Programmation en Clojique

Prolog is this weird old language that established the paradigm of logic programming. Once heralded as the solution to all AI problems, it is now considered a niche language. Luckily, many languages have adopted ideas from Prolog, such as Clojure with core.logic. In this talk, I would like to introduce Prolog’s programming model and showcase some programming domains in which it allows for very concise, elegant programs.

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1. P r o g r a m m a t i o n e n C l o g i q u e L a r s H u p e l : c l o j u r e D 2 0 2 0 - 0 2 - 2 9
2. (defne presentation [orateur] ([:lars] (fresh [questions] (blague :drole) #_(rire) (introduction :corelogic) (fonctions :cool) (audience questions) (repondre questions))))
3. P r o g r a m m a t i o n e n C l o g i q u e L a r s H u p e l : c l o j u r e D 2 0 2 0 - 0 2 - 2 9
4. (defne presentation [speaker] ([:lars] (fresh [questions] (joke :funny) #_(laugh) (introduction :corelogic) (features :cool) (audience questions) (answer questions))))
5. (defne presentation [speaker] ([:lars] (fresh [questions] (joke :funny) #_(laugh) (introduction :corelogic) (features :cool) (audience questions) (answer questions))))
6. W h o i n v e n t e d l o g i c p r o g r a m m i n g ? “ 1 . T h e w o r l d i s e v e r y t h i n g t h a t i s t h e c a s e . 1 .1 T h e w o r l d i s t h e t o t a l i t y o f f a c t s , n o t o f t h i n g s . 1 .1 1 T h e w o r l d i s d e t e r m i n e d b y t h e f a c t s , a n d b y t h e s e b e i n g a l l t h e f a c t s . ”
7. W h o i n v e n t e d l o g i c p r o g r a m m i n g ? “ 1 . T h e w o r l d i s e v e r y t h i n g t h a t i s t h e c a s e . 1 .1 T h e w o r l d i s t h e t o t a l i t y o f f a c t s , n o t o f t h i n g s . 1 .1 1 T h e w o r l d i s d e t e r m i n e d b y t h e f a c t s , a n d b y t h e s e b e i n g a l l t h e f a c t s . ” – L u d w i g W i t t g e n s t e i n , 1 9 1 8
8. (defne presentation [speaker] ([:lars] (fresh [questions] (joke :funny) #_(laugh) (introduction :corelogic) (features :cool) (audience questions) (answer questions))))
9. W h o i n v e n t e d P r o l o g ? • a p p e a r e d i n t h e e a r l y 7 0 s i n F r a n c e • o r i g i n a l d e v e l o p e r s : A l a i n C o l m e r a u e r a n d P h i l i p p e R o u s s e l • u s e d t h e .pl e x t e n s i o n b e f o r e P e r l • r a d i c a l l y d i f f e r e n t p r o g r a m m i n g p a r a d i g m • t h i s t a l k : u s i n g c o r e . l o g i c s y n t a x
10. A b r i e f p r i m e r o n P r o l o g 1 . P r o l o g p r o g r a m s a r e s e q u e n c e s o f r u l e s ( o r c l a u s e s ) .
11. A b r i e f p r i m e r o n P r o l o g 1 . P r o l o g p r o g r a m s a r e s e q u e n c e s o f r u l e s ( o r c l a u s e s ) . 2 . R u l e s c a n h a v e a r g u m e n t s .
12. A b r i e f p r i m e r o n P r o l o g 1 . P r o l o g p r o g r a m s a r e s e q u e n c e s o f r u l e s ( o r c l a u s e s ) . 2 . R u l e s c a n h a v e a r g u m e n t s . 3 . R u l e s c a n h a v e c o n d i t i o n s .
13. A b r i e f p r i m e r o n P r o l o g 1 . P r o l o g p r o g r a m s a r e s e q u e n c e s o f r u l e s ( o r c l a u s e s ) . 2 . R u l e s c a n h a v e a r g u m e n t s . 3 . R u l e s c a n h a v e c o n d i t i o n s . 4 . P r o g r a m s c a n b e q u e r i e d .
14. A b r i e f p r i m e r o n P r o l o g 1 . P r o l o g p r o g r a m s a r e s e q u e n c e s o f r u l e s ( o r c l a u s e s ) . 2 . R u l e s c a n h a v e a r g u m e n t s . 3 . R u l e s c a n h a v e c o n d i t i o n s . 4 . P r o g r a m s c a n b e q u e r i e d . 5 . A n y t h i n g t h a t i s n o t i n t h e p r o g r a m i s n o t t r u e .
