Wearing the hair shirt Wearing the hair shirt - Microsoft Research
Wearing the hair shirt Wearing the hair shirt - Microsoft Research Wearing the hair shirt Wearing the hair shirt - Microsoft Research
Example (ICFP02 prog comp) Pattern match Pattern guard Guard Conditional Where clause sp_help item@(Item cur_loc cur_link _) wq vis | cur_length > limit -- Beyond limit = sp wq vis | Just vis_link = linkLength vis_link then -- Current link is no better sp wq vis else -- Current link is better emit vis item ++ sp wq vis' | otherwise -- Not visited yet = emit vis item ++ sp wq' vis' where vis’ = ... wq = ...
So much for syntax... What is important or interesting about Haskell?
- Page 1 and 2: Wearing the hair shirt A retrospect
- Page 3 and 4: Haskell is 15 years old (born FPCA
- Page 5 and 6: Timeline Sept 87: kick off Apr 90:
- Page 7 and 8: Reflections on the process The i
- Page 9: Reflections on process Self-appoin
- Page 12 and 13: Syntactic redundancy Seductive ide
- Page 14 and 15: “Expression style” Define a fun
- Page 18 and 19: What really matters?
- Page 20 and 21: But... Laziness makes it much, muc
- Page 22: Combinator libraries Recursive valu
- Page 25 and 26: Monadic I/O A value of type (IO t)
- Page 27 and 28: Connecting I/O operations (>>=) ::
- Page 29 and 30: Control structures Values of type (
- Page 31 and 32: Monads Exceptions type Exn a = E
- Page 33 and 34: The IO monad The IO monad allows
- Page 35 and 36: What have we achieved? ...without
- Page 37 and 38: Open challenge 1 Open problem: the
- Page 39 and 40: Monad summary Monads are a beautif
- Page 41 and 42: What really matters? Laziness Purit
- Page 44 and 45: Type classes class Eq a where (==)
- Page 46 and 47: Type classes over time Type classe
- Page 48 and 49: Quickcheck propRev :: [Int] -> Bool
- Page 50 and 51: Extensiblity Like OOP, one can add
- Page 52 and 53: Type-based dispatch class Num a whe
- Page 54 and 55: Cool generalisations Multi-paramet
- Page 56: Type classes summary A much more f
- Page 59 and 60: Is sexy good? Yes! Well typed prog
- Page 61 and 62: Destination = F w
- Page 63 and 64: Modules Porsche High power, but poo
- Page 65 and 66: Encapsulating it all data ST s a --
Example (ICFP02 prog comp)<br />
Pattern<br />
match<br />
Pattern<br />
guard<br />
Guard<br />
Conditional<br />
Where<br />
clause<br />
sp_help item@(Item cur_loc cur_link _) wq vis<br />
| cur_length > limit -- Beyond limit<br />
= sp wq vis<br />
| Just vis_link = linkLength vis_link <strong>the</strong>n<br />
-- Current link is no better<br />
sp wq vis<br />
else<br />
-- Current link is better<br />
emit vis item ++ sp wq vis'<br />
| o<strong>the</strong>rwise -- Not visited yet<br />
= emit vis item ++ sp wq' vis'<br />
where<br />
vis’ = ...<br />
wq = ...
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