0)  This is a good idea and has now been implemented
for the next release.  Thanks for the tip.

   7 2&p. b. _1
_3.5 0.5&p.
   ]&.(7 2&p.) 17
17

   7 0&p. b. _1
|domain error
|       7 0&p.b._1

1) There are no plans to do what you suggested,
nor am I convinced by its benefits vs. its cost.



----- Original Message -----
From: David Ward Lambert <[email protected]>
Date: Tuesday, February 9, 2010 13:29
Subject: [Jgeneral] Two requests for j enhancement.
To: General forum <[email protected]>

> Requests for j enhancement based on j64-602, discovered while
> investigating project Euler problem 277.
> 
> 0) Define inverses for linear polynomial evaluation.
> 
>       0 p.^:_1(0)
>    |domain error
>    |   0     p.^:_1(0)
>       0 1 p.^:_1(8)
>    |domain error
>    |   0 1     p.^:_1(8)
> 
> 
> 
> 1) Improve error messages.
> 
>    Domain error does not  isolate "@".  The 
> interpreter COULD identify
>    the problem.
> 
>       %&3...@_1 2&p.
>    |domain error
>    |       %&3...@_1 2&p.
> 
>    jforc/parsing_and_execution_ii.htm#_Toc191734586
> 
>         unprocessedWords 
> stackTopFour restOfStack
> 
>         $vcncncv  
>         $vcncnc v 
>         $vcncn cv 
>         $vcnc ncv 
>         $vcn cncv 
>         $vc ncnc v
>         $v cncn cv
>         $ vcnc ncv
>          $vcn cncv conj 
> rule 4, replace for "vcn" "v"  $v cncv
>          $vcn 
> cv   conj rule 4, replace for "vcn" "v"  $v cv
>          
> $vcv      conj rule 4, replace for 
> "vcv" "v"  $v
>          $v
> 
>    Result is a verb.  Consider the data types.
> 
>          $vcn cncv conj 
> rule 4, replace for "vcn" "v"  $v cncv
>             %&3   verb & noun  works
>          $vcn 
> cv   conj rule 4, replace for "vcn" "v"  $v cv
>             anonymousVerb @ noun
>             Domain error, v...@n is illegal.
>             Arguments to atop cause the problem.
> 
> Thanks,
> Dave.
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