The relatively poor performance of the ruby program seems to be a result of
looping writing one byte each time. Can ruby interpreter detect and optimize
that loop, or you have to reprogram it for a fair comparison.
William James wrote:
At Mon Sep 24 01:01:12 HKT 2007, Joey K Tuttle wrote:
At 02:53 -0700 2007/09/23, William James wrote:
Bjorn Helgason wrote:
65 66 67{a.
Thanks. I needed this to convert a simple program that
was posted on the Ruby newsgroup to J.
Here's a cleaned up Ruby version.
def scramble( fname )
_fname = fname + ".scrambled"
data = IO.read( fname )
File.open(_fname, "wb"){|ff|
data.each_byte{|c| ff.write((c | 0x80).chr) }
}
end
Here's my J version.
read =: 1!:1
write =: 1!:2
scramble =: verb define
((128 (23 b.) a. i. read <y) { a. ) write <y,'.scrambled'
)
The J program is about 24 times as fast.
The version I wrote in FreeBasic is 9 times as fast as J.
Interesting - what did your FreeBasic version look like?
It's very verbose; the language is designed to be quite
compatible with Microsoft's QBasic, although it has pointers and
C-style macros. The executable is 27,648 bytes. (I hope we won't
be tarred and feathered for being so off topic.)
' The comment character (') is almost invisible.
sub scramble( filename as string )
dim as integer in_handle, out_handle, i, size
dim bytes(1 to 4096) as byte
in_handle = freefile
open filename for binary access read as in_handle
out_handle = freefile
open filename & ".scrambled" for binary access write as out_handle
while not eof( in_handle )
size = seek( in_handle )
get #in_handle, , bytes()
size = seek( in_handle ) - size
for i = 1 to size
bytes(i) = bytes(i) or &h80
next
put #out_handle, , bytes(1), size
wend
close '\ Caution. Closes all open files.
end sub
dim t as double
t = timer
scramble "words"
print timer - t
____________________________________________________________________________________
Be a better Globetrotter. Get better travel answers from someone who knows.
Yahoo! Answers - Check it out.
http://answers.yahoo.com/dir/?link=list&sid=396545469
----------------------------------------------------------------------
For information about J forums see http://www.jsoftware.com/forums.htm
--
regards,
bill
----------------------------------------------------------------------
For information about J forums see http://www.jsoftware.com/forums.htm
