Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > comp.lang.forth > #29713

Re: Recommendation of a Forth to embed in C

Show key headers only | View raw

On Fri, 18 Apr 2014 09:46:48 -0400, <cslarsen@gmail.com> wrote:

> I was hoping I could get some recommendations on a Forth system that I
> can embed in C.
>
> What I'm currently looking for is
>
> - Able to produce Forth bytecode that can be transmitted over the
> network and executed there

I'm not sure of any that can produce bytecode ...  That would dramatically
limit the number of definable Forth words or dictionary size, although
Forths which use bytecode probably do exist.

As for "can be transmitted over the network", did you mean that the
Forth needs to do that, or that you intend to do that? ...

I suspect there aren't as many Forths available with built in networking.
Some do have it though.

> - Able to embed as an execution engine in C or C++

This most likely means coded in C or C++.  There are numerous Forths
coded in C.  There are many in the Usenet archives (circa 1980s, 1990s) for
various newsgroups not just Forth related, many on the web-based Internet,
many in the various Forth archives, and within many in MUD games.  Even
the Bitcoin client has a limited and specialized Forth interpreter built
into it.

> - Able to have Forth words call C functions (no need for a full-blown
> FFI, if I can modify the source and translate the call to C, that'd be
> fine)

This is probably not generally available feature for Forth, unless it's
coded in C/C++.  Most Forths coded in C are switch() based.

If the Forth is coded in C, then the C code can call C functions when
executing Forth words.  So, you'd just need to pass a name or bytecode
over the network to the Forth interpreter, the interpreter then calls
a low-level Forth word ("primitive") with that name/bytecode, that
primitive executes whatever C code you want.  You could pass and push
C arguments that way too.

> - Preferrably have a small memory footprint

Eliminate the dictionary headers on the server side (execution side).
That saves a little bit of space.  Eliminate the outer/text interpreter.
But, you still need two stacks, the compiled definitions, low-level
words ("primitives"), and inner/address interpreter, etc.

> - It must be open source

Most Forths are without copyright, i.e., Public Domain, or copyright
voluntarily surrendered.  If you meant "open source" as in copyrighted
and licensed, the typical meaning of "open source", then that's far less
common.  If you're combining the code with other copyrighted and licensed
code, it's probably best to use similar/same license too, e.g., don't mix
MIT with GPL, etc.  This prevents a problem known as "license pollution".
Also, you might want to avoid Public Domain in that case since technically
it's not copyrighted and merging in copyrighted code could be a legal
complication.

> What I'd really like to avoid is rolling my own Forth.  I've done that
> before, but right now I need something that is robust.

Bytecode (8-bits) limits you to 256 Forth words.  Interpreted Forths
need about 35 low-level words ("primitives").  So, that leaves you with
221 Forth words that you can define.  Is that too limited for the  
dictionary?

Even if 256 Forth words isn't too limited, why bother with Forth? ...
You only want a measely 256 operations.  You've already stated you're
implementing code in C on the server side.  So, why not implement a
switch() statement in C to decode the bytecodes?  Reiterating, most
Forths coded in C are switch() based.  A switch() in C can support
far more than 256 labels too.  With a switch(), the bytecodes can
represent any function or operation which is codeable in C, not just
simple Forth operations.

> I'm only going to execute some simple IF statements and then
> inspect return values to the C environment from the top of the stack.

With just a few operations it's better to use a switch(), and setup
a data stack as an array.  If your work is that limited, you wouldn't
need an interpreter and return stack.  The switch and stack will suffice.

Also, although some here claim that Forth is safe enough to put on the
Internet.  Be warned that interpreted Forth suffers from many of the
same safety issues as C, such as unchecked pointers, stacked control-flow
which is accessible by the user, unchecked buffer limits, ability to
modify executable code, etc.

Also, if you're still interested in the idea Forth, but you're willing
to consider other interpreted languages, you might try another language,
say BrainFuck.  Yes, Brainfuck is too limited with only eight operations.
*BUT* BF is easily extendable, and some enhanced varieties already exist.
More importantly though, BF works against an array which is fixed in size,
i.e., no unbounded pointers, no user access to interpreter control-flow,  
etc.
Obviously though, it's simplicity may be a drawback, unless you can invest
some time to enhance it, but a few more operations shouldn't take you long.

