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Diffstat (limited to 'lib/pure/collections/intsets.nim')
| -rw-r--r-- | lib/pure/collections/intsets.nim | 694 |
1 files changed, 7 insertions, 687 deletions
diff --git a/lib/pure/collections/intsets.nim b/lib/pure/collections/intsets.nim index 3be453e29..e4c216d08 100644 --- a/lib/pure/collections/intsets.nim +++ b/lib/pure/collections/intsets.nim @@ -7,698 +7,18 @@ # distribution, for details about the copyright. # -## The ``intsets`` module implements an efficient `int` set implemented as a -## `sparse bit set`:idx:. -## -## **Note**: Currently the assignment operator ``=`` for ``IntSet`` -## performs some rather meaningless shallow copy. Since Nim currently does -## not allow the assignment operator to be overloaded, use `assign proc -## <#assign,IntSet,IntSet>`_ to get a deep copy. -## +## Deprecated by the generic `PackedSet` for ordinal sparse sets. ## **See also:** -## * `sets module <sets.html>`_ for more general hash sets +## * `Ordinal packed sets module <packedsets.html>`_ for more general packed sets import std/private/since -import hashes +import std/packedsets +export packedsets type - BitScalar = uint + IntSet* = PackedSet[int] -const - InitIntSetSize = 8 # must be a power of two! - TrunkShift = 9 - BitsPerTrunk = 1 shl TrunkShift # needs to be a power of 2 and - # divisible by 64 - TrunkMask = BitsPerTrunk - 1 - IntsPerTrunk = BitsPerTrunk div (sizeof(BitScalar) * 8) - IntShift = 5 + ord(sizeof(BitScalar) == 8) # 5 or 6, depending on int width - IntMask = 1 shl IntShift - 1 +proc toIntSet*(x: openArray[int]): IntSet {.since: (1, 3), inline.} = toPackedSet[int](x) -type - PTrunk = ref Trunk - Trunk = object - next: PTrunk # all nodes are connected with this pointer - key: int # start address at bit 0 - bits: array[0..IntsPerTrunk - 1, BitScalar] # a bit vector - - TrunkSeq = seq[PTrunk] - IntSet* = object ## An efficient set of `int` implemented as a sparse bit set. - elems: int # only valid for small numbers - counter, max: int - head: PTrunk - data: TrunkSeq - a: array[0..33, int] # profiling shows that 34 elements are enough - -proc mustRehash[T](t: T): bool {.inline.} = - let length = t.max + 1 - assert length > t.counter - result = (length * 2 < t.counter * 3) or (length - t.counter < 4) - -proc nextTry(h, maxHash: Hash, perturb: var Hash): Hash {.inline.} = - const PERTURB_SHIFT = 5 - var perturb2 = cast[uint](perturb) shr PERTURB_SHIFT - perturb = cast[Hash](perturb2) - result = ((5*h) + 1 + perturb) and maxHash - -proc intSetGet(t: IntSet, key: int): PTrunk = - var h = key and t.max - var perturb = key - while t.data[h] != nil: - if t.data[h].key == key: - return t.data[h] - h = nextTry(h, t.max, perturb) - result = nil - -proc intSetRawInsert(t: IntSet, data: var TrunkSeq, desc: PTrunk) = - var h = desc.key and t.max - var perturb = desc.key - while data[h] != nil: - assert(data[h] != desc) - h = nextTry(h, t.max, perturb) - assert(data[h] == nil) - data[h] = desc - -proc intSetEnlarge(t: var IntSet) = - var n: TrunkSeq - var oldMax = t.max - t.max = ((t.max + 1) * 2) - 1 - newSeq(n, t.max + 1) - for i in countup(0, oldMax): - if t.data[i] != nil: intSetRawInsert(t, n, t.data[i]) - swap(t.data, n) - -proc intSetPut(t: var IntSet, key: int): PTrunk = - var h = key and t.max - var perturb = key - while t.data[h] != nil: - if t.data[h].key == key: - return t.data[h] - h = nextTry(h, t.max, perturb) - if mustRehash(t): intSetEnlarge(t) - inc(t.counter) - h = key and t.max - perturb = key - while t.data[h] != nil: h = nextTry(h, t.max, perturb) - assert(t.data[h] == nil) - new(result) - result.next = t.head - result.key = key - t.head = result - t.data[h] = result - -proc bitincl(s: var IntSet, key: int) {.inline.