Re: Fixed-point math, ANS, DPL and Win32Forth

Op Fri, 4 Apr 2008 10:45:33 -0700 (PDT) schreef m_l_g3:

> On Apr 3, 3:16 am, George Hubert <georgeahub...@[EMAIL PROTECTED]
> wrote:
>> On Apr 2, 10:44 pm, Alex McDonald <b...@[EMAIL PROTECTED]
> wrote:
>>
>>
>>
>>> On Apr 2, 8:17 am, m_l...@[EMAIL PROTECTED]
 wrote:
>>
>>> > Historically, there has been the variable DPL acquiring its value as
a
>>> > side efect of number conversion.
>>
>>> > For example,
>>
>>> > 1000 \ single, dpl=-1
>>> > 1000. \ double, dpl=0
>>> > 10.00 \ double, dpl=2
>>
>>> > So,
>>> > 1) Why DPL is not in the standard?
>>> > 2) Why DPL is not in Win32Forth?
>>
>>> DP-LOCATION in Version 6 and prior, DPL in the STC version.
>>
>>> --
>>> Regards
>>> Alex McDonald
>>
>> In both cases they're VALUEs rather than a VARIABLE, so code
>> that uses them would be different.
>>
>> George Hubert
> 
> 
> So,
> 
> ' dp-location >body constant DPL
> 
> and a bug fix (for myself, in case I will need the code later)
> 
> 
>: x ( d -- xn ) dpl @[EMAIL PROTECTED]
 1+ if drop then  logscale dpl @[EMAIL PROTECTED]
 0 max - dup abs
> 10^ swap 0< if /
> else * then ;
> 
> The only thing to remember is that constants like 0 and 1 DO NOT
> modify DPL.

I don't define small constants like 0 and 1 ;-)

-- 
Coos

CHForth, 16 bit DOS applications
http://home.hccnet.nl/j.j.haak/forth.html