This website covers many experimental languages:
http://esolangs.org/

E.g., Brainfuck derivatives include pbrain (procedures),
Toadskin (Forth style definitions), etc.

These two show you what other standard languages look like:
http://rosettacode.org
http://www.99-bottles-of-beer.net/


Rod Pemberton

Back to comp.lang.forth | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread

Thread

Recommendation of a Forth to embed in C cslarsen@gmail.com - 2014-04-18 06:46 -0700
  Re: Recommendation of a Forth to embed in C Pablo Hugo Reda <pabloreda@gmail.com> - 2014-04-18 07:13 -0700
  Re: Recommendation of a Forth to embed in C Hans Bezemer <the.beez.speaks@gmail.com> - 2014-04-18 16:41 +0200
  Re: Recommendation of a Forth to embed in C jacko <jackokring@gmail.com> - 2014-04-18 11:31 -0700
  Re: Recommendation of a Forth to embed in C "Rod Pemberton" <dont_use_email@xnothavet.cqm> - 2014-04-19 03:08 -0400
    Re: Recommendation of a Forth to embed in C Andrew Haley <andrew29@littlepinkcloud.invalid> - 2014-04-19 02:59 -0500
      Re: Recommendation of a Forth to embed in C "Rod Pemberton" <dont_use_email@xnothavet.cqm> - 2014-04-19 04:55 -0400
        Re: Recommendation of a Forth to embed in C Andrew Haley <andrew29@littlepinkcloud.invalid> - 2014-04-19 16:15 -0500
          Re: Recommendation of a Forth to embed in C Bernd Paysan <bernd.paysan@gmx.de> - 2014-04-19 23:47 +0200
          Re: Recommendation of a Forth to embed in C "Rod Pemberton" <dont_use_email@xnothavet.cqm> - 2014-04-19 22:12 -0400
            Re: Recommendation of a Forth to embed in C Andrew Haley <andrew29@littlepinkcloud.invalid> - 2014-04-20 02:41 -0500
              Re: Recommendation of a Forth to embed in C "Rod Pemberton" <dont_use_email@xnothavet.cqm> - 2014-04-21 21:16 -0400
                Re: Recommendation of a Forth to embed in C "Alex McDonald" <blog@rivadpm.com> - 2014-04-21 18:37 -0700
                Re: Recommendation of a Forth to embed in C "Rod Pemberton" <dont_use_email@xnothavet.cqm> - 2014-04-22 02:48 -0400
                Re: Recommendation of a Forth to embed in C "Alex McDonald" <blog@rivadpm.com> - 2014-04-22 16:15 -0700
                Re: Recommendation of a Forth to embed in C "Rod Pemberton" <dont_use_email@xnothavet.cqm> - 2014-04-22 20:58 -0400
                Re: Recommendation of a Forth to embed in C "Alex McDonald" <blog@rivadpm.com> - 2014-04-22 23:36 -0700
                Re: Recommendation of a Forth to embed in C "Elizabeth D. Rather" <erather@forth.com> - 2014-04-22 21:38 -1000
                Re: Recommendation of a Forth to embed in C "Alex McDonald" <blog@rivadpm.com> - 2014-04-23 06:14 -0700
                Re: Recommendation of a Forth to embed in C "Rod Pemberton" <dont_use_email@xnothavet.cqm> - 2014-04-23 21:10 -0400
                Re: Recommendation of a Forth to embed in C "Alex McDonald" <blog@rivadpm.com> - 2014-04-24 23:09 -0700
                Re: Recommendation of a Forth to embed in C Mark Wills <markwills1970@gmail.com> - 2014-04-24 00:31 -0700
                Re: Recommendation of a Forth to embed in C rickman <gnuarm@gmail.com> - 2014-04-26 20:17 -0400
                Re: Recommendation of a Forth to embed in C rickman <gnuarm@gmail.com> - 2014-04-26 20:29 -0400