} = - var ret: PTrunk - var t = intSetPut(s, `shr`(key, TrunkShift)) - var u = key and TrunkMask - t.bits[u shr IntShift] = t.bits[u shr IntShift] or - (BitScalar(1) shl (u and IntMask)) - -proc exclImpl(s: var IntSet, key: int) = - if s.elems <= s.a.len: - for i in 0..<s.elems: - if s.a[i] == key: - s.a[i] = s.a[s.elems-1] - dec s.elems - return - else: - var t = intSetGet(s, key shr TrunkShift) - if t != nil: - var u = key and TrunkMask - t.bits[u shr IntShift] = t.bits[u shr IntShift] and - not(BitScalar(1) shl (u and IntMask)) - -template dollarImpl(): untyped = - result = "{" - for key in items(s): - if result.len > 1: result.add(", ") - result.add($key) - result.add("}") - - -iterator items*(s: IntSet): int {.inline.} = - ## Iterates over any included element of `s`. - if s.elems <= s.a.len: - for i in 0..<s.elems: - yield s.a[i] - else: - var r = s.head - while r != nil: - var i = 0 - while i <= high(r.bits): - var w: uint = r.bits[i] - # taking a copy of r.bits[i] here is correct, because - # modifying operations are not allowed during traversation - var j = 0 - while w != 0: # test all remaining bits for zero - if (w and 1) != 0: # the bit is set! - yield (r.key shl TrunkShift) or (i shl IntShift +% j) - inc(j) - w = w shr 1 - inc(i) - r = r.next - - -proc initIntSet*: IntSet = - ## Returns an empty IntSet. - ## - ## See also: - ## * `toIntSet proc <#toIntSet,openArray[int]>`_ - runnableExamples: - var a = initIntSet() - assert len(a) == 0 - - # newSeq(result.data, InitIntSetSize) - # result.max = InitIntSetSize-1 - result = IntSet( - elems: 0, - counter: 0, - max: 0, - head: nil, - data: when defined(nimNoNilSeqs): @[] else: nil) - # a: array[0..33, int] # profiling shows that 34 elements are enough - -proc contains*(s: IntSet, key: int): bool = - ## Returns true if `key` is in `s`. - ## - ## This allows the usage of `in` operator. - runnableExamples: - var a = initIntSet() - for x in [1, 3, 5]: - a.incl(x) - assert a.contains(3) - assert 3 in a - assert(not a.contains(8)) - assert 8 notin a - - if s.elems <= s.a.len: - for i in 0..<s.elems: - if s.a[i] == key: return true - else: - var t = intSetGet(s, `shr`(key, TrunkShift)) - if t != nil: - var u = key and TrunkMask - result = (t.bits[u shr IntShift] and - (BitScalar(1) shl (u and IntMask))) != 0 - else: - result = false - -proc incl*(s: var IntSet, key: int) = - ## Includes an element `key` in `s`. - ## - ## This doesn't do anything if `key` is already in `s`. - ## - ## See also: - ## * `excl proc <#excl,IntSet,int>`_ for excluding an element - ## * `incl proc <#incl,IntSet,IntSet>`_ for including other set - ## * `containsOrIncl proc <#containsOrIncl,IntSet,int>`_ - runnableExamples: - var a = initIntSet() - a.incl(3) - a.incl(3) - assert len(a) == 1 - - if s.elems <= s.a.len: - for i in 0..<s.elems: - if s.a[i] == key: return - if s.elems < s.a.len: - s.a[s.elems] = key - inc s.elems - return - newSeq(s.data, InitIntSetSize) - s.max = InitIntSetSize-1 - for i in 0..<s.elems: - bitincl(s, s.a[i]) - s.elems = s.a.len + 1 - # fall through: - bitincl(s, key) - -proc incl*(s: var IntSet, other: IntSet) = - ## Includes all elements from `other` into `s`. - ## - ## This is the in-place version of `s + other <#+,IntSet,IntSet>`_. - ## - ## See also: - ## * `excl proc <#excl,IntSet,IntSet>`_ for excluding other set - ## * `incl proc <#incl,IntSet,int>`_ for including an element - ## * `containsOrIncl proc <#containsOrIncl,IntSet,int>`_ - runnableExamples: - var - a = initIntSet() - b = initIntSet() - a.incl(1) - b.incl(5) - a.incl(b) - assert len(a) == 2 - assert 5 in a - - for item in other: incl(s, item) - -proc toIntSet*(x: openArray[int]): IntSet {.since: (1, 3).