Wearing the hair shirt Wearing the hair shirt - Microsoft Research

More documents

Recommendations

Info

Encapsulating it all runST :: (forall s. ST s a) -> a Higher rank type Security of encapsulation depends on parametricity Parametricity depends on <strong>the</strong>re being few polymorphic functions (e.g.. f:: a->a means f is <strong>the</strong> identity function or bottom) Monads And that depends on type classes to make non-parametric operations explicit (e.g. f :: Ord a => a -> a) And it also depends on purity (no side effects)
Shirts off to Wadler Type classes “Making ad hoc polymorphism less ad hoc” [POPL89] Monads “The essence of functional programming” [POPL92] Sexy types “Theorems for free” [FPCA89]
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 16 and 17: Example (ICFP02 prog comp) Pattern
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: Encapsulating it all data ST s a --
show all

Wearing the hair shirt Wearing the hair shirt - Microsoft Research

Create successful ePaper yourself

Delete template?

Save as template?