OpenEuphoria

Re: Append or concatenate to each element in sequence

• Posted by "Christian Cuvier" <Christian.CUVIER at agriculture.gouv.fr> Aug 20, 2004
• 559 views

> Subject: Append or concatenate to each element in sequence
> 
> 
> posted by: Terry Constant <EUforum at terryconstant.com>
> 
> Is there a better/faster way to concatenate or append to each element 
> in a sequence than by using a loop, something like illustrated below?
> 
> 
> }}}
<eucode>
> sequence s1
> 
> global function seqConcat(sequence srcSeq, object toAppend)
>   sequence dstSeq, curElement
> 
>   dstSeq = {}
>   for i = 1 to length(srcSeq) do
>     curElement = srcSeq[i] & toAppend
>     dstSeq = append(dstSeq, curElement)
>   end for
>   return dstSeq
> end function  --seqConcat()
> 
> s1 = seqConcat({"abc","def","ghi"}, '\n')
> </eucode>
{{{

> 
> 
> My main concern is speed since I will be doing such operations
> on some large sequences.
> 
> Terry Constant

Since the length of dstSeq is known, don't waste time with dynamic mallocs. 
And since your function only knows about a local copy of srcSeq, no need ro do 
any alloc for a temp sequence that will get copied on return:

sequence s1

global function seqConcat(sequence srcSeq, object toAppend)
   for i = 1 to length(srcSeq) do
     srcSeq[i] &= toAppend   --so is it to be appended or to concatenated?
   end for
   return srcSeq
end function  --seqConcat()

s1 = seqConcat({"abc","def","ghi"}, '\n')

I didn't benchmark it, but there are so many reasons for this to be faster...

CChris