                Re: Recommendation of a Forth to embed in C Andrew Haley <andrew29@littlepinkcloud.invalid> - 2014-04-22 05:07 -0500
                Re: Recommendation of a Forth to embed in C "Rod Pemberton" <dont_use_email@xnothavet.cqm> - 2014-04-22 07:54 -0400
                Re: Recommendation of a Forth to embed in C Mark Wills <markwills1970@gmail.com> - 2014-04-22 05:27 -0700
                Re: Recommendation of a Forth to embed in C Andrew Haley <andrew29@littlepinkcloud.invalid> - 2014-04-22 08:37 -0500
                Re: Recommendation of a Forth to embed in C "Rod Pemberton" <dont_use_email@xnothavet.cqm> - 2014-04-22 21:18 -0400
                Re: Recommendation of a Forth to embed in C Melzzzzz <mel@zzzzz.com> - 2014-04-23 07:26 +0200
                Re: Recommendation of a Forth to embed in C Andrew Haley <andrew29@littlepinkcloud.invalid> - 2014-04-23 08:40 -0500
                Re: Recommendation of a Forth to embed in C rickman <gnuarm@gmail.com> - 2014-04-26 21:52 -0400
                Re: Recommendation of a Forth to embed in C "Rod Pemberton" <dont_use_email@xnothavet.cqm> - 2014-04-27 00:18 -0400
                Re: Recommendation of a Forth to embed in C rickman <gnuarm@gmail.com> - 2014-04-27 01:10 -0400
                Re: Recommendation of a Forth to embed in C "Rod Pemberton" <dont_use_email@xnothavet.cqm> - 2014-04-27 01:28 -0400
                Re: Recommendation of a Forth to embed in C rickman <gnuarm@gmail.com> - 2014-04-27 01:42 -0400
                Re: Recommendation of a Forth to embed in C "Rod Pemberton" <dont_use_email@xnothavet.cqm> - 2014-04-27 02:56 -0400
                Re: Recommendation of a Forth to embed in C rickman <gnuarm@gmail.com> - 2014-04-27 03:09 -0400
                Re: Recommendation of a Forth to embed in C "Rod Pemberton" <dont_use_email@xnothavet.cqm> - 2014-04-27 05:07 -0400
        Re: Recommendation of a Forth to embed in C jkn_gg@nicorp.f9.co.uk - 2014-04-20 14:02 -0700
          Re: Recommendation of a Forth to embed in C albert@spenarnc.xs4all.nl (Albert van der Horst) - 2014-04-21 01:27 +0000
            Re: Recommendation of a Forth to embed in C rickman <gnuarm@gmail.com> - 2014-04-21 14:19 -0400
              Re: Recommendation of a Forth to embed in C Bernd Paysan <bernd.paysan@gmx.de> - 2014-04-21 20:35 +0200
              Re: Recommendation of a Forth to embed in C andraszsoter@gmail.com - 2014-04-21 11:54 -0700
              Re: Recommendation of a Forth to embed in C "Rod Pemberton" <dont_use_email@xnothavet.cqm> - 2014-04-21 20:25 -0400
                Re: Recommendation of a Forth to embed in C "Alex McDonald" <blog@rivadpm.com> - 2014-04-21 18:26 -0700
                Re: Recommendation of a Forth to embed in C "Rod Pemberton" <dont_use_email@xnothavet.cqm> - 2014-04-22 03:29 -0400
                Re: Recommendation of a Forth to embed in C "Alex McDonald" <blog@rivadpm.com> - 2014-04-22 16:19 -0700
                Re: Recommendation of a Forth to embed in C "Rod Pemberton" <dont_use_email@xnothavet.cqm> - 2014-04-22 20:23 -0400
                Re: Recommendation of a Forth to embed in C "Alex McDonald" <blog@rivadpm.com> - 2014-04-22 23:16 -0700
                Re: Recommendation of a Forth to embed in C "Rod Pemberton" <dont_use_email@xnothavet.cqm> - 2014-04-27 01:43 -0400
