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Groups > comp.lang.forth > #19915

Re: Double integer input

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Anton Ertl wrote:
> And there was a specific occasion that lead to taking out "," in
> Gforth: I wrote a priece of code that used "2,", and it compiled fine
> but did not work.  Eventually I found that Gforth at the time had no
> word "2,", but it had "," as double indicator.  So it saw a double
> literal instead of the word "2,".  With Elisabeth's list, "2-" would
> be another trap.

Yes, but today, 2- is floating point for 2, just like 2+.  We didn't take 
that out, every word that converts to a sensible floating point number with 
>FLOAT is accepted as input.  With our new recognizers, we could implement a 
<number>+ and <number>- recognizer, which would eliminate that trap, and 
just compile the literal + and literal - instead (* and / as well).

Back then, we didn't have a fontlock mode for Emacs (and Emacs didn't have 
fontlock at all, and screens didn't have color, at least the ones I had ;-).  
That would probably have made it easier to debug, if it had correctly 
highlighted 2, as number.

Currently, Gforth has dp-char and fp-char, following MPE, which allows us to 
switch to MPE mode, which is ',' for doubles and '.' for float.  I'm not 
sure if this is all rigth.  My suggestion would be a configuration register 
for dp and fp sepearators, which is a 32 bit mask for the characters between 
$20 and $3F.  But all that has the global state disadvantage - you need to 
say which mode you want to be in, when you aren't in standard mode, and when 
your program is a library, you don't want to disturb the users.

You might also have allowed characters and decimal point characters, so e.g. 
123'456'789.123'456 is valid, and only the decimal point itself is treated 
as such.  Makes numbers more readable.

-- 
Bernd Paysan
"If you want it done right, you have to do it yourself"
http://bernd-paysan.de/

