1. Possible idea for a new built-in in Eu 2.4
Hi the list!
I often wind up with having to search for a key at a fixed place in a
sequence of sequences. The following obviously does the job:
<code>
function ffind(object key,integer field,sequence target)
--scans the field-th elements of target for key
--returns index of first record with matching entry or 0 if none found
for i=1 to length(target) do
if target[i][field]=key then return i end if
end for
--not found in this "column"
return 0
end function
</code>
But it may be slow if target is large enough, and I suspect that,
internally, there could be a way to do something like
<notional code>
function ffind(object key,integer field,sequence target)
--same purpose, args and returns as above
return find(key,target[..][field])
end function
</notional code>
Would the built-in be significantly faster? And is there a chance that
it appears in Eu 2.4?
CChris
2. Re: Possible idea for a new built-in in Eu 2.4
----- Original Message -----
From: <Christian.CUVIER at agriculture.gouv.fr>
To: "EUforum" <EUforum at topica.com>
Subject: Possible idea for a new built-in in Eu 2.4
>
> Hi the list!
> I often wind up with having to search for a key at a fixed place in a
> sequence of sequences. The following obviously does the job:
>
> <code>
> function ffind(object key,integer field,sequence target)
> --scans the field-th elements of target for key
> --returns index of first record with matching entry or 0 if none found
> for i=1 to length(target) do
> if target[i][field]=key then return i end if
> end for
> --not found in this "column"
> return 0
> end function
> </code>
What happens when key is a sequence? The above function looks to work best
for atoms,. Try it this way
-------------------------------------------
function ffind(object key,integer field,sequence target)
-------------------------------------------
for n = 1 to length(target) by 1 do
if not compare(target[n][field],key) then
return n
end if
end for
return 0
end function
>
> But it may be slow if target is large enough, and I suspect that,
> internally, there could be a way to do something like
>
> <notional code>
> function ffind(object key,integer field,sequence target)
> --same purpose, args and returns as above
> return find(key,target[..][field])
> end function
> </notional code>
Yes, i think if there was an internal way of doing that it would be
helpful....however there is none that i know of. It all boils down to
looping through the sequence, sorry
Jordah
>
> Would the built-in be significantly faster? And is there a chance that
> it appears in Eu 2.4?
>
> CChris
>
>
>
> TOPICA - Start your own email discussion group. FREE!
>
---
3. Re: Possible idea for a new built-in in Eu 2.4
Again, another idea that looks nice for OpenEu.
Snidely hinting,
jbrown
On Wed, Feb 05, 2003 at 07:30:50PM -0000, jordah at btopenworld.com wrote:
>
>
> ----- Original Message -----
> From: <Christian.CUVIER at agriculture.gouv.fr>
> To: "EUforum" <EUforum at topica.com>
> Sent: Wednesday, February 05, 2003 12:02 PM
> Subject: Possible idea for a new built-in in Eu 2.4
>
>
> > Hi the list!
> > I often wind up with having to search for a key at a fixed place in a
> > sequence of sequences. The following obviously does the job:
> >
> > <code>
> > function ffind(object key,integer field,sequence target)
> > --scans the field-th elements of target for key
> > --returns index of first record with matching entry or 0 if none found
> > for i=1 to length(target) do
> > if target[i][field]=key then return i end if
> > end for
> > --not found in this "column"
> > return 0
> > end function
> > </code>
>
> What happens when key is a sequence? The above function looks to work best
> for atoms,. Try it this way
>
> -------------------------------------------
> function ffind(object key,integer field,sequence target)
> -------------------------------------------
> for n = 1 to length(target) by 1 do
> if not compare(target[n][field],key) then
> return n
> end if
> end for
> return 0
> end function
>
> >
> > But it may be slow if target is large enough, and I suspect that,
> > internally, there could be a way to do something like
> >
> > <notional code>
> > function ffind(object key,integer field,sequence target)
> > --same purpose, args and returns as above
> > return find(key,target[..][field])
> > end function
> > </notional code>
>
> Yes, i think if there was an internal way of doing that it would be
> helpful....however there is none that i know of. It all boils down to
> looping through the sequence, sorry
>
> Jordah
> >
> > Would the built-in be significantly faster? And is there a chance that
> > it appears in Eu 2.4?
> >
> > CChris
> >
> >
> > TOPICA - Start your own email discussion group. FREE!
> >
>
> ---
>
>
>
> TOPICA - Start your own email discussion group. FREE!
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4. Re: Possible idea for a new built-in in Eu 2.4
> ----- Original Message -----
> From: <Christian.CUVIER at agriculture.gouv.fr>
> To: "EUforum" <EUforum at topica.com>
> Sent: Wednesday, February 05, 2003 12:02 PM
> Subject: Possible idea for a new built-in in Eu 2.4
>
> >
> > Hi the list!