} = - ## Creates a new IntSet that contains the elements of `x`. - ## - ## Duplicates are removed. - ## - ## See also: - ## * `initIntSet proc <#initIntSet>`_ - runnableExamples: - var - a = toIntSet([5, 6, 7]) - b = toIntSet(@[1, 8, 8, 8]) - assert len(a) == 3 - assert len(b) == 2 - - result = initIntSet() - for item in items(x): - result.incl(item) - -proc containsOrIncl*(s: var IntSet, key: int): bool = - ## Includes `key` in the set `s` and tells if `key` was already in `s`. - ## - ## The difference with regards to the `incl proc <#incl,IntSet,int>`_ is - ## that this proc returns `true` if `s` already contained `key`. The - ## proc will return `false` if `key` was added as a new value to `s` during - ## this call. - ## - ## See also: - ## * `incl proc <#incl,IntSet,int>`_ for including an element - ## * `missingOrExcl proc <#missingOrExcl,IntSet,int>`_ - runnableExamples: - var a = initIntSet() - assert a.containsOrIncl(3) == false - assert a.containsOrIncl(3) == true - assert a.containsOrIncl(4) == false - - if s.elems <= s.a.len: - for i in 0..<s.elems: - if s.a[i] == key: - return true - incl(s, key) - result = false - else: - var t = intSetGet(s, `shr`(key, TrunkShift)) - if t != nil: - var u = key and TrunkMask - result = (t.bits[u shr IntShift] and BitScalar(1) shl (u and IntMask)) != 0 - if not result: - t.bits[u shr IntShift] = t.bits[u shr IntShift] or - (BitScalar(1) shl (u and IntMask)) - else: - incl(s, key) - result = false - -proc excl*(s: var IntSet, key: int) = - ## Excludes `key` from the set `s`. - ## - ## This doesn't do anything if `key` is not found in `s`. - ## - ## See also: - ## * `incl proc <#incl,IntSet,int>`_ for including an element - ## * `excl proc <#excl,IntSet,IntSet>`_ for excluding other set - ## * `missingOrExcl proc <#missingOrExcl,IntSet,int>`_ - runnableExamples: - var a = initIntSet() - a.incl(3) - a.excl(3) - a.excl(3) - a.excl(99) - assert len(a) == 0 - exclImpl(s, key) - -proc excl*(s: var IntSet, other: IntSet) = - ## Excludes all elements from `other` from `s`. - ## - ## This is the in-place version of `s - other <#-,IntSet,IntSet>`_. - ## - ## See also: - ## * `incl proc <#incl,IntSet,IntSet>`_ for including other set - ## * `excl proc <#excl,IntSet,int>`_ for excluding an element - ## * `missingOrExcl proc <#missingOrExcl,IntSet,int>`_ - runnableExamples: - var - a = initIntSet() - b = initIntSet() - a.incl(1) - a.incl(5) - b.incl(5) - a.excl(b) - assert len(a) == 1 - assert 5 notin a - - for item in other: excl(s, item) - -proc len*(s: IntSet): int {.inline.} = - ## Returns the number of elements in `s`. - if s.elems < s.a.len: - result = s.elems - else: - result = 0 - for _ in s: - inc(result) - -proc missingOrExcl*(s: var IntSet, key: int): bool = - ## Excludes `key` in the set `s` and tells if `key` was already missing from `s`. - ## - ## The difference with regards to the `excl proc <#excl,IntSet,int>`_ is - ## that this proc returns `true` if `key` was missing from `s`. - ## The proc will return `false` if `key` was in `s` and it was removed - ## during this call. - ## - ## See also: - ## * `excl proc <#excl,IntSet,int>`_ for excluding an element - ## * `excl proc <#excl,IntSet,IntSet>`_ for excluding other set - ## * `containsOrIncl proc <#containsOrIncl,IntSet,int>`_ - runnableExamples: - var a = initIntSet() - a.incl(5) - assert a.missingOrExcl(5) == false - assert a.missingOrExcl(5) == true - - var