OpenEuphoria

Re: Discuss changing the behaviour of append()

• Posted by petelomax Jun 21, 2014
• 4099 views

FYI (this does not really add anything to the subject being discussed), this is how I would code that (if I had to use recursion):

sequence s = {1,2,3,4,5,6,7,8,9,10}  
  
function isEven(atom x)  
    --common utility function  
    return remainder( x,2 ) = 0  
end function  
  
function extractEvens(sequence source, integer done=0, sequence thusfar={})  
    done += 1 
    if done>length(source) then return thusfar end if 
    atom thisone = source[done] 
    if isEven(thisone) then 
        thusfar = append(thusfar,thisone) 
    end if  
    return extractEvens(source, done, thusfar) 
end function   
 
? extractEvens(s)