Re: name for 3 PICK finally?

Op Thu, 06 Mar 2008 12:51:52 -0000 schreef Andrew Haley:

> m_l_g3@[EMAIL PROTECTED]
 wrote:
>> On Mar 5, 11:23 pm, Elizabeth D Rather <erat...@[EMAIL PROTECTED]
> wrote:
>>> m_l...@[EMAIL PROTECTED]
 wrote:
>>> > Some years passed since I have stopped using Forth... But today I
>>> > found that I miss a good name for 3 pick.
>>>
>>> > : DUP 0 PICK ;
>>> > : OVER 1 PICK ;
>>> > : PLUCK 2 PICK ;
>>> > : ??? 3 PICK ;
>>>
>>> > I thought about 3rd and 4th (or third and forth), and even defined
>>> > them,
>>> > but could not make myself use them and finally (yes!)
>>> > refactored the code instead, so that it uses only PLUCK and no 3
PICK.
>>> > (But if there was a name, the 3pick version would be better.)
>>>
>>> > Has anyone finally invented a good name for 3 PICK ?
>>>
>>> Unless it's used a lot, it doesn't need a name.  And if it *is* used a
>>> lot, you need to re-polish your Forth skills.
> 
>> IMO, a separate idea deserves a name, regardless of how often it is
>> used.
> 
> Firstly, 3 PICK isn't a separate idea from 2 PICK: in both cases it's
> a red flag to the reader that you're using the stack as an array.
> Secondly, every reader is instantly going to know what 3 PICK does,
> and giving it a name makes the code harder to read, not easier.  From
> that point of view, the best possible name is 3PICK, since its
> function is obvious.  Finally, if you fix your code you can
> probably make the need for 3PICK go away.
> 
Why would a name like 3PICK be good? If ever (horrors!) you need it, call
it PICK3 or FOURTH. To me 3PICK would pick three items from somewhere deep
into the stack. Mind you, some Forths have 3DUP and 3DROP ;-)


-- 
Coos

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