OpenEuphoria

Re: Best way to find records in sequences?

• Posted by Pete Lomax <petelomax at blueyonder.co.uk> Jul 07, 2006
• 654 views

On Fri, 07 Jul 2006 04:04:57 -0700, ZNorQ <guest at RapidEuphoria.com>
wrote:

> MyErrors = {
>  {"SYN_SE", "Syntax error"                },
>   "ARY_OB", "Out of range"                },
>   "MEM_OO", "Out of memory"               }, 
>   "MEM_LD", "Memory leak detected"        }, 
>   "TOB_TM", "Too much tobacco in keyboard"}}
Umm, if you are going to code "SYN_SE" then you may as well code
"Syntax error"...  
>  MyErrIdx = {"SYN_SE", "ARY_OB", "MEM_OO", "MEM_LD", "TOB_TM"}.
>
>This would ofcourse have to correspond to the same record id as in MyErrors.
...and that would be almost as fiddly/error-prone to keep in line with
the error text set as using literal integers would.

This is what I usually do:

sequence Emsgs
	  Emsgs={}
integer Eused
	Eused = 0
function emsg(sequence txt)
	Eused+=1
	if Eused>length(Emsgs) then
		Emsgs&=repeat(0,32)
	end if
	Emsgs[Eused]=txt
	return Eused
end function

global constant
E_se = emsg("Syntax error"),
E_oor = emsg("Out of range"),
E_oom = emsg("Out of memory"),
E_mld = emsg("Memory leak detected"), 
E_tmkik = emsg("Too much tobacco in keyboard")

global function getEmsg(integer i)
	return Emsgs[i]
end function

You have to choose a prefix which you don't think will clash with
anything else, eg "E_", "EM_", "EI", etc. and/or use global constants
as per the strings you used, ie SYN_SE etc. While (lots of) global
variables is generally considered a bad thing, constants are not;
it is actually worse to make Emsgs global, since a hidden line such as
Emsgs=prepend(Emsgs,"I am a bug") could cause serious confusion.
Even cryptic names such as the above make code easier to read and
maintain than using literal integers, w/o performance loss.
The initialisation overhead is pretty minimal.

Actually, I tend to go one step further and use e01se, e02oor, as a
kind of second-level redundancy check; if I want a sorted list of
error messages I block copy and paste/sort into the documentation.
)

HTH,
Pete