From 020f625b3d94cdb00242ead397595eeff842533c Mon Sep 17 00:00:00 2001 From: Eduardo Julian Date: Thu, 30 Mar 2017 21:37:41 -0400 Subject: - Implemented ordered sets by means of red-black trees. --- stdlib/source/lux/data/coll/ordered.lux | 493 +++++++++++++++++++++++++++++ stdlib/test/test/lux/data/coll/ordered.lux | 68 ++++ stdlib/test/tests.lux | 1 + 3 files changed, 562 insertions(+) create mode 100644 stdlib/source/lux/data/coll/ordered.lux create mode 100644 stdlib/test/test/lux/data/coll/ordered.lux (limited to 'stdlib') diff --git a/stdlib/source/lux/data/coll/ordered.lux b/stdlib/source/lux/data/coll/ordered.lux new file mode 100644 index 000000000..1db97519b --- /dev/null +++ b/stdlib/source/lux/data/coll/ordered.lux @@ -0,0 +1,493 @@ +(;module: + lux + (lux (control monad + eq + [ord #+ Ord]) + (data (coll [list "" Monad "L/" Monoid Fold]) + ["p" product] + ["M" maybe #+ Functor]) + [compiler] + (macro [ast] + ["s" syntax #+ syntax: Syntax]))) + +(def: error-message Text "Invariant violation") + +(type: Color #Red #Black) + +(type: (Node a) + {#color Color + #value a + #left (Maybe (Node a)) + #right (Maybe (Node a))}) + +(do-template [ ] + [(def: ( value left right) + (All [a] (-> a (Maybe (Node a)) (Maybe (Node a)) (Node a))) + {#color + #value value + #left left + #right right})] + + [red #Red] + [black #Black] + ) + +(type: #export (Set a) + {#order (Ord a) + #root (Maybe (Node a))}) + +(def: #export (new Ord) + (All [a] (-> (Ord a) (Set a))) + {#order Ord + #root #;None}) + +(def: #export (member? tree elem) + (All [a] (-> (Set a) a Bool)) + (let [(^open "T/") (get@ #order tree)] + (loop [node (get@ #root tree)] + (case node + #;None + false + + (#;Some node) + (or (T/= elem (get@ #value node)) + (recur (get@ #left node)) + (recur (get@ #right node))))))) + +(do-template [ ] + [(def: #export ( tree) + (All [a] (-> (Set a) (Maybe a))) + (loop [node (get@ #root tree)] + (case node + #;None + #;None + + (#;Some node) + (recur (get@ node)))))] + + [min #left] + [max #right] + ) + +(do-template [ ] + [(def: #export ( tree) + (All [a] (-> (Set a) Nat)) + (loop [node (get@ #root tree)] + (case node + #;None + +0 + + (#;Some node) + (n.inc ( (recur (get@ #left node)) + (recur (get@ #right node)))))))] + + [size n.+] + [depth n.max] + ) + +(do-template [ ] + [(def: ( self) + (All [a] (-> (Node a) (Node a))) + (case (get@ #color self) + + (set@ #color self) + + + + ))] + + [blacken #Red #Black self] + [redden #Black #Red (error! error-message)] + ) + +(syntax: (as-is ast) + (wrap (list ast))) + +(def: (balance-left-add parent self) + (All [a] (-> (Node a) (Node a) (Node a))) + (let% [ (as-is (black (get@ #value parent) + (#;Some self) + (get@ #right parent)))] + (case (get@ #color self) + #Red + (case (get@ #left self) + (^=> (#;Some left) + [(get@ #color left) #Red]) + (red (get@ #value self) + (#;Some (blacken left)) + (#;Some (black (get@ #value parent) + (get@ #right self) + (get@ #right parent)))) + + _ + (case (get@ #right self) + (^=> (#;Some right) + [(get@ #color right) #Red]) + (red (get@ #value right) + (#;Some (black (get@ #value self) + (get@ #left self) + (get@ #left right))) + (#;Some (black (get@ #value parent) + (get@ #right right) + (get@ #right parent)))) + + _ + )) + + #Black + + ))) + +(def: (balance-right-add parent self) + (All [a] (-> (Node a) (Node a) (Node a))) + (let% [ (as-is (black (get@ #value parent) + (get@ #left parent) + (#;Some self)))] + (case (get@ #color self) + #Red + (case (get@ #right