count = s.len - exclImpl(s, key) - result = count == s.len - -proc clear*(result: var IntSet) = - ## Clears the IntSet back to an empty state. - runnableExamples: - var a = initIntSet() - a.incl(5) - a.incl(7) - clear(a) - assert len(a) == 0 - - # setLen(result.data, InitIntSetSize) - # for i in 0..InitIntSetSize-1: result.data[i] = nil - # result.max = InitIntSetSize-1 - when defined(nimNoNilSeqs): - result.data = @[] - else: - result.data = nil - result.max = 0 - result.counter = 0 - result.head = nil - result.elems = 0 - -proc isNil*(x: IntSet): bool {.inline.} = x.head.isNil and x.elems == 0 - -proc assign*(dest: var IntSet, src: IntSet) = - ## Copies `src` to `dest`. - ## `dest` does not need to be initialized by `initIntSet proc <#initIntSet>`_. - runnableExamples: - var - a = initIntSet() - b = initIntSet() - b.incl(5) - b.incl(7) - a.assign(b) - assert len(a) == 2 - - if src.elems <= src.a.len: - when defined(nimNoNilSeqs): - dest.data = @[] - else: - dest.data = nil - dest.max = 0 - dest.counter = src.counter - dest.head = nil - dest.elems = src.elems - dest.a = src.a - else: - dest.counter = src.counter - dest.max = src.max - dest.elems = src.elems - newSeq(dest.data, src.data.len) - - var it = src.head - while it != nil: - var h = it.key and dest.max - var perturb = it.key - while dest.data[h] != nil: h = nextTry(h, dest.max, perturb) - assert(dest.data[h] == nil) - var n: PTrunk - new(n) - n.next = dest.head - n.key = it.key - n.bits = it.bits - dest.head = n - dest.data[h] = n - it = it.next - -proc union*(s1, s2: IntSet): IntSet = - ## Returns the union of the sets `s1` and `s2`. - ## - ## The same as `s1 + s2 <#+,IntSet,IntSet>`_. - runnableExamples: - var - a = initIntSet() - b = initIntSet() - a.incl(1); a.incl(2); a.incl(3) - b.incl(3); b.incl(4); b.incl(5) - assert union(a, b).len == 5 - ## {1, 2, 3, 4, 5} - - result.assign(s1) - incl(result, s2) - -proc intersection*(s1, s2: IntSet): IntSet = - ## Returns the intersection of the sets `s1` and `s2`. - ## - ## The same as `s1 * s2 <#*,IntSet,IntSet>`_. - runnableExamples: - var - a = initIntSet() - b = initIntSet() - a.incl(1); a.incl(2); a.incl(3) - b.incl(3); b.incl(4); b.incl(5) - assert intersection(a, b).len == 1 - ## {3} - - result = initIntSet() - for item in s1: - if contains(s2, item): - incl(result, item) - -proc difference*(s1, s2: IntSet): IntSet = - ## Returns the difference of the sets `s1` and `s2`. - ## - ## The same as `s1 - s2 <#-,IntSet,IntSet>`_. - runnableExamples: - var - a = initIntSet() - b = initIntSet() - a.incl(1); a.incl(2); a.incl(3) - b.incl(3); b.incl(4); b.incl(5) - assert difference(a, b).len == 2 - ## {1, 2} - - result = initIntSet() - for item in s1: - if not contains(s2, item): - incl(result, item) - -proc symmetricDifference*(s1, s2: IntSet): IntSet = - ## Returns the symmetric difference of the sets `s1` and `s2`. - runnableExamples: - var - a = initIntSet() - b = initIntSet() - a.incl(1); a.incl(2); a.incl(3) - b.incl(3); b.incl(4); b.incl(5) - assert symmetricDifference(a, b).len == 4 - ## {1, 2, 4, 5} - - result.assign(s1) - for item in s2: - if containsOrIncl(result, item): excl(result, item) - -proc `+`*(s1, s2: IntSet): IntSet {.inline.} = - ## Alias for `union(s1, s2) <#union,IntSet,IntSet>`_. - result = union(s1, s2) - -proc `*`*(s1, s2: IntSet): IntSet {.inline.} = - ## Alias for `intersection(s1, s2) <#intersection,IntSet,IntSet>`_. - result = intersection(s1, s2) - -proc `-`*(s1, s2: IntSet): IntSet {.inline.