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Groups > comp.lang.forth > #18676

Re: >FLOAT and the empty string

From mhx@iae.nl (Marcel Hendrix)
Subject Re: >FLOAT and the empty string
Newsgroups comp.lang.forth
Message-ID <89711692028434@frunobulax.edu> (permalink)
Date 2013-01-11 19:32 +0200
References <kcnl77$r2q$1@dont-email.me>
Organization Wanadoo

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"David N. Williams" <williams@umich.edu> writes Re: >FLOAT and the empty string

> The post raises this question:
>
>Does the standard specification for >FLOAT require that
>
>   s" " >FLOAT
>
>shall return false, instead of true and 0E0?
[..]
>  A string of blanks should be treated as a special case
>  representing zero.

This seems clear enough.

[..]
>But I don't see how a string of blanks can be empty!  Maybe it
>would be a good idea to specify that the empty string should be
>treated as a special case of a string of blanks.  But if so,
>shouldn't that be made explicit?

> What do people think?

The question seems to be if S" " is formally inside the set 
of "string of blanks." As all Forths certainly think that S"  " 
is a string of one blank, and consider S" " a string, why 
shouldn't S" " not be string of zero blanks (or any other 
character). I don't know if it is possible to prove it, but 
for me the rule of least surprises says it is certainly not
OK say that is NOT a string of blanks. If you take away 1 Euro
from a 1 Euro pile of money, the result is 0 Euros, not 
0 anything.

-- ---------
iForth version 4.0.929, generated 23:21:08, January 7, 2013.
x86_64 binary, native floating-point, extended precision.
Copyright 1996 - 2013 Marcel Hendrix.

FORTH> s" " >FLOAT .s
  Data: -1 ---
System: ---
 Float: 0.0000000000000000000 --- ok
[1]{1}FORTH>
-- ----------

-marcel

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Thread

>FLOAT and the empty string "David N. Williams" <williams@umich.edu> - 2013-01-10 19:09 -0500
  Re: >FLOAT and the empty string "Ed" <invalid@nospam.com> - 2013-01-11 13:32 +1100
  Re: >FLOAT and the empty string anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2013-01-11 11:11 +0000
    Re: >FLOAT and the empty string "Ed" <invalid@nospam.com> - 2013-01-11 23:10 +1100
      Re: >FLOAT and the empty string anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2013-01-23 16:21 +0000
        Re: >FLOAT and the empty string "Ed" <invalid@nospam.com> - 2013-01-25 13:35 +1100
          Re: >FLOAT and the empty string "Elizabeth D. Rather" <erather@forth.com> - 2013-01-25 21:33 +1300
            Re: >FLOAT and the empty string "Elizabeth D. Rather" <erather@forth.com> - 2013-01-25 21:41 +1300
            Re: >FLOAT and the empty string "Ed" <invalid@nospam.com> - 2013-01-28 22:39 +1100
              Re: >FLOAT and the empty string "Elizabeth D. Rather" <erather@forth.com> - 2013-01-28 10:36 -1000
                Re: >FLOAT and the empty string "Ed" <invalid@nospam.com> - 2013-01-29 11:11 +1100
                Re: >FLOAT and the empty string Andrew Haley <andrew29@littlepinkcloud.invalid> - 2013-01-29 03:19 -0600
                Re: >FLOAT and the empty string "Ed" <invalid@nospam.com> - 2013-01-30 11:03 +1100
  Re: >FLOAT and the empty string Andrew Haley <andrew29@littlepinkcloud.invalid> - 2013-01-11 05:39 -0600
    Re: >FLOAT and the empty string anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2013-01-23 16:31 +0000
      Re: >FLOAT and the empty string Andrew Haley <andrew29@littlepinkcloud.invalid> - 2013-01-23 10:44 -0600
        Re: >FLOAT and the empty string anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2013-01-23 17:21 +0000
          Re: >FLOAT and the empty string Andrew Haley <andrew29@littlepinkcloud.invalid> - 2013-01-23 11:50 -0600
            Re: >FLOAT and the empty string anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2013-01-24 13:09 +0000
              Re: >FLOAT and the empty string Andrew Haley <andrew29@littlepinkcloud.invalid> - 2013-01-24 09:22 -0600
                Re: >FLOAT and the empty string anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2013-01-24 16:16 +0000
          Re: >FLOAT and the empty string albert@spenarnc.xs4all.nl (Albert van der Horst) - 2013-01-24 03:45 +0000
            Re: >FLOAT and the empty string anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2013-01-24 12:56 +0000
        Re: >FLOAT and the empty string Alex McDonald <blog@rivadpm.com> - 2013-01-23 16:45 -0800
          Re: >FLOAT and the empty string Andrew Haley <andrew29@littlepinkcloud.invalid> - 2013-01-24 03:43 -0600
            Re: >FLOAT and the empty string Bernd Paysan <bernd.paysan@gmx.de> - 2013-01-24 16:59 +0100
  Re: >FLOAT and the empty string mhx@iae.nl (Marcel Hendrix) - 2013-01-11 19:32 +0200
    Re: >FLOAT and the empty string "David N. Williams" <williams@umich.edu> - 2013-01-20 10:30 -0500
      Re: >FLOAT and the empty string anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2013-01-21 16:51 +0000
      Re: >FLOAT and the empty string "Ed" <invalid@nospam.com> - 2013-01-23 11:42 +1100
        Re: >FLOAT and the empty string Mark Wills <forthfreak@gmail.com> - 2013-01-23 02:38 -0800
          Re: >FLOAT and the empty string anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2013-01-23 15:14 +0000
          Re: >FLOAT and the empty string "Ed" <invalid@nospam.com> - 2013-01-25 14:11 +1100
            Re: >FLOAT and the empty string Mark Wills <forthfreak@gmail.com> - 2013-01-24 23:33 -0800
              Re: >FLOAT and the empty string Andrew Haley <andrew29@littlepinkcloud.invalid> - 2013-01-25 02:52 -0600
              Re: >FLOAT and the empty string "Ed" <invalid@nospam.com> - 2013-01-28 22:53 +1100

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