OpenEuphoria

Re: [poll] all element reference

• Posted by CChris <christian.cuvier at ag?ic?lture.gouv.fr> Aug 22, 2007
• 482 views

Salix wrote:
> 
> Juergen Luethje wrote:
> >  
> > <<a
> > href="http://www.openeuphoria.org/cgi-bin/esearch.exu?fromMonth=9&fromYear=9&toMonth=9&toYear=9&postedBy=Derek+Parnell&keywords=getColumn">http://www.openeuphoria.org/cgi-bin/esearch.exu?fromMonth=9&fromYear=9&toMonth=9&toYear=9&postedBy=Derek+Parnell&keywords=getColumn</a>>
> > 
> 
> If you suggest me to write a function for it then I should 
> agree that it's not a demanding work. On the other hand 
> [*] seems to be more flexibe and handy. Just try to compare 
> the number of characters hit for the example below. 
> 
> But I think the Patrick Barnes email in the same discussion 
> should make me thinking. My justification for this feature 
> was a custom find() situation that I meet regularly. But due 
> to the memory requirement [*] might not be efficient at all. 
> 
> }}}
<eucode>
> -- some more example
> constant x={
> 	{"John",1,74},
> 	{"Mary",5},
> 	{"Andy",2,68},
> 	{"Suse",7,62},
> 	{"Jack",5,84}}
> 
> -- following line would print {1,5,2,7,5}
> ? x[*][2]
> 
> -- following line would print "oanua"
> ? x[*][1][2]
> 
> -- following line would print {'J',1,74}
> ? x[1][*][1]
> </eucode>
{{{

> 
> Cheers,
> 
> Salix

That's the main issue. For it to work right, we'd need to have a "table" native
type to denote a set of columns, each of which with its type. It would be
organised in memory so that [] or [*] could be done more efficiently than by
writing the getColumn() function.

btw, thee way out I use more or less often is to organise tables by field, not
by record. This means having one sequence per field, and recors are of the form
{field_1[i];field_2[i],...}. According to whether you need to access the table
one record or one field at a time, this may be a more efficient alternate
strategy.

CChris