Expat is the recognized big daddy of XML parsing. It’s a stream-based XML parser written in C and, as a library, is used for XML parsing functions by many languages. Rubyists have tended towards REXML, however, a more flexible (though infinitely slower) parser. Sam Ruby, however, has come up with some techniques to get Ruby’s REXML working with Expat. Read More

After writing a basic routine to print all prime numbers between 1 and 10,000 in Ruby, Pat Eyler found it took almost 3 seconds to complete, and seeked out a way to make it faster. Enter RubyInline (covered previous at RubyInside).. With RubyInline he added a basic C function into the Ruby mix and knocked down the time required to 0.3 seconds.

The code:

require "rubygems"
require "inline"

class Primes
inline do |builder|
builder.c ‘
int prime(int num) {
int x;
for (x = 2; x < (num – 1) ; x++) {
if (num == 2) {
return 1;
}
if (num % x == 0) {
return x;
}
}
return 1;
}’
end
end

p = Primes.new

for num in 2..10_000 do
is_prime = p.prime(num)
if is_prime == 1
puts "#{num} is a prime number"
else
puts "#{num} equals #{is_prime} * #{num/is_prime}"
end
end

Read more.. Read More

_why announces a release of a new UTF-8 library (which adds UTF-8 support to Ruby, without using KCODE) by Nikolai Weibull. _why has also packaged it up (unofficially) into a gem to make it even easier to install (not all of us use git). Here’s some demonstration code: Read More

require ‘encoding/character/utf-8′
str = u"hëllö"
str.length
#=> 5
str.reverse.length
#=> 5
str[/ël/]
#=> "ël"