                Re: Recommendation of a Forth to embed in C "Alex McDonald" <blog@rivadpm.com> - 2014-04-27 11:33 +0100
                Re: Recommendation of a Forth to embed in C "Rod Pemberton" <dont_use_email@xnothavet.cqm> - 2014-04-28 01:02 -0400
                Re: Recommendation of a Forth to embed in C Mark Wills <markwills1970@gmail.com> - 2014-04-28 01:27 -0700
                Re: Recommendation of a Forth to embed in C "Elizabeth D. Rather" <erather@forth.com> - 2014-04-27 22:56 -1000
                Re: Recommendation of a Forth to embed in C "Rod Pemberton" <dont_use_email@xnothavet.cqm> - 2014-04-28 05:42 -0400
                Re: Recommendation of a Forth to embed in C Mark Wills <markwills1970@gmail.com> - 2014-04-28 04:24 -0700
                Re: Recommendation of a Forth to embed in C "Alex McDonald" <blog@rivadpm.com> - 2014-04-28 13:43 +0100
                Re: Recommendation of a Forth to embed in C "Rod Pemberton" <dont_use_email@xnothavet.cqm> - 2014-04-29 08:06 -0400
                Re: Recommendation of a Forth to embed in C "Alex McDonald" <blog@rivadpm.com> - 2014-04-29 19:22 +0100
                Re: Recommendation of a Forth to embed in C David Thompson <dave.thompson2@verizon.net> - 2014-05-25 16:44 -0400
                Re: Recommendation of a Forth to embed in C "Rod Pemberton" <dont_use_email@xnothavet.cqm> - 2014-04-29 07:54 -0400
                Re: Recommendation of a Forth to embed in C Mark Wills <markwills1970@gmail.com> - 2014-04-29 06:06 -0700
                Re: Recommendation of a Forth to embed in C "Alex McDonald" <blog@rivadpm.com> - 2014-04-29 19:07 +0100
                Re: Recommendation of a Forth to embed in C Mark Wills <markwills1970@gmail.com> - 2014-04-28 04:17 -0700
                Re: Recommendation of a Forth to embed in C "Rod Pemberton" <dont_use_email@xnothavet.cqm> - 2014-04-29 08:20 -0400
                Re: Recommendation of a Forth to embed in C Mark Wills <markwills1970@gmail.com> - 2014-04-29 06:09 -0700
          Re: Recommendation of a Forth to embed in C "Rod Pemberton" <dont_use_email@xnothaver.cqm> - 2014-04-21 20:39 -0400
    Re: Recommendation of a Forth to embed in C "Elizabeth D. Rather" <erather@forth.com> - 2014-04-18 22:24 -1000
      Re: Recommendation of a Forth to embed in C "Rod Pemberton" <dont_use_email@xnothavet.cqm> - 2014-04-19 05:02 -0400
  Re: Recommendation of a Forth to embed in C Paul Rubin <no.email@nospam.invalid> - 2014-04-19 01:43 -0700
  Re: Recommendation of a Forth to embed in C andraszsoter@gmail.com - 2014-04-21 09:30 -0700
  Re: Recommendation of a Forth to embed in C "VisualForth.com" <babruehl@gmail.com> - 2014-05-25 15:31 -0700
    Re: Recommendation of a Forth to embed in C "Elizabeth D. Rather" <erather@forth.com> - 2014-05-25 16:54 -1000
      Re: Recommendation of a Forth to embed in C Paul Rubin <no.email@nospam.invalid> - 2014-05-25 22:29 -0700
      Re: Recommendation of a Forth to embed in C "VisualForth.com" <babruehl@gmail.com> - 2014-05-26 10:45 -0700
        Re: Recommendation of a Forth to embed in C "Elizabeth D. Rather" <erather@forth.com> - 2014-05-26 09:39 -1000
  Re: Recommendation of a Forth to embed in C Paul Rubin <no.email@nospam.invalid> - 2014-05-25 16:30 -0700

csiph-web