self) + (^=> (#;Some right) + [(get@ #color right) #Red]) + (red (get@ #value self) + (#;Some (black (get@ #value parent) + (get@ #left parent) + (get@ #left self))) + (#;Some (blacken right))) + + _ + (case (get@ #left self) + (^=> (#;Some left) + [(get@ #color left) #Red]) + (red (get@ #value left) + (#;Some (black (get@ #value parent) + (get@ #left parent) + (get@ #left left))) + (#;Some (black (get@ #value self) + (get@ #right left) + (get@ #right self)))) + + _ + )) + + #Black + + ))) + +(def: (add-left addition center) + (All [a] (-> (Node a) (Node a) (Node a))) + (case (get@ #color center) + #Red + (red (get@ #value center) (#;Some addition) (get@ #right center)) + + #Black + (balance-left-add center addition) + )) + +(def: (add-right addition center) + (All [a] (-> (Node a) (Node a) (Node a))) + (case (get@ #color center) + #Red + (red (get@ #value center) (get@ #left center) (#;Some addition)) + + #Black + (balance-right-add center addition) + )) + +(def: #export (add elem tree) + (All [a] (-> a (Set a) (Set a))) + (let [(^open "T/") (get@ #order tree) + root' (loop [?root (get@ #root tree)] + (case ?root + #;None + (#;Some (red elem #;None #;None)) + + (#;Some root) + (let [reference (get@ #value root)] + (let% [ (do-template [ ] + [( reference elem) + (let [side-root (get@ root) + outcome (recur side-root)] + (if (is side-root outcome) + ?root + (#;Some ( (default (undefined) outcome) + root))))] + + [T/< #left add-left] + [T/> #right add-right] + )] + (cond + + ## (T/= reference elem) + ?root + ))) + ))] + (set@ #root root' tree))) + +(def: (left-balance value ?left ?right) + (All [a] (-> a (Maybe (Node a)) (Maybe (Node a)) (Node a))) + (case ?left + (^=> (#;Some left) + [(get@ #color left) #Red] + [(get@ #left left) (#;Some left.left)] + [(get@ #color left.left) #Red]) + (red (get@ #value left) + (#;Some (blacken left.left)) + (#;Some (black value (get@ #right left) ?right))) + + (^=> (#;Some left) + [(get@ #color left) #Red] + [(get@ #right left) (#;Some left.right)] + [(get@ #color left.right) #Red]) + (red (get@ #value left.right) + (#;Some (black (get@ #value left) + (get@ #left left) + (get@ #left left.right))) + (#;Some (black value + (get@ #right left.right) + ?right))) + + _ + (black value ?left ?right))) + +(def: (right-balance value ?left ?right) + (All [a] (-> a (Maybe (Node a)) (Maybe (Node a)) (Node a))) + (case ?right + (^=> (#;Some right) + [(get@ #color right) #Red] + [(get@ #right right) (#;Some right.right)] + [(get@ #color right.right) #Red]) + (red (get@ #value right) + (#;Some (black value ?left (get@ #left right))) + (#;Some (blacken right.right))) + + (^=> (#;Some right) + [(get@ #color right) #Red] + [(get@ #left right) (#;Some right.left)] + [(get@ #color right.left) #Red]) + (red (get@ #value right.left) + (#;Some (black value ?left (get@ #left right.left))) + (#;Some (black (get@ #value right) + (get@ #right right.left) + (get@ #right right)))) + + _ + (black value ?left ?right))) + +(def: (balance-left-remove value ?left ?right) + (All [a] (-> a (Maybe (Node a)) (Maybe (Node a)) (Node a))) + (case ?left + (^=> (#;Some left) + [(get@ #color left) #Red]) + (red value (#;Some (blacken left)) ?right) + + _ + (case ?right + (^=> (#;Some right) + [(get@ #color right) #Black]) + (right-balance value ?left (#;Some (redden right))) + + (^=> (#;Some right) + [(get@ #color right) #Red] + [(get@ #left right) (#;Some right.left)] + [(get@ #color right.left) #Black]) + (red (get@ #value right.left) + (#;Some (black