catwell

a = 0
begin
  a += 1
  raise if a < 3
rescue
  puts "rescued"
  retry
ensure
  puts "ensured"
end

catwell

@herberts asked me why I had to leave Télécom Bretagne for Cranfield University to learn about scalability, and I couldn't answer that in 140 chars.

First when I say I left, I just mean I took a double degree during my 3rd year, and I didn't have a choice anyway since school policy makes it mandatory to spend at least a semester abroad. Also, do not misunderstand me: I love the school, I chose to go there instead of "better ranked" schools for a reason. The location is great, and school life too (I couldn't say the same about Cranfield).

As for lessons, I am happy about what I learnt in most department. My problem is with Computer Science & Software Engineering, and it is probably not specific to Télécom Bretagne but the same in most French engineering schools. French engineering students spend their first two years of higher education learning general stuff so most students who enter Télécom Bretagne know nothing at all about CS. The way the curriculum is made, they will have CS classes for at most 3 semes

catwell

Creates a table, fills it with a few values, the current working directory, the current PID and the load average (an array); the load average has a metatable controlling how it's printed.

[spc]lucy:/tmp>gcc -g -shared -fPIC -o silly.so silly.c
[spc]lucy:/tmp>lua
Lua 5.1.4  Copyright (C) 1994-2008 Lua.org, PUC-Rio
require "silly"
x = silly.info()
print(x.cwd,x.pid,x.loadave)
/tmp    22647   (0.06 0.04 0.01)
os.exit()

catwell

require "redis"
R = Redis.new

def watching(*kk)
  5.times do
    R::watch(*kk)
    begin
      r = yield
    rescue Object => e
      R::unwatch

catwell

redis> sismember DSLs Redis
(integer) 1
redis> zrank priorities memory
(integer) 0
redis> hget reasons api
"data structures"
redis> get code
"print STDOUT q; Just another Perl hacker,; unless $spring"
redis> sinter good complexity
(empty list or set)

catwell

Great Software

This is a list of software that I actually like so much that it doesn't make me want to write my own alternative. This is a rare property which usually means that the software doesn't suck too much.

Note: I will not include common Unix tools. Some of them are great too but you probably already knew that.

• dtach
• git
• lua
• msgpack

catwell

# eg.: @slots = Hash[[5,19,20,32,21,28].zip([:new]*6)]
def info_string
  "#{self.to_s.ljust(25)} slots:" + @slots.keys.sort.reduce([]){|a,b|
    if a.empty? || !(a[-1][1]+1 == b)
      a << [b,b]
    else
      a[-1][1] = b
      a
    end
  }.map{|x| (x[0] == x[1]) ? x[1] : "#{x[0]}-#{x[1]}"}.join(",")

catwell

irb(main):095:0> x == y
=> true
irb(main):096:0> cur_users.include?(x)
=> false
irb(main):097:0> cur_users.include?(y)
=> true
irb(main):098:0> cur_users.class
=> Set

catwell

Moodstocks' Ruby Toolkit

"Rising stars" have a (*), "Fading" have a (-)

ActiveRecord Extensions

• annotate-models (-)

Authentication

catwell

require "rubygems"
require "redis"

def time(x)
  t0 = Time.now
  yield
  puts "#{x} - #{1000 * (Time.now - t0)}"
end

L = 1.upto(10000.to_i).to_a