OpenEuphoria

Re: Better Way to Do This

• Posted by euphoric (admin) Aug 06, 2009
• 1124 views

function no_atoms( sequence s ) 
integer i = length(s) 
while(sequence(s[i]) and i > 0 ) do 
  i -= 1 
end while 
if i = 0 then return 1 else return 0 end if 
end function 

Yeah, that's faster all right! Here's the program I used to test the speeds. Bernie, your suggested code was waaaaaay faster than any other. It should definitely replace our std/lib sequence_array()!

include std/console.e 
 
atom t 
 
function no_atoms_1( sequence s ) 
integer i = 1 
	for t=1 to length(s) do 
		if atom(s[t]) then return 0 end if 
	end for 
	return 1 
end function 
 
function no_atoms_bernie_1( sequence s ) 
integer i = length(s) 
	while sequence(s[i]) and i > 0 do 
		i -= 1 
	end while 
	if i=0 then return 1 else return 0 end if 
end function 
 
function no_atoms_bernie_2( sequence s ) 
integer i = length(s) 
	while sequence(s[i]) and i > 0 do 
		i -= 1 
	end while 
	return not i 
end function 
 
function no_atoms_stdlib( object x ) 
    if not sequence(x) then 
        return 0 
    end if 
 
    for i = 1 to length(x) do 
        if not sequence(x[i]) then 
            return 0 
        end if 
    end for 
    return 1 
end function 
 
sequence a 
a = repeat({},500) 
a &= 1 
 
t = time() 
for x=1 to 100000 do 
	no_atoms_1( a ) 
end for 
?time()-t 
 
t = time() 
for x=1 to 100000 do 
	no_atoms_bernie_1( a ) 
end for 
?time()-t 
 
t = time() 
for x=1 to 100000 do 
	no_atoms_bernie_2( a ) 
end for 
?time()-t 
 
for x=1 to 100000 do 
	no_atoms_stdlib( a ) 
end for 
?time()-t 
 
wait_key() 

The no_atoms_bernie_2() was just my testing of the "not" thingie. Didn't help.

I do have a question. When i gets to zero, why doesn't the test for sequence(s[i]) fail? Or is 0 a valid sequence element?!