From: "Iñaki Baz Castillo" <ibc@...>
Date: 2009-04-02T23:13:28+09:00
Subject: Re: String#capitalize more complex

2009/4/2 Iñaki Baz Castillo <ibc@aliax.net>:

> Is there any option even faster? I think it would be faster if I
> operate directly in the original string instead of doing "split" and
> "join" (since these last methods create more strings so allocate
> memory for them and so). I would prefer to do the modification "in
> place".
>
> BTW, could I know how to convert "a" char into "A"? I expected
> something as in c:
>
>  'a' + 1 => 'b'
>  'a' + ¿X? => 'A'


I've done it in two ways:


-----------------------------
require "benchmark"


hname1 =  "record-route"
hname2 =  "record-route"

rt1=0.0
rt2=0.0


### Method 1

1.upto(10) do
	rt1 += Benchmark.realtime { hname1 = hname1.split("-").map {|w|
w.capitalize }.join("-") }
end
puts "hname1 = #{hname1}  (time = #{rt1/10})"


### Method 2

1.upto(10) do
	i=0
	rt2 += Benchmark.realtime do
		hname2.capitalize!.each_byte do |b|
			if b==45 && i<hname2.bytesize-1
				hname2[i+1] = [hname2[i+1].unpack("*c")[0] - 32].pack("*c")
			end
			i+=1
		end
	end
end
puts "hname2 = #{hname2}  (time = #{rt2/10})"
------------------------------

Results:

  hname1 = Record-Route  (time = 8.24928283691406e-06)
  hname2 = Record-Route  (time = 1.05381011962891e-05)


This is: even if method 1 uses split and join (so it generates new
strings and stores them in memory) it's faster than method 2.
Unfortunatelly method 2 also generates strings. I really wonder if
there is a nicer way to do the same in a more fast way.

Thanks.





-- 
Iñaki Baz Castillo
<ibc@aliax.net>