}. |
to Report Bugs, gcc.info, GNU C Manual}. |
|
|
|
|
@node Pedigree, Word Index, Bugs, Top |
@node Origin, Word Index, Bugs, Top |
@chapter Pedigree |
@chapter Authors and Ancestors of Gforth |
|
|
|
@section Authors and Contributors |
|
|
|
The Gforth project was started in mid-1992 by Bernd Paysan and Anton |
|
Ertl. The third major author was Jens Wilke. Lennart Benschop (who was |
|
one of Gforth's first users, in mid-1993) and Stuart Ramsden inspired us |
|
with their continuous feedback. Lennart Benshop contributed |
|
@file{glosgen.fs}, while Stuart Ramsden has been working on automatic |
|
support for calling C libraries. Helpful comments also came from Paul |
|
Kleinrubatscher, Christian Pirker, Dirk Zoller, Marcel Hendrix, John |
|
Wavrik, Barrie Stott and Marc de Groot. |
|
|
|
Gforth also owes a lot to the authors of the tools we used (GCC, CVS, |
|
and autoconf, among others), and to the creators of the Internet: Gforth |
|
was developed across the Internet, and its authors have not met |
|
physically yet. |
|
|
|
@section Pedigree |
|
|
Gforth descends from BigForth (1993) and fig-Forth. Gforth and PFE (by |
Gforth descends from BigForth (1993) and fig-Forth. Gforth and PFE (by |
Dirk Zoller) will cross-fertilize each other. Of course, a significant |
Dirk Zoller) will cross-fertilize each other. Of course, a significant |
Line 3701 VolksForth descends from F83. It was wri
|
Line 4360 VolksForth descends from F83. It was wri
|
Pennemann, Georg Rehfeld and Dietrich Weineck for the C64 (called |
Pennemann, Georg Rehfeld and Dietrich Weineck for the C64 (called |
UltraForth there) in the mid-80s and ported to the Atari ST in 1986. |
UltraForth there) in the mid-80s and ported to the Atari ST in 1986. |
|
|
Laxen and Perry wrote F83 as a model implementation of the |
Henry Laxen and Mike Perry wrote F83 as a model implementation of the |
Forth-83 standard. !! Pedigree? When? |
Forth-83 standard. !! Pedigree? When? |
|
|
A team led by Bill Ragsdale implemented fig-Forth on many processors in |
A team led by Bill Ragsdale implemented fig-Forth on many processors in |
Line 3714 the 1802, and subsequently implemented o
|
Line 4373 the 1802, and subsequently implemented o
|
Z80. |
Z80. |
|
|
All earlier Forth systems were custom-made, usually by Charles Moore, |
All earlier Forth systems were custom-made, usually by Charles Moore, |
who discovered (as he puts it) Forth in the late 60s. |
who discovered (as he puts it) Forth during the late 60s. The first full |
|
Forth existed in 1971. |
|
|
A part of the information in this section comes from @cite{The Evolution |
A part of the information in this section comes from @cite{The Evolution |
of Forth} by Elizabeth D. Rather, Donald R. Colburn and Charles |
of Forth} by Elizabeth D. Rather, Donald R. Colburn and Charles |
Line 3722 H. Moore, presented at the HOPL-II confe
|
Line 4382 H. Moore, presented at the HOPL-II confe
|
Notices 28(3), 1993. You can find more historical and genealogical |
Notices 28(3), 1993. You can find more historical and genealogical |
information about Forth there. |
information about Forth there. |
|
|
@node Word Index, Node Index, Pedigree, Top |
@node Word Index, Node Index, Origin, Top |
@chapter Word Index |
@chapter Word Index |
|
|
This index is as incomplete as the manual. Each word is listed with |
This index is as incomplete as the manual. Each word is listed with |