1444 lines
54 KiB
Zig
1444 lines
54 KiB
Zig
//! This file defines several variants of bit sets. A bit set
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//! is a densely stored set of integers with a known maximum,
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//! in which each integer gets a single bit. Bit sets have very
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//! fast presence checks, update operations, and union and intersection
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//! operations. However, if the number of possible items is very
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//! large and the number of actual items in a given set is usually
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//! small, they may be less memory efficient than an array set.
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//!
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//! There are five variants defined here:
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//!
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//! IntegerBitSet:
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//! A bit set with static size, which is backed by a single integer.
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//! This set is good for sets with a small size, but may generate
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//! inefficient code for larger sets, especially in debug mode.
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//!
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//! ArrayBitSet:
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//! A bit set with static size, which is backed by an array of usize.
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//! This set is good for sets with a larger size, but may use
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//! more bytes than necessary if your set is small.
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//!
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//! StaticBitSet:
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//! Picks either IntegerBitSet or ArrayBitSet depending on the requested
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//! size. The interfaces of these two types match exactly, except for fields.
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//!
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//! DynamicBitSet:
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//! A bit set with runtime known size, backed by an allocated slice
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//! of usize.
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//!
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//! DynamicBitSetUnmanaged:
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//! A variant of DynamicBitSet which does not store a pointer to its
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//! allocator, in order to save space.
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const std = @import("std");
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const assert = std.debug.assert;
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const Allocator = std.mem.Allocator;
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/// Returns the optimal static bit set type for the specified number
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/// of elements. The returned type will perform no allocations,
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/// can be copied by value, and does not require deinitialization.
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/// Both possible implementations fulfill the same interface.
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pub fn StaticBitSet(comptime size: usize) type {
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if (size <= @bitSizeOf(usize)) {
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return IntegerBitSet(size);
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} else {
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return ArrayBitSet(usize, size);
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}
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}
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/// A bit set with static size, which is backed by a single integer.
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/// This set is good for sets with a small size, but may generate
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/// inefficient code for larger sets, especially in debug mode.
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pub fn IntegerBitSet(comptime size: u16) type {
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return packed struct {
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const Self = @This();
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// TODO: Make this a comptime field once those are fixed
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/// The number of items in this bit set
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pub const bit_length: usize = size;
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/// The integer type used to represent a mask in this bit set
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pub const MaskInt = std.meta.Int(.unsigned, size);
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/// The integer type used to shift a mask in this bit set
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pub const ShiftInt = std.math.Log2Int(MaskInt);
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/// The bit mask, as a single integer
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mask: MaskInt,
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/// Creates a bit set with no elements present.
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pub fn initEmpty() Self {
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return .{ .mask = 0 };
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}
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/// Creates a bit set with all elements present.
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pub fn initFull() Self {
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return .{ .mask = ~@as(MaskInt, 0) };
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}
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/// Returns the number of bits in this bit set
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pub inline fn capacity(self: Self) usize {
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_ = self;
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return bit_length;
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}
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/// Returns true if the bit at the specified index
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/// is present in the set, false otherwise.
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pub fn isSet(self: Self, index: usize) bool {
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assert(index < bit_length);
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return (self.mask & maskBit(index)) != 0;
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}
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/// Returns the total number of set bits in this bit set.
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pub fn count(self: Self) usize {
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return @popCount(MaskInt, self.mask);
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}
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/// Changes the value of the specified bit of the bit
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/// set to match the passed boolean.
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pub fn setValue(self: *Self, index: usize, value: bool) void {
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assert(index < bit_length);
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if (MaskInt == u0) return;
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const bit = maskBit(index);
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const new_bit = bit & std.math.boolMask(MaskInt, value);
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self.mask = (self.mask & ~bit) | new_bit;
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}
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/// Adds a specific bit to the bit set
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pub fn set(self: *Self, index: usize) void {
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assert(index < bit_length);
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self.mask |= maskBit(index);
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}
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/// Changes the value of all bits in the specified range to
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/// match the passed boolean.
