1. Wednesday, August 8, 12

2. #speakerConf München
my findings in trying to
use this functional
programming business you
guys keep talking about
phil calçado
@pcalcado
http://philcalcado.com
Wednesday, August 8, 12

3. my question:
are tests good design aid
for programming with
pure-ish functions?
Wednesday, August 8, 12

4. asking the FP community
“dafuq? just use [Quick|Scala]Check LOL”
“reason about your code or do not
reason about your code,
there is no try”
Wednesday, August 8, 12

5. silly example:
we have iOS push
notifications; let’s
introduce android
Wednesday, August 8, 12

6. written w/o tests
Wednesday, August 8, 12

7. writing some tests
Wednesday, August 8, 12

8. making it pass
Wednesday, August 8, 12

9. introducing android
Wednesday, August 8, 12

10. “Every function should have:
- A single specific purpose
- If possible, a generally useful purpose
- A meaningful name
- A structure that is simple to
understand
- An interface that is simple yet general
enough”
Peter Norvig, Good Lisp Programming Style - http://bit.ly/u6JTPt
Wednesday, August 8, 12

11. other findings
Wednesday, August 8, 12

12. other findings
functional vs. object
impedance happens all the
time
Wednesday, August 8, 12

13. Wednesday, August 8, 12

14. stages must interact with
ruby libs. options:
1) give up “functional” stages
2) object-functional mapping
layer
Wednesday, August 8, 12

15. other findings
there is something going on
between category theory
and software engineering *
* you know, the fairly anecdotal body of knowledge we use
Wednesday, August 8, 12

16. other findings
more types = less typing
Wednesday, August 8, 12

17. other findings
more types = less typing
ORLY? how
much less?
Wednesday, August 8, 12

18. next question:
how much of testing as
design aid can static
typing replace?
Wednesday, August 8, 12

19. phil calçado
http://philcalcado.com
@pcalcado
www.soundcloud.com
Wednesday, August 8, 12