15. E r l a n g , i n s p i r e d b y P r o l o g “ T h e f i r s t i n t e r p r e t e r w a s a s i m p l e P r o l o g m e t a i n t e r p r e t e r w h i c h a d d e d t h e n o t i o n o f a s u s p e n d a b l e p r o c e s s t o P r o l o g . . . [ i t ] w a s r a p i d l y m o d i f i e d ( a n d r e - w r i t t e n ) . . . ” – A r m s t r o n g , V i r d i n g , W i l l i a m s : U s e o f P r o l o g f o r d e v e l o p i n g a n e w p r o g r a m m i n g l a n g u a g e
16. H e l l o W o r l d ! P r o g r a m (defn hi [])
17. H e l l o W o r l d ! P r o g r a m (defn hi []) I n t e r p r e t e r => (run* (hi)) (_0)
18. H e l l o W o r l d ! P r o g r a m (defn hi []) I n t e r p r e t e r => (run* (hi)) (_0) (defn hello [x] (== x :world))
19. H e l l o W o r l d ! P r o g r a m (defn hi []) I n t e r p r e t e r => (run* (hi)) (_0) (defn hello [x] (== x :world)) => (run* [_] (hello :world)) (_0)
20. H e l l o W o r l d ! P r o g r a m (defn hi []) I n t e r p r e t e r => (run* (hi)) (_0) (defn hello [x] (== x :world)) => (run* [_] (hello :world)) (_0) => (run* [_] (hello :coworld)) ()
21. H e l l o W o r l d ! P r o g r a m (defn hi []) I n t e r p r e t e r => (run* (hi)) (_0) (defn hello [x] (== x :world)) => (run* [_] (hello :world)) (_0) => (run* [_] (hello :coworld)) ()
22. H e l l o W o r l d ! P r o g r a m (defn hi []) I n t e r p r e t e r => (run* (hi)) (_0) (defn hello [x] (== x :world)) => (run* [_] (hello :world)) (_0) => (run* [_] (hello :coworld)) () => (run* [x] (hello x)) (:world)
23. A s m a l l p r o g r a m F a c t s (defne location [place in] ([:munich :germany]) ([:augsburg :germany]) ([:germany :europe]) ([:london :unitedkingdom]) ([:unitedkingdom :europe]))
24. A s m a l l p r o g r a m F a c t s (defne location [place in] ([:munich :germany]) ([:augsburg :germany]) ([:germany :europe]) ([:london :unitedkingdom]) ([:unitedkingdom :europe])) EU Customs Union Council of Europe European Union EEA BSEC Eurozone Benelux Baltic Assembly EFTA GUAM CEFTA Schengen Area Union State Nordic Council Visegrád Group Common Travel Area Monetary agreement with the EU
25. A s m a l l p r o g r a m F a c t s (defne location [place in] ([:munich :germany]) ([:augsburg :germany]) ([:germany :europe]) ([:london :unitedkingdom]) ([:unitedkingdom :europe]))
26. A s m a l l p r o g r a m F a c t s (defne location [place in] ([:munich :germany]) ([:augsburg :germany]) ([:germany :europe]) ([:london :unitedkingdom]) ([:unitedkingdom :europe])) R u l e s (defn neighbour [x y] (fresh [z] (location x z) (location y z)))
27. A s m a l l p r o g r a m F a c t s (defne location [place in] ([:munich :germany]) ([:augsburg :germany]) ([:germany :europe]) ([:london :unitedkingdom]) ([:unitedkingdom :europe])) R u l e s (defn is-in [x y] (conde [(location x y)] [(fresh (z) (location x z) (is-in z y))]))
28. (defne presentation [speaker] ([:lars] (fresh [questions] (joke :funny) #_(laugh) (introduction :corelogic) (features :cool) (audience questions) (answer questions))))
29. B a c k t r a c k i n g (defn best-boy [x] (fresh [y] (dog :good x) (colour :dark_brown x) (behind x y) (colour :light_brown y)))
