diff options
author | Eduardo Julian | 2018-07-10 22:19:13 -0400 |
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committer | Eduardo Julian | 2018-07-10 22:19:13 -0400 |
commit | 852410fda71621522f7707a80554140a5aac7f9c (patch) | |
tree | 85db4083a7292f7e4dcfe5c3d66ade5fdc9d24a6 /stdlib/source | |
parent | 842aba98d9213b26df3f0b37c5293d18922cf7fa (diff) |
- Implemented multi-sets.
Diffstat (limited to 'stdlib/source')
-rw-r--r-- | stdlib/source/lux/data/collection/set/multi.lux | 152 |
1 files changed, 152 insertions, 0 deletions
diff --git a/stdlib/source/lux/data/collection/set/multi.lux b/stdlib/source/lux/data/collection/set/multi.lux new file mode 100644 index 000000000..613670533 --- /dev/null +++ b/stdlib/source/lux/data/collection/set/multi.lux @@ -0,0 +1,152 @@ +## https://en.wikipedia.org/wiki/Multiset +(.module: + lux + (lux (control [equivalence #+ Equivalence] + [hash #+ Hash]) + [function] + (language [type #+ :share]) + (type abstract)) + (//// [maybe]) + (/// [list "list/" Fold<List>] + [dictionary #+ Dictionary]) + [//]) + +(abstract: #export (Set a) + {} + + (Dictionary a Nat) + + (def: #export new + (All [a] (-> (Hash a) (Set a))) + (|>> dictionary.new :abstraction)) + + (def: #export size + (All [a] (-> (Set a) Nat)) + (|>> :representation dictionary.values (list/fold n/+ +0))) + + (def: #export (add/* count elem set) + (All [a] (-> Nat a (Set a) (Set a))) + (|> set :representation (dictionary.update~ elem +0 (n/+ count)) :abstraction)) + + (def: #export add/1 + (All [a] (-> a (Set a) (Set a))) + (add/* +1)) + + (def: #export (remove/* count elem set) + (All [a] (-> Nat a (Set a) (Set a))) + (case (dictionary.get elem (:representation set)) + (#.Some current) + (let [transform (:share [a] + {(Set a) + set} + {(-> (Dictionary a Nat) (Dictionary a Nat)) + (if (n/> count current) + (dictionary.update elem (n/- count)) + (dictionary.remove elem))})] + (|> set :representation transform :abstraction)) + + #.None + set)) + + (def: #export remove/1 + (All [a] (-> a (Set a) (Set a))) + (remove/* +1)) + + (def: #export (multiplicity elem set) + (All [a] (-> a (Set a) Nat)) + (|> set :representation (dictionary.get elem) (maybe.default +0))) + + (def: #export to-list + (All [a] (-> (Set a) (List a))) + (let [append (: (All [a] (-> a Nat (List a) (List a))) + (function (append elem count output) + (case count + +0 output + _ (|> output (#.Cons elem) (append elem (dec count))))))] + (|>> :representation + dictionary.entries + (list/fold (function (_ [elem count] output) + (append elem count output)) + #.Nil)))) + + (def: #export (union parameter subject) + (All [a] (-> (Set a) (Set a) (Set a))) + (:abstraction (dictionary.merge-with n/+ (:representation parameter) (:representation subject)))) + + (def: #export (difference parameter subject) + (All [a] (-> (Set a) (Set a) (Set a))) + (|> parameter + :representation + dictionary.entries + (list/fold (function (_ [elem count] output) + (remove/* count elem output)) + subject))) + + (def: #export (intersection parameter subject) + (All [a] (-> (Set a) (Set a) (Set a))) + (|> parameter + :representation + dictionary.entries + (list/fold (function (_ [elem count] (^:representation output)) + (:abstraction (if (dictionary.contains? elem output) + (dictionary.update elem (n/min count) output) + output))) + subject))) + + (def: #export (sub? reference subject) + (All [a] (-> (Set a) (Set a) Bool)) + (|> subject + :representation + dictionary.entries + (list.every? (function (_ [elem count]) + (|> reference + :representation + (dictionary.get elem) + (maybe.default +0) + (n/>= count)))))) + + (def: #export (support set) + (All [a] (-> (Set a) (//.Set a))) + (let [(^@ set [Hash<a> _]) (:representation set)] + (|> set + dictionary.keys + (//.from-list Hash<a>)))) + + (structure: #export Equivalence<Set> (All [a] (Equivalence (Set a))) + (def: (= (^:representation reference) (^:representation sample)) + (and (n/= (dictionary.size reference) + (dictionary.size sample)) + (|> reference + dictionary.entries + (list.every? (function (_ [elem count]) + (|> sample + (dictionary.get elem) + (maybe.default +0) + (n/= count)))))))) + + (structure: #export Hash<Set> (All [a] (Hash (Set a))) + (def: eq ..Equivalence<Set>) + + (def: (hash (^:representation set)) + (let [[Hash<a> _] set] + (list/fold (function (_ [elem count] acc) + (|> elem (:: Hash<a> hash) (n/* count) (n/+ acc))) + +0 + (dictionary.entries set))))) + ) + +(def: #export (member? set elem) + (All [a] (-> (Set a) a Bool)) + (|> set (..multiplicity elem) (n/> +0))) + +(def: #export empty? + (All [a] (-> (Set a) Bool)) + (|>> ..size (n/= +0))) + +(def: #export (from-list Hash<a> subject) + (All [a] (-> (Hash a) (List a) (Set a))) + (list/fold ..add/1 (..new Hash<a>) subject)) + +(def: #export super? + (All [a] (-> (Set a) (Set a) Bool)) + (function.flip sub?)) |