} = - ## Alias for `difference(s1, s2) <#difference,IntSet,IntSet>`_. - result = difference(s1, s2) - -proc disjoint*(s1, s2: IntSet): bool = - ## Returns true if the sets `s1` and `s2` have no items in common. - runnableExamples: - var - a = initIntSet() - b = initIntSet() - a.incl(1); a.incl(2) - b.incl(2); b.incl(3) - assert disjoint(a, b) == false - b.excl(2) - assert disjoint(a, b) == true - - for item in s1: - if contains(s2, item): - return false - return true - -proc card*(s: IntSet): int {.inline.} = - ## Alias for `len() <#len,IntSet>`_. - result = s.len() - -proc `<=`*(s1, s2: IntSet): bool = - ## Returns true if `s1` is subset of `s2`. - ## - ## A subset `s1` has all of its elements in `s2`, and `s2` doesn't necessarily - ## have more elements than `s1`. That is, `s1` can be equal to `s2`. - runnableExamples: - var - a = initIntSet() - b = initIntSet() - a.incl(1) - b.incl(1); b.incl(2) - assert a <= b - a.incl(2) - assert a <= b - a.incl(3) - assert(not (a <= b)) - - for item in s1: - if not s2.contains(item): - return false - return true - -proc `<`*(s1, s2: IntSet): bool = - ## Returns true if `s1` is proper subset of `s2`. - ## - ## A strict or proper subset `s1` has all of its elements in `s2`, but `s2` has - ## more elements than `s1`. - runnableExamples: - var - a = initIntSet() - b = initIntSet() - a.incl(1) - b.incl(1); b.incl(2) - assert a < b - a.incl(2) - assert(not (a < b)) - return s1 <= s2 and not (s2 <= s1) - -proc `==`*(s1, s2: IntSet): bool = - ## Returns true if both `s1` and `s2` have the same elements and set size. - return s1 <= s2 and s2 <= s1 - -proc `$`*(s: IntSet): string = - ## The `$` operator for int sets. - ## - ## Converts the set `s` to a string, mostly for logging and printing purposes. - dollarImpl() - - - -when isMainModule: - import sequtils, algorithm - - var x = initIntSet() - x.incl(1) - x.incl(2) - x.incl(7) - x.incl(1056) - - x.incl(1044) - x.excl(1044) - - assert x == [1, 2, 7, 1056].toIntSet - - assert x.containsOrIncl(888) == false - assert 888 in x - assert x.containsOrIncl(888) == true - - assert x.missingOrExcl(888) == false - assert 888 notin x - assert x.missingOrExcl(888) == true - - var xs = toSeq(items(x)) - xs.sort(cmp[int]) - assert xs == @[1, 2, 7, 1056] - - var y: IntSet - assign(y, x) - var ys = toSeq(items(y)) - ys.sort(cmp[int]) - assert ys == @[1, 2, 7, 1056] - - assert x == y - - var z: IntSet - for i in 0..1000: - incl z, i - assert z.len() == i+1 - for i in 0..1000: - assert z.contains(i) - - var w = initIntSet() - w.incl(1) - w.incl(4) - w.incl(50) - w.incl(1001) - w.incl(1056) - - var xuw = x.union(w) - var xuws = toSeq(items(xuw)) - xuws.sort(cmp[int]) - assert xuws == @[1, 2, 4, 7, 50, 1001, 1056] - - var xiw = x.intersection(w) - var xiws = toSeq(items(xiw)) - xiws.sort(cmp[int]) - assert xiws == @[1, 1056] - - var xdw = x.difference(w) - var xdws = toSeq(items(xdw)) - xdws.sort(cmp[int]) - assert xdws == @[2, 7] - - var xsw = x.symmetricDifference(w) - var xsws = toSeq(items(xsw)) - xsws.sort(cmp[int]) - assert xsws == @[2, 4, 7, 50, 1001] - - x.incl(w) - xs = toSeq(items(x)) - xs.sort(cmp[int]) - assert xs == @[1, 2, 4, 7, 50, 1001, 1056] - - assert w <= x - - assert w < x - - assert(not disjoint(w, x)) - - var u = initIntSet() - u.incl(3) - u.incl(5) - u.incl(500) - assert disjoint(u, x) - - var v = initIntSet() - v.incl(2) - v.incl(50) - - x.excl(v) - xs = toSeq(items(x)) - xs.sort(cmp[int]) - assert xs == @[1, 4, 7, 1001, 1056] - - proc bug12366 = - var - x = initIntSet() - y = initIntSet() - n = 3584 - - for i in 0..n: - x.incl(i) - y.incl(i) - - let z = symmetricDifference(x, y) - doAssert z.len == 0 - doAssert $z == "{}" +proc initIntSet*(): IntSet {.inline.} = initPackedSet[int]() - bug12366() |