value ?left (get@ #left right.left))) + (#;Some (right-balance (get@ #value right) + (get@ #right right.left) + (:: Functor map redden (get@ #right right))))) + + _ + (error! error-message)) + )) + +(def: (balance-right-remove value ?left ?right) + (All [a] (-> a (Maybe (Node a)) (Maybe (Node a)) (Node a))) + (case ?right + (^=> (#;Some right) + [(get@ #color right) #Red]) + (red value ?left (#;Some (blacken right))) + + _ + (case ?left + (^=> (#;Some left) + [(get@ #color left) #Black]) + (left-balance value (#;Some (redden left)) ?right) + + (^=> (#;Some left) + [(get@ #color left) #Red] + [(get@ #right left) (#;Some left.right)] + [(get@ #color left.right) #Black]) + (red (get@ #value left.right) + (#;Some (left-balance (get@ #value left) + (:: Functor map redden (get@ #left left)) + (get@ #left left.right))) + (#;Some (black value (get@ #right left.right) ?right))) + + _ + (error! error-message) + ))) + +(def: (prepend ?left ?right) + (All [a] (-> (Maybe (Node a)) (Maybe (Node a)) (Maybe (Node a)))) + (case [?left ?right] + [#;None _] + ?right + + [_ #;None] + ?left + + [(#;Some left) (#;Some right)] + (case [(get@ #color left) (get@ #color right)] + [#Red #Red] + (do M;Monad + [fused (prepend (get@ #right left) (get@ #right right))] + (case (get@ #color fused) + #Red + (wrap (red (get@ #value fused) + (#;Some (red (get@ #value left) + (get@ #left left) + (get@ #left fused))) + (#;Some (red (get@ #value right) + (get@ #right fused) + (get@ #right right))))) + + #Black + (wrap (red (get@ #value left) + (get@ #left left) + (#;Some (red (get@ #value right) + (#;Some fused) + (get@ #right right))))))) + + [#Red #Black] + (#;Some (red (get@ #value left) + (get@ #left left) + (prepend (get@ #right left) + ?right))) + + [#Black #Red] + (#;Some (red (get@ #value right) + (prepend ?left + (get@ #left right)) + (get@ #right right))) + + [#Black #Black] + (do M;Monad + [fused (prepend (get@ #right left) (get@ #left right))] + (case (get@ #color fused) + #Red + (wrap (red (get@ #value fused) + (#;Some (black (get@ #value left) + (get@ #left left) + (get@ #left fused))) + (#;Some (black (get@ #value right) + (get@ #right fused) + (get@ #right right))))) + + #Black + (wrap (balance-left-remove (get@ #value left) + (get@ #left left) + (#;Some (black (get@ #value right) + (#;Some fused) + (get@ #right right))))) + )) + ))) + +(def: #export (remove elem tree) + (All [a] (-> a (Set a) (Set a))) + (let [(^open "T/") (get@ #order tree) + [?root found?] (loop [?root (get@ #root tree)] + (case ?root + #;None + [#;None false] + + (#;Some root) + (let [root-val (get@ #value root)] + (if (T/= root-val elem) + [(prepend (get@ #left root) + (get@ #right root)) + true] + (let [go-left? (T/< root-val elem)] + (case (recur (if go-left? + (get@ #left root) + (get@ #right root))) + [#;None false] + [#;None false] + + [side-outcome _] + (if go-left? + (case (get@ #left root) + (^=> (#;Some left) + [(get@ #color left) #Black]) + [(#;Some (balance-left-remove root-val side-outcome (get@ #right root))) + false] + + _ + [(#;Some (red root-val side-outcome (get@ #right root))) + false]) + (case (get@ #right root) + (^=> (#;Some right) + [(get@ #color right) #Black]) + [(#;Some (balance-right-remove root-val (get@ #left root) side-outcome)) + false] + + _ + [(#;Some (red root-val (get@ #left root) side-outcome)) + false]) + ))) + )) + ))] + (case ?root + #;None + (if found? + (set@ #root ?root tree) + tree) + + (#;Some root) + (set@ #root (#;Some (blacken root)) tree) + ))) + +(def: #export (from-list Ord list) + (All [a] (-> (Ord a) (List a) (Set a))) + (L/fold add (new Ord) list)) + +(def: #export (to-list tree) + (All [a] (-> (Set a) (List a))) + (loop [node (get@ #root tree)] + (case node + #;None + (list) + + (#;Some node') + ($_ L/append + (recur (get@ #left node')) + (list (get@ #value node')) + (recur (get@ #right node')))))) + +(def: #export (union left right) + (All [a] (-> (Set a) (Set a) (Set a))) + (L/fold add right (to-list left))) + +(def: #export (intersection left right) + (All [a] (-> (Set a) (Set a) (Set a))) + (|> (to-list right) + (list;filter (member? left)) + (from-list (get@ #order right)))) + +(def: #export (difference param subject) + (All [a] (-> (Set a) (Set a) (Set a))) + (|> (to-list subject) + (list;filter (. not (member? param))) + (from-list (get@ #order subject)))) + +(def: #export (sub? super sub) + (All [a] (-> (Set a) (Set a) Bool)) + (list;every? (member? super) (to-list sub))) + +(def: #export (super? sub super) + (All [a] (-> (Set a) (Set a) Bool)) + (sub? super sub)) + +(struct: #export Eq (All [a] (Eq (Set a))) + (def: (= reference sample) + (:: (list;Eq (get@ [#order #ord;eq] sample)) + = (to-list reference) (to-list sample)))) diff --git a/stdlib/test/test/lux/data/coll/ordered.lux b/stdlib/test/test/lux/data/coll/ordered.lux new file mode 100644 index 000000000..213a568c1 --- /dev/null +++ b/stdlib/test/test/lux/data/coll/ordered.lux @@ -0,0 +1,68 @@ +(;module: + lux + (lux [io] + (control monad) + (data (coll ["&" ordered] + ["S" set] + [list "" Fold]) + [number] + text/format) + ["R" math/random] + pipe) + lux/test) + +(def: gen-nat + (R;Random Nat) + (|> R;nat + (:: R;Monad map (n.% +100)))) + +(test: "Sets" + [sizeL gen-nat + sizeR gen-nat + setL (|> (R;set number;Hash sizeL gen-nat) + (:: @ map (|>. S;to-list (&;from-list number;Ord)))) + setR (|> (R;set number;Hash sizeR gen-nat) + (:: @ map (|>. S;to-list (&;from-list number;Ord)))) + #let [(^open "&/") &;Eq]] + ($_ seq + (assert "I can query the size of a set." + (n.= sizeL (&;size setL))) + + (assert "Converting sets to/from lists can't change their values." + (|> setL + &;to-list (&;from-list number;Ord) + (&/= setL))) + + (assert "Order is preserved." + (let [listL (&;to-list setL) + (^open "L/") (list;Eq number;Eq)] + (L/= listL + (list;sort n.< listL)))) + + (assert "Every set is a sub-set of the union of itself with another." + (let [setLR (&;union setL setR)] + (and (&;sub? setLR setL) + (&;sub? setLR setR)))) + + (assert "Every set is a super-set of the intersection of itself with another." + (let [setLR (&;intersection setL setR)] + (and (&;super? setLR setL) + (&;super? setLR setR)))) + + (assert "Union with the empty set leaves a set unchanged." + (&/= setL + (&;union (&;new number;Ord) + setL))) + + (assert "Intersection with the empty set results in the empty set." + (let [empty-set (&;new number;Ord)] + (&/= empty-set + (&;intersection empty-set setL)))) + + (assert "After substracting a set A from another B, no member of A can be a member of B." + (let [sub (&;difference setR setL)] + (not (list;any? (&;member? sub) (&;to-list setR))))) + + (assert "Every member of a set must be identifiable." + (list;every? (&;member? setL) (&;to-list setL))) + )) diff --git a/stdlib/test/tests.lux b/stdlib/test/tests.lux index c066e551e..ffe0628bf 100644 --- a/stdlib/test/tests.lux +++ b/stdlib/test/tests.lux @@ -45,6 +45,7 @@ [list] [queue] [set] + [ordered] [stack] ## [vector] (tree [rose] -- cgit v1.2.3