The difference with the fcase. example at 
http://www.jsoftware.com/help/dictionary/csel.htm

is the "case 2;3" line below pcase.  where the fcase. example that line is 
"case 3"

fcase triggers "2 conditions", but the 2nd is triggered automatically even 
though the input doesn't match that conditions' test.

pcase.  would require that the input match a subsequent condition to be further 
triggered.

an example of the basic case statement


3 : 'select. y case. 1;2 do. 11 case. 2;3 do. 12 end.' 2
11
3 : 'select. y fcase. 1;2 do. 11 case. 3 do. 12 end.' 2
12

only the first condition gets triggered with case.  with fcase.  the 2nd non 
matching condition gets returned, though first has chance to impose side 
effects.  With pcase. the 2nd condition would get returned only if it also 
matched the input.




----- Original Message -----
From: Henry Rich <[email protected]>
To: [email protected]
Sent: Wednesday, March 1, 2017 10:44 PM
Subject: Re: [Jprogramming] fcase.

?

change your pcase. to fcase.; doesn't it do what you say?  Is there 
something your proposed idea would do that the current syntax doesn't do?

Henry Rich

On 3/1/2017 10:14 PM, 'Pascal Jasmin' via Programming wrote:
> Do not see the usefulness of the fcase. option.  see example here:
> http://www.jsoftware.com/help/dictionary/csel.htm
>
>
> I would see a "passthrough case" pcase. usefulness
>
> f2=: 3 : 0
> t=. ''
> select. y
> case.  1 do. t=.t,'one '
> pcase. 2 do. t=.t,'two '
> case.  2;3 do. t=.t,'three '
> case. 2;3;4 do. t=.t,'four '
> end.
> )
>
> f2 2
> two three
>
> a pcase. statement would not abort search after a match.
> ----------------------------------------------------------------------
> For information about J forums see http://www.jsoftware.com/forums.htm


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