OpenEuphoria

RE: Errors in function trim() (ESL0.01)

• Posted by Cuvier Christian <christian.cuvier at insee.fr> Mar 30, 2006
• 444 views

> 
> Subject: Re: Errors in function trim() (ESL0.01)
> 
> 
> posted by: Evan Marshall <1evan at sbcglobal.net>
> 
> Julio C. Galaret Viera wrote:
> > 
> > Taking into account the failure of ESL in providing a 
> working trim() function
> > (though efforts are very much appreciated) and the many 
> working versions of
> > it supplied in this thread.. wouldn't it be nice to see the 
> trim() function
> > built in version 3.0. This function is HEAVILY used by any 
> programmer in the
> > world (or may be in the whole universe?).. 
> > 
> > JG
> 
> 
> Funny, I don't remember the last time I had to use it.......  
> People always say that I'm in a world of my own.
> 

You are not alone. I don't remember either, but I know it only happened once
and the file is on my HD, so I could tell when was that last time.

By the way, I did not perform any benvhmark, but here is a try:

constant white_spaces=" \t\n\r"

global function trim_chars(sequence string,sequence chars_to_remove)
	integer start,end_
	start=find(string[1],chars_to_remove)>0
	end_=find(string[$],chars_to_remove)>0
	if not (start or end_) then
	    return string		--nothing to trim
	end if
	end_=length(string)-end_
	start+=1
	while start<=end_ and find(string[start],chars_to_remove) do
		start+=1	--traverse string and stops at end_ or first
nontrimmable
	end while
	if start>end_ then
	    return ""	-- string trimmed up empey
	end if
	while find(string[end_],chars_to_remove) do
-- traverse backwards and stop at last non trimmable, which is start at
least				end_-=1	
	end while
	return string[start..end_]
end function

global function trim(sequence string)
-- wrapper using predefined constant, assumed to be the most frequent value
-- for the second argument
	return trim_chars(string,white_spaces)
end function

Anyone cares to benchmark all the variants?
CChris