30. B a c k t r a c k i n g (defn best-boy [x] (fresh [y] (dog :good x) (colour :dark_brown x) (behind x y) (colour :light_brown y)))
31. B a c k t r a c k i n g (defn best-boy [x] (fresh [y] (dog :good x) (colour :dark_brown x) (behind x y) (colour :light_brown y)))
32. B a c k t r a c k i n g (defn best-boy [x] (fresh [y] (dog :good x) (colour :dark_brown x) (behind x y) (colour :light_brown y)))
33. B a c k t r a c k i n g (defn best-boy [x] (fresh [y] (dog :good x) (colour :dark_brown x) (behind x y) (colour :light_brown y)))
34. B a c k t r a c k i n g (defn best-boy [x] (fresh [y] (dog :good x) (colour :dark_brown x) (behind x y) (colour :light_brown y)))
35. B a c k t r a c k i n g (defn best-boy [x] (fresh [y] (dog :good x) (colour :dark_brown x) (behind x y) (colour :light_brown y)))
36. B a c k t r a c k i n g (defn best-boy [x] (fresh [y] (dog :good x) (colour :dark_brown x) (behind x y) (colour :light_brown y)))
37. B a c k t r a c k i n g (defn best-boy [x] (fresh [y] (dog :good x) (colour :dark_brown x) (behind x y) (colour :light_brown y)))
38. B a c k t r a c k i n g (defn best-boy [x] (fresh [y] (dog :good x) (colour :dark_brown x) (behind x y) (colour :light_brown y)))
39. B i - d i r e c t i o n a l c o m p u t i n g f : I → O
40. B i - d i r e c t i o n a l c o m p u t i n g f : I → O
41. B i - d i r e c t i o n a l c o m p u t i n g f : I → O R : (I × O ) → {0 , 1 }
42. B i - d i r e c t i o n a l c o m p u t i n g C l o j u r e (concat xs ys)
43. B i - d i r e c t i o n a l c o m p u t i n g C l o j u r e (concat xs ys) c o r e . l o g i c (appendo xs ys zs)
44. N o t a s i l v e r b u l l e t . . . H o w t o r e v e r s e flatten?
45. W h a t a b o u t n u m b e r s ? => (run* [x y] (membero x [1 2 3]) (== y 2) (> x y))
46. W h a t a b o u t n u m b e r s ? => (run* [x y] (membero x [1 2 3]) (== y 2) (> x y))
47. W h a t a b o u t n u m b e r s ? => (run* [x y] (membero x [1 2 3]) (== y 2) (> x y)) => (require '[clojure.core.logic.fd :as fd]) => (run* [x y] (membero x [1 2 3]) (== y 2) (fd/> x y)) ([3 2])
48. F a c t d a t a b a s e s H o w t o m o d e l f a c t s e v o l v i n g o v e r t i m e ?
49. F a c t d a t a b a s e s H o w t o m o d e l f a c t s e v o l v i n g o v e r t i m e ? S e l f - m o d i f y i n g c o d e ?
50. F a c t d a t a b a s e s H o w t o m o d e l f a c t s e v o l v i n g o v e r t i m e ? S e l f - m o d i f y i n g c o d e ? J u s t l i k e i n S Q L !
51. P L D B (pldb/db-rel location p q) (def facts (pldb/db [location :munich :germany] [location :augsburg :germany] [location :germany :europe] [location :london :unitedkingdom] [location :unitedkingdom :europe]))
52. P L D B a s r e a l d a t a b a s e • d a t a m o d e l i s s i m i l a r t o S Q L : s e t s o f t u p l e s ( “ r e l a t i o n s ” ) • P L D B i s s t a t i c & i m m u t a b l e
53. C o n s t r a i n t s o l v i n g P u z z l e T h e r e a r e f i v e h o u s e s . 1 . T h e E n g l i s h p e r s o n l i v e s i n t h e r e d h o u s e . 2 . T h e S w e d i s h p e r s o n o w n s a d o g . 3 . T h e D a n i s h p e r s o n l i k e s t o d r i n k t e a . 4 . T h e g r e e n h o u s e i s l e f t t o t h e w h i t e h o u s e . 5 . T h e o w n e r o f t h e g r e e n h o u s e d r i n k s c o f f e e . 6 . . . .
