Re: CASEs compared

From	rickman <gnuarm@gmail.com>
Newsgroups	comp.lang.forth
Subject	Re: CASEs compared
Date	2017-02-02 21:55 -0500
Organization	A noiseless patient Spider
Message-ID	<o70rb4$mm$1@dont-email.me> (permalink)
References	(6 earlier) <c11c660a-9699-423a-abce-9aaf0ae48b6a@googlegroups.com> <3ba54b8a-380a-4fc5-84d7-80271d7cd313@googlegroups.com> <o6v0nr$1id1$1@gioia.aioe.org> <o70kdn$j50$1@dont-email.me> <d6711691-7387-4307-b9c7-7970c7162585@googlegroups.com>

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On 2/2/2017 8:05 PM, hughaguilar96@gmail.com wrote:
> On Thursday, February 2, 2017 at 5:57:05 PM UTC-7, rickman wrote:
>> On 2/2/2017 5:12 AM, HAA wrote:
>>> hughaguilar96@gmail.com wrote:
>>>> ...
>>>> Since the title of this thread is "CASEs compared," here is a comparison:
>>>>
>>>> : ccc ( n -- )
>>>>     case
>>>>     2 of  1  endof
>>>>     3 of  2  endof
>>>>     5 of  3  endof
>>>>     7 of  4  endof
>>>>    11 of  5  endof
>>>>    13 of  6  endof
>>>>    17 of  7  endof
>>>>    19 of  8  endof
>>>>    23 of  9  endof
>>>>    29 of 10  endof
>>>>     -1  swap endcase ;  ok
>>>>
>>>> 1 ccc . -1  ok
>>>> 2 ccc . 1  ok
>>>> 29 ccc . 10  ok
>>>> 30 ccc . -1  ok
>>>>
>>>> What usually messes me up when using CASE is that the test value is still on the stack
>>>> after the last ENDOF and it has to be left on the stack so ENDCASE can discard it. That
>>>> is why we have a SWAP in there.
>>>
>>> Having the selector left on the stack when all comparisons fail seems natural and
>>> can be useful.  What gets in the way is ENDCASE wanting to DROP it for you.
>>
>> I've thought the same thing.  Would it make sense for the selector to be
>> held on the return stack so that it can be be accessible and out of the
>> way?  Every iteration of "OF" requires an OVER for the comparison, R@
>> isn't really any harder and the ENDCASE still removes it.  In fact,
>> rather than have OF remove the selector with a DROP, it can be left on
>> the return stack until jumping to the ENDCASE where it is removed.  That
>> saves a bit of code.  It would be a change to the standard of course.
>
> Write an RfD for your suggestion to be put in Forth-200x!

I read your Wikipedia talk page entries for the slide rule page.  Funny 
how much that worked out like things do here.  What do you think is the 
common connection?  Does the Forth community control Wikipedia as well?

-- 

Rick C

Thread

CASEs compared "HAA" <someone@microsoft.com> - 2017-01-30 22:34 +1100
  Re: CASEs compared anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2017-01-30 15:56 +0000
    Re: CASEs compared hughaguilar96@gmail.com - 2017-01-30 09:57 -0800
      Re: CASEs compared "HAA" <someone@microsoft.com> - 2017-01-31 14:26 +1100
        Re: CASEs compared hughaguilar96@gmail.com - 2017-01-31 08:12 -0800
          Re: CASEs compared "HAA" <someone@microsoft.com> - 2017-02-01 11:39 +1100
            Re: CASEs compared hughaguilar96@gmail.com - 2017-01-31 22:37 -0800
              Re: CASEs compared hughaguilar96@gmail.com - 2017-02-01 12:26 -0800
                Re: CASEs compared hughaguilar96@gmail.com - 2017-02-01 16:50 -0800
                Re: CASEs compared hughaguilar96@gmail.com - 2017-02-01 18:02 -0800
                Re: CASEs compared "HAA" <someone@microsoft.com> - 2017-02-02 21:12 +1100
                Re: CASEs compared hughaguilar96@gmail.com - 2017-02-02 13:46 -0800
                Re: CASEs compared hughaguilar96@gmail.com - 2017-02-02 17:01 -0800
                Re: CASEs compared "HAA" <someone@microsoft.com> - 2017-02-04 12:43 +1100
                Re: CASEs compared hughaguilar96@gmail.com - 2017-02-03 17:52 -0800
                Re: CASEs compared Alex <alex@rivadpm.com> - 2017-02-04 11:10 +0000
                Re: CASEs compared rickman <gnuarm@gmail.com> - 2017-02-02 19:57 -0500
                Re: CASEs compared hughaguilar96@gmail.com - 2017-02-02 17:05 -0800
                Re: CASEs compared rickman <gnuarm@gmail.com> - 2017-02-02 21:55 -0500
                Re: CASEs compared Mark Wills <markwills1970@gmail.com> - 2017-02-03 02:11 -0800
                Re: CASEs compared hughaguilar96@gmail.com - 2017-02-03 10:52 -0800
                Re: CASEs compared hughaguilar96@gmail.com - 2017-02-03 17:38 -0800
                Re: CASEs compared rickman <gnuarm@gmail.com> - 2017-02-03 22:08 -0500
                Re: CASEs compared hughaguilar96@gmail.com - 2017-02-03 21:40 -0800
                Re: CASEs compared rickman <gnuarm@gmail.com> - 2017-02-04 01:16 -0500
                Re: CASEs compared rickman <gnuarm@gmail.com> - 2017-02-03 14:40 -0500
                Re: CASEs compared hughaguilar96@gmail.com - 2017-02-03 17:47 -0800
                Re: CASEs compared rickman <gnuarm@gmail.com> - 2017-02-03 22:04 -0500
                Re: CASEs compared "HAA" <someone@microsoft.com> - 2017-02-04 12:39 +1100
                Re: CASEs compared rickman <gnuarm@gmail.com> - 2017-02-03 23:32 -0500
                Re: CASEs compared "HAA" <someone@microsoft.com> - 2017-02-04 22:50 +1100
                Re: CASEs compared rickman <gnuarm@gmail.com> - 2017-02-04 11:07 -0500
                Re: CASEs compared hughaguilar96@gmail.com - 2017-02-04 08:48 -0800
                Re: CASEs compared Mark Wills <markwills1970@gmail.com> - 2017-02-04 10:01 -0800
                Re: CASEs compared rickman <gnuarm@gmail.com> - 2017-02-04 16:43 -0500
                Re: CASEs compared hughaguilar96@gmail.com - 2017-02-04 18:53 -0800
                Re: CASEs compared "HAA" <someone@microsoft.com> - 2017-02-05 19:12 +1100
    Re: CASEs compared "HAA" <someone@microsoft.com> - 2017-01-31 14:25 +1100
  Re: CASEs compared Elliott Chapin <elliott.chapin@gmail.com> - 2017-02-05 08:25 -0800
    Re: CASEs compared Coos Haak <htrofhc@gmail.com> - 2017-02-06 00:42 +0100
  Re: CASEs compared jacko <jackokring@gmail.com> - 2017-02-16 17:46 -0800
    Re: CASEs compared hughaguilar96@gmail.com - 2017-02-17 09:09 -0800

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