1.
We ♥ Haskell
------------------
by @heidiHarman & @greenEmilyMay @scrive
Monday, August 15, 2011

2.
We ♥ Haskell
------------------
The story behind SkrivaPå and more about Haskell
Monday, August 15, 2011

3.
@heidiHarman & @greenEmilyMay @scrive @skrivaPa @scrive_UK
Emily Green Heidi Harman
:: JavaDev -> HaskellDev -> _ Kaospilot, Denmark
ServerCode _ Planner, projectmanager =
:: BristolUni -> Maths -> Degree webagencies
:: JQuery -> CSS -> GUICode _ IFL Stockholm School of Economics
:: Bank -> Scrive -> Happy _ Agencies
_ Runalong Startup
_ GeekGirlMeetup
_ London, Scrive
Monday, August 15, 2011

4.
Structure
allows
freedom
Monday, August 15, 2011

5.
Or as Björk would
have put it:
“I tried organizing freedom,
how scandinavian of me”
Monday, August 15, 2011

6.
SkrivaPå aka Scrive
Digital signatures for
contracts etc
Monday, August 15, 2011

7.
@heidiHarman & @greenEmilyMay @scrive @skrivaPa @scrive_UK
Why SkrivaPå?
> Proven business model and product
> A fantastic Team
Monday, August 15, 2011

8.
@heidiHarman & @greenEmilyMay @scrive @skrivaPa @scrive_UK
Why SkrivaPå? Yes, it’s as
simple as that!
> Proven business model and product
> A fantastic Team
Monday, August 15, 2011

9.
@heidiHarman & @greenEmilyMay @scrive @skrivaPa @scrive_UK
Tibetan Patches
3
3 3
1
Monday, August 15, 2011

10.
@heidiHarman & @greenEmilyMay @scrive @skrivaPa @scrive_UK
We Use Haskell
Because the CTO, Gracjan, wanted to.
“Haskell, whatʼs that?”
> Itʼs a strongly typed, lazily evaluated, functional language.
“Haskell, thatʼs a brave choice.”
> Itʼs well-known and loved in academic circles, but a bit unusual of
an unusual choice for building “real stuff”.
Monday, August 15, 2011

11.
@heidiHarman & @greenEmilyMay @scrive @skrivaPa @scrive_UK
Can I Describe What itʼs
Like? Imagine: Variables
canʼt change value.
Once you set the value of a variable you canʼt change it. Ever.
(If you ask me how to keep an incrementing count of user logins, I
shall say “monads”.)
Monday, August 15, 2011

12.
@heidiHarman & @greenEmilyMay @scrive @skrivaPa @scrive_UK
Functions Only
:: Input -> AnotherInput -> Output
Want to go mess around with something that isnʼt stated in the type signature. Hard
cheese. You canʼt.
Monday, August 15, 2011

13.
@heidiHarman & @greenEmilyMay @scrive @skrivaPa @scrive_UK
My, this sounds insane,
why?!
Answer: some things are easier
The thing thatʼs making functional languages like Haskell popular at
the moment is ........
Programming for Multiple
Cores
Monday, August 15, 2011

14.
@heidiHarman & @greenEmilyMay @scrive @skrivaPa @scrive_UK
How many cores does your computer
have?
How many will it have in 3 years time?
Monday, August 15, 2011

15.
@heidiHarman & @greenEmilyMay @scrive @skrivaPa @scrive_UK
Immutability Makes Multi-
Threaded Code Easier
Did you know Twitter uses a functional
language for itʼs highly threaded server
code?
Monday, August 15, 2011

16.
@heidiHarman & @greenEmilyMay @scrive @skrivaPa @scrive_UK
TypeSafe
saveAddress :: String -> Maybe Error User
newtype Email = String
saveAddress :: Email -> Maybe Error User
Monday, August 15, 2011

17.
@heidiHarman & @greenEmilyMay @scrive @skrivaPa @scrive_UK
Structure Gives Freedom
But it makes compilation
longer
> “Like a logician on your shoulder” - eric
> GHC magic
Monday, August 15, 2011

18.
@heidiHarman & @greenEmilyMay @scrive @skrivaPa @scrive_UK
Itʼs Different
> Do you miss that excited
feeling you got when you
coded as a kid. Become a
happy idiot again, learn
Haskell.
Monday, August 15, 2011

19.
@heidiHarman & @greenEmilyMay @scrive @skrivaPa @scrive_UK
Quest to Grok the Monad
> If you learn Haskell you will
quickly hear the word
“monad”. Keep calm.
Monday, August 15, 2011

20.
@heidiHarman & @greenEmilyMay @scrive @skrivaPa @scrive_UK
I love one thing more than
Haskell, Haskell coders.
Tip: if someone learns Haskell just to
work on your project, theyʼll probably
do a good job.
Monday, August 15, 2011

21.
Thank you
Monday, August 15, 2011

22.
More links about us
Lukas Duczko on distributed teams at SSES
http://www.vimeo.com/22653093
IDG
idg.se/2.1006/1.387765/arets-webbentreprenorer-lukas-duczko-och-gracjan-polak
Monday, August 15, 2011

23.
@heidiHarman & @greenEmilyMay @scrive @skrivaPa @scrive_UK
Coffetalk
Monday, August 15, 2011