I have my nitpicker hat on today: They are not equivalent
because the former has unbounded rank whereas the latter
has rank 0. This makes a difference in tindexof2:
> tindexof2=: ([,&.>]) tindexof {:@$&.>@([,&.>]) {."1&.>]
wherein you either have to say ,&.>"_ or use @:
----- Original Message -----
From: "R.E. Boss" <[EMAIL PROTECTED]>
Date: Friday, October 12, 2007 6:02
Subject: RE: [Jprogramming] Performance of case-insensitive lookup
To: 'Programming forum' <[email protected]>
>
> [,&.>] is equivalent to ,&.>
>
>
> R.E. Boss
>
>
> > -----Oorspronkelijk bericht-----
> > Van: [EMAIL PROTECTED] [mailto:programming-
> > [EMAIL PROTECTED] Namens Sherlock, Ric
> > Verzonden: vrijdag 12 oktober 2007 14:23
> > Aan: Programming forum
> > Onderwerp: RE: [Jprogramming] Performance of case-insensitive lookup
> >
> > ---Sherlock, Ric wrote
> > > --bill lam wrote:
> > > > Sherlock, Ric wrote:
> > > > > My solutions as follows:
> > > > > textend=: {:@$&.>@[ {."1&.> ]
> > > > > pplinv textend pinv
> > > > > +-------+------+
> > > > > |Joan |Saxon |
> > > > > +-------+------+
> > > > >
> > > > > pplinv tindexof pplinv textend pinv
> > > > > 4
> > > > >
> > > >
> > > > A potential gotcha is that text in pinv is longer than
> pplinv, your
> > > > solution will trim pinv to shorter length but there should
> > > not be any
> > > > match because pinv is longer than pplinv. Of course
> if it is known
> > > > before hand that pinv must be shorter than pplinv, there
> will be no
> > > > problem.
> > >
> > > Very true!
> >
> > I think this solves that problem:
> > tindexof2=: ([,&.>]) tindexof {:@$&.>@([,&.>]) {."1&.>]
> >
> > p3=: 'Josephine';'Saxon'
> > p3inv=: ifa mfv p3
> >
> > Basically I append the names to be looked up to the lookup
> table and
> > then extend the names to be looked up by the widths of the appended
> > lookup table. The lookup is done on the appended table.
> > ppl i. p3
> > 500
> > pplinv tindexof2 p3inv
> > 500
> >
> > Of course if there are more than 1 names to be looked up, the
> result may
> > include indices greater than #ppl, but will still provide the
> correct> answer to the normal "is found" test i.e. the resulting
> index is not
> > less than #ppl
> > (#ppl)> ppl i. p,p3
> > 1 0
> > (ttally pplinv)> pplinv tindexof2 pinv ,each p3inv
> > 1 0
> >
> > Performance is only a bit worse:
> > ts '(tolower each pplinv) tindexof1 (tolower
> each p2inv)'
> > 0.000125434936563 8320
> > ts '(tolower each pplinv) tindexof2 (tolower
> each p2inv)'
> > 0.000133257159779 8320
> >
> > The phrase [,&.>] is used twice so I wonder if it is possible to
> > simplify tindexof2 further?
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