54. G r a m m a r s
55. G r a m m a r s
56. G r a m m a r s
57. G r a m m a r s (def-->e det [d] ([[:d 'the]] '[the]) ([[:d 'a]] '[a])) (def-->e noun-phrase [n] ([[:np ?d ?n]] (det ?d) (noun ?n)))
58. P r o l o g i s f o r p a r s i n g ? “ T h e p r o g r a m m i n g l a n g u a g e . . . w a s b o r n o f a p r o j e c t a i m e d n o t a t p r o d u c i n g a p r o g r a m m i n g l a n g u a g e b u t a t p r o c e s s i n g n a t u r a l l a n - g u a g e s ; i n t h i s c a s e , F r e n c h . ” – C o l m e r a u e r , R o u s s e l : T h e B i r t h o f P r o l o g
59. P r o l o g i s f o r p a r s i n g ? “ T h e p r o g r a m m i n g l a n g u a g e . . . w a s b o r n o f a p r o j e c t a i m e d n o t a t p r o d u c i n g a p r o g r a m m i n g l a n g u a g e b u t a t p r o c e s s i n g n a t u r a l l a n - g u a g e s ; i n t h i s c a s e , F r e n c h . ” – C o l m e r a u e r , R o u s s e l : T h e B i r t h o f P r o l o g
60. (defne presentation [speaker] ([:lars] (fresh [questions] (joke :funny) #_(laugh) (introduction :corelogic) (features :cool) (audience questions) (answer questions))))
61. Q & A L a r s H u p e l � l a r s . h u p e l @ i n n o q . c o m � @ l a r s r _ h w w w . i n n o q . c o m i n n o Q D e u t s c h l a n d G m b H K r i s c h e r s t r . 1 0 0 4 0 7 8 9 M o n h e i m a . R h . G e r m a n y + 4 9 2 1 7 3 3 3 6 6 - 0 O h l a u e r S t r . 4 3 1 0 9 9 9 B e r l i n G e r m a n y L u d w i g s t r . 1 8 0 E 6 3 0 6 7 O f f e n b a c h G e r m a n y K r e u z s t r . 1 6 8 0 3 3 1 M ü n c h e n G e r m a n y c / o W e W o r k H e r m a n n s t r a s s e 1 3 2 0 0 9 5 H a m b u r g G e r m a n y i n n o Q S c h w e i z G m b H G e w e r b e s t r . 1 1 C H - 6 3 3 0 C h a m S w i t z e r l a n d + 4 1 4 1 7 4 3 0 1 1 1 A l b u l a s t r . 5 5 8 0 4 8 Z ü r i c h S w i t z e r l a n d
62. L A R S H U P E L C o n s u l t a n t i n n o Q D e u t s c h l a n d G m b H L a r s e n j o y s p r o g r a m m i n g i n a v a r i e t y o f l a n - g u a g e s , i n c l u d i n g S c a l a , H a s k e l l , a n d R u s t . H e i s k n o w n a s a f r e q u e n t c o n f e r e n c e s p e a k e r a n d o n e o f t h e f o u n d e r s o f t h e T y p e l e v e l i n i t i a t i v e w h i c h i s d e d i c a t e d t o p r o v i d i n g p r i n c i p l e d , t y p e - d r i v e n S c a l a l i b r a r i e s .
63. I m a g e s o u r c e s • T i t l e ( m a p ) : https://pixabay.com/photos/world-europe-map-connections-1264062/ • S h i b a r o w : https://www.pinterest.de/pin/424112489894679416/ • S h i b a w i t h m l e m : https://www.reddit.com/r/mlem/comments/6tc1of/shibe_doing_a_mlem/ • H a p p y d o g : https://www.rover.com/blog/is-my-dog-happy/ • K i d w i t h c r o s s e d a r m s : https: //www.psychologytoday.com/us/blog/spycatcher/201410/9-truths-exposing-myth-about-body-language • N o a m C h o m s k y : https://en.wikipedia.org/wiki/File:Noam_Chomsky_Toronto_2011.jpg • A l a i n C o l m e r a u e r : https://de.wikipedia.org/wiki/Datei:A-Colmerauer_web-800x423.jpg • J o e A r m s t r o n g : E r l a n g , t h e M o v i e • S i g n a t u r e s : http://www.swi-prolog.org/pldoc/man?section=preddesc • Z e b r a p u z z l e : S t a c k O v e r f l o w c o n t r i b u t o r s ( https://stackoverflow.com/q/11122814/4776939) • O w l : https://www.theloop.ca/angry-owl-terrorizes-oregon-joggers/ • C l o c k : https://pixabay.com/photos/clock-alarm-alarm-clock-dial-time-1031503/ • F i l e s : https://pixabay.com/photos/files-ddr-archive-1633406/