> > I often wind up with having to search for a key at a fixed place in a
> > sequence of sequences. The following obviously does the job:
> >
> > <code>
> > function ffind(object key,integer field,sequence target)
> > --scans the field-th elements of target for key
> > --returns index of first record with matching entry or 0 if none found
> > for i=1 to length(target) do
> > if target[i][field]=key then return i end if
> > end for
> > --not found in this "column"
> > return 0
> > end function
> > </code>
>
> What happens when key is a sequence? The above function looks to work best
> for atoms,. Try it this way
>
> -------------------------------------------
> function ffind(object key,integer field,sequence target)
> -------------------------------------------
> for n = 1 to length(target) by 1 do
> if not compare(target[n][field],key) then
> return n
> end if
> end for
> return 0
> end function
Yep, thanks. I didn't have to look for sequences when I devised this,
but you're right.Perhaps I'd prefer "if equal(key,target[n][field]"
rather.
> >
> > But it may be slow if target is large enough, and I suspect that,
> > internally, there could be a way to do something like
> >
> > <notional code>
> > function ffind(object key,integer field,sequence target)
> > --same purpose, args and returns as above
> > return find(key,target[..][field])
> > end function
> > </notional code>
>
> Yes, i think if there was an internal way of doing that it would be
> helpful....however there is none that i know of. It all boils down to
> looping through the sequence, sorry
>
> Jordah
That's the point. If hopping from target[n][field] to
target[n+1][field] internally amounts to computing the latter straight
away, the built-in is of no use, since it doesn't make anything real
faster.
> >
> > Would the built-in be significantly faster? And is there a chance that
> > it appears in Eu 2.4?
> >
> > CChris
CChris
5. Re: Possible idea for a new built-in in Eu 2.4
----- Original Message -----
From: <Christian.CUVIER at agriculture.gouv.fr>
To: "EUforum" <EUforum at topica.com>
Subject: Re: Possible idea for a new built-in in Eu 2.4
>
>
> > ----- Original Message -----
> > From: <Christian.CUVIER at agriculture.gouv.fr>
> > To: "EUforum" <EUforum at topica.com>
> > Sent: Wednesday, February 05, 2003 12:02 PM
> > Subject: Possible idea for a new built-in in Eu 2.4
> >
> > >
> > > Hi the list!
> > > I often wind up with having to search for a key at a fixed place in a
> > > sequence of sequences. The following obviously does the job:
> > >
> > > <code>
> > > function ffind(object key,integer field,sequence target)
> > > --scans the field-th elements of target for key
> > > --returns index of first record with matching entry or 0 if none found
> > > for i=1 to length(target) do
> > > if target[i][field]=key then return i end if
> > > end for
> > > --not found in this "column"
> > > return 0
> > > end function
> > > </code>
> >
> > What happens when key is a sequence? The above function looks to work
best
> > for atoms,. Try it this way
> >
> > -------------------------------------------
> > function ffind(object key,integer field,sequence target)
> > -------------------------------------------
> > for n = 1 to length(target) by 1 do
> > if not compare(target[n][field],key) then
> > return n
> > end if
> > end for
> > return 0
> > end function
>
> Yep, thanks. I didn't have to look for sequences when I devised this,
> but you're right.Perhaps I'd prefer "if equal(key,target[n][field]"
> rather.
Sorry but equal is not as fast as comapre besides....before equal was
introduces IIRC this is the equal i used to use...equal simply calls
compare()
function equal(object a,object b)
return not compare(a,b)
end function
function equal(object a,object b)
return (compare(a,b)=0)
end function
I won't deviate the main purpose of the thread u started.....Yes EU 2.4
should have that ability but i don't think it would be far faster. Besides,
I don't think it can make it to top 10 of Rob's Todo's.
Don't get me wrong, i really find that helpful. Its just that i'm
speaking from my experience and knowledge of RDS
Jordah
>
> > >
> > > But it may be slow if target is large enough, and I suspect that,
> > > internally, there could be a way to do something like
> > >
> > > <notional code>
> > > function ffind(object key,integer field,sequence target)
> > > --same purpose, args and returns as above
> > > return find(key,target[..][field])
> > > end function
> > > </notional code>
> >
> > Yes, i think if there was an internal way of doing that it would be
> > helpful....however there is none that i know of. It all boils down to
> > looping through the sequence, sorry
> >
> > Jordah
>
> That's the point. If hopping from target[n][field] to
> target[n+1][field] internally amounts to computing the latter straight
> away, the built-in is of no use, since it doesn't make anything real
> faster.
True, i feel u
>
> > >
> > > Would the built-in be significantly faster? And is there a chance that
> > > it appears in Eu 2.4?
> > >
> > > CChris
>
> CChris
>
Jordah
>
>
> TOPICA - Start your own email discussion group. FREE!
>