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Double integer input Rosangela Medeiros da Silva <rosangelamesil@gmail.com> - 2013-02-13 18:15 -0800
  Re: Double integer input Rosangela Medeiros da Silva <rosangelamesil@gmail.com> - 2013-02-14 02:07 -0800
    Re: Double integer input Coos Haak <chforth@hccnet.nl> - 2013-02-14 16:18 +0100
      Re: Double integer input Coos Haak <chforth@hccnet.nl> - 2013-02-14 16:27 +0100
      Re: Double integer input "A. K." <akk@nospam.org> - 2013-02-14 20:54 +0100
        Re: Double integer input Coos Haak <chforth@hccnet.nl> - 2013-02-14 23:20 +0100
  Re: Double integer input "Ed" <invalid@nospam.com> - 2013-02-22 11:00 +1100
    Re: Double integer input "Elizabeth D. Rather" <erather@forth.com> - 2013-02-21 14:24 -1000
      Re: Double integer input Bernd Paysan <bernd.paysan@gmx.de> - 2013-02-22 01:50 +0100
        Re: Double integer input anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2013-02-22 15:35 +0000
          Re: Double integer input Bernd Paysan <bernd.paysan@gmx.de> - 2013-02-22 18:15 +0100
            Re: Double integer input stephenXXX@mpeforth.com (Stephen Pelc) - 2013-02-22 19:02 +0000
            Re: Double integer input anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2013-02-23 17:27 +0000
              Re: Double integer input Bernd Paysan <bernd.paysan@gmx.de> - 2013-02-24 03:42 +0100
          Re: Double integer input "Elizabeth D. Rather" <erather@forth.com> - 2013-02-22 09:08 -1000
            Re: Double integer input anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2013-02-23 16:15 +0000
              Re: Double integer input stephenXXX@mpeforth.com (Stephen Pelc) - 2013-02-23 17:35 +0000
                Re: Double integer input anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2013-02-25 15:25 +0000
              Re: Double integer input albert@spenarnc.xs4all.nl (Albert van der Horst) - 2013-02-23 19:34 +0000
                Re: Double integer input "Rod Pemberton" <do_not_have@notemailnotz.cnm> - 2013-02-23 18:35 -0500
              Re: Double integer input Andrew Haley <andrew29@littlepinkcloud.invalid> - 2013-02-23 14:58 -0600
                Re: Double integer input Zbiggy <zbigniew2011REMOVE@gmail.REMOVE.com> - 2013-02-23 22:01 +0100
                Re: Double integer input albert@spenarnc.xs4all.nl (Albert van der Horst) - 2013-02-24 04:03 +0000
                Re: Double integer input "Elizabeth D. Rather" <erather@forth.com> - 2013-02-23 18:13 -1000
                Re: Double integer input Zbiggy <zbigniew2011REMOVE@gmail.REMOVE.com> - 2013-02-24 12:01 +0100
                Re: Double integer input anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2013-02-25 18:09 +0000
                Re: Double integer input rickman <gnuarm@gmail.com> - 2013-02-24 15:01 -0500
                Re: Double integer input Coos Haak <chforth@hccnet.nl> - 2013-02-25 01:13 +0100
                Re: Double integer input Mark Wills <markrobertwills@yahoo.co.uk> - 2013-02-24 23:44 -0800
                Re: Double integer input rickman <gnuarm@gmail.com> - 2013-02-27 07:47 -0500
                Re: Double integer input Mark Wills <markrobertwills@yahoo.co.uk> - 2013-02-24 23:42 -0800
                Re: Double integer input Andrew Haley <andrew29@littlepinkcloud.invalid> - 2013-02-25 03:57 -0600
                Re: Double integer input albert@spenarnc.xs4all.nl (Albert van der Horst) - 2013-02-25 14:09 +0000
                Re: Double integer input Bernd Paysan <bernd.paysan@gmx.de> - 2013-02-25 16:45 +0100
                Re: Double integer input Andrew Haley <andrew29@littlepinkcloud.invalid> - 2013-02-25 18:26 -0600
                Re: Double integer input Bernd Paysan <bernd.paysan@gmx.de> - 2013-02-26 02:04 +0100
                Re: Double integer input Andrew Haley <andrew29@littlepinkcloud.invalid> - 2013-02-26 05:10 -0600
                Re: Double integer input Bernd Paysan <bernd.paysan@gmx.de> - 2013-02-26 15:31 +0100
                Re: Double integer input Andrew Haley <andrew29@littlepinkcloud.invalid> - 2013-02-26 10:28 -0600
                Re: Double integer input anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2013-02-25 16:38 +0000
              Re: Double integer input rickman <gnuarm@gmail.com> - 2013-02-24 14:54 -0500
                Re: Double integer input "Elizabeth D. Rather" <erather@forth.com> - 2013-02-24 11:59 -1000
                Re: Double integer input anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2013-02-25 18:11 +0000
                Re: Double integer input rickman <gnuarm@gmail.com> - 2013-02-27 07:58 -0500
                Re: Double integer input anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2013-03-02 17:10 +0000
      Re: Double integer input "Ed" <invalid@nospam.com> - 2013-02-22 13:22 +1100
        Re: Double integer input "Elizabeth D. Rather" <erather@forth.com> - 2013-02-21 16:31 -1000
      Re: Double integer input Alex McDonald <blog@rivadpm.com> - 2013-02-22 04:54 -0800
        Re: Double integer input "WJ" <w_a_x_man@yahoo.com> - 2013-02-24 22:05 +0000
          Re: Double integer input Paul Rubin <no.email@nospam.invalid> - 2013-02-24 15:02 -0800
          Re: Double integer input Brad Eckert <hwfwguy@gmail.com> - 2013-02-25 09:22 -0800
            Re: Double integer input Brad Eckert <hwfwguy@gmail.com> - 2013-02-25 10:21 -0800
          Re: Double integer input Alex McDonald <blog@rivadpm.com> - 2013-02-26 07:47 -0800
        Re: Double integer input "WJ" <w_a_x_man@yahoo.com> - 2013-02-28 06:27 +0000
      Re: Double integer input Paul Rubin <no.email@nospam.invalid> - 2013-02-23 21:34 -0800
        Re: Double integer input "Elizabeth D. Rather" <erather@forth.com> - 2013-02-24 08:16 -1000

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