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pub fn setRangeValue(self: *Self, range: Range, value: bool) void {
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assert(range.end <= bit_length);
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assert(range.start <= range.end);
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if (range.start == range.end) return;
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if (MaskInt == u0) return;
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const start_bit = @intCast(ShiftInt, range.start);
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var mask = std.math.boolMask(MaskInt, true) << start_bit;
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if (range.end != bit_length) {
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const end_bit = @intCast(ShiftInt, range.end);
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mask &= std.math.boolMask(MaskInt, true) >> @truncate(ShiftInt, @as(usize, @bitSizeOf(MaskInt)) - @as(usize, end_bit));
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}
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self.mask &= ~mask;
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mask = std.math.boolMask(MaskInt, value) << start_bit;
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if (range.end != bit_length) {
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const end_bit = @intCast(ShiftInt, range.end);
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mask &= std.math.boolMask(MaskInt, value) >> @truncate(ShiftInt, @as(usize, @bitSizeOf(MaskInt)) - @as(usize, end_bit));
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}
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self.mask |= mask;
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}
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/// Removes a specific bit from the bit set
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pub fn unset(self: *Self, index: usize) void {
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assert(index < bit_length);
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// Workaround for #7953
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if (MaskInt == u0) return;
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self.mask &= ~maskBit(index);
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}
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/// Flips a specific bit in the bit set
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pub fn toggle(self: *Self, index: usize) void {
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assert(index < bit_length);
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self.mask ^= maskBit(index);
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}
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/// Flips all bits in this bit set which are present
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/// in the toggles bit set.
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pub fn toggleSet(self: *Self, toggles: Self) void {
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self.mask ^= toggles.mask;
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}
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/// Flips every bit in the bit set.
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pub fn toggleAll(self: *Self) void {
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self.mask = ~self.mask;
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}
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/// Performs a union of two bit sets, and stores the
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/// result in the first one. Bits in the result are
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/// set if the corresponding bits were set in either input.
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pub fn setUnion(self: *Self, other: Self) void {
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self.mask |= other.mask;
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}
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/// Performs an intersection of two bit sets, and stores
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/// the result in the first one. Bits in the result are
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/// set if the corresponding bits were set in both inputs.
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pub fn setIntersection(self: *Self, other: Self) void {
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self.mask &= other.mask;
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}
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/// Finds the index of the first set bit.
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/// If no bits are set, returns null.
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pub fn findFirstSet(self: Self) ?usize {
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const mask = self.mask;
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if (mask == 0) return null;
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return @ctz(MaskInt, mask);
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}
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/// Finds the index of the first set bit, and unsets it.
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/// If no bits are set, returns null.
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pub fn toggleFirstSet(self: *Self) ?usize {
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const mask = self.mask;
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if (mask == 0) return null;
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const index = @ctz(MaskInt, mask);
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self.mask = mask & (mask - 1);
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return index;
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}
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/// Iterates through the items in the set, according to the options.
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/// The default options (.{}) will iterate indices of set bits in
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/// ascending order. Modifications to the underlying bit set may
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/// or may not be observed by the iterator.
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pub fn iterator(self: *const Self, comptime options: IteratorOptions) Iterator(options) {
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return .{
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.bits_remain = switch (options.kind) {
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.set => self.mask,
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.unset => ~self.mask,
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},
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};
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}
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pub fn Iterator(comptime options: IteratorOptions) type {
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return SingleWordIterator(options.direction);
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}
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fn SingleWordIterator(comptime direction: IteratorOptions.Direction) type {
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return struct {
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const IterSelf = @This();
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// all bits which have not yet been iterated over
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bits_remain: MaskInt,
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/// Returns the index of the next unvisited set bit
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/// in the bit set, in ascending order.
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pub fn next(self: *IterSelf) ?usize {
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if (self.bits_remain == 0) return null;
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switch (direction) {
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.forward => {
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const next_index = @ctz(MaskInt, self.bits_remain);
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self.bits_remain &= self.bits_remain - 1;
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return next_index;
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},
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.reverse => {
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const leading_zeroes = @clz(MaskInt, self.bits_remain);
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const top_bit = (@bitSizeOf(MaskInt) - 1) - leading_zeroes;
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self.bits_remain &= (@as(MaskInt, 1) << @intCast(ShiftInt, top_bit)) - 1;
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return top_bit;
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},
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}
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}
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};
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}
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fn maskBit(index: usize) MaskInt {
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if (MaskInt == u0) return 0;
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return @as(MaskInt, 1) << @intCast(ShiftInt, index);
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}
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fn boolMaskBit(index: usize, value: bool) MaskInt {
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if (MaskInt == u0) return 0;
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return @as(MaskInt, @boolToInt(value)) << @intCast(ShiftInt, index);
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}
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};
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}
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/// A bit set with static size, which is backed by an array of usize.
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/// This set is good for sets with a larger size, but may use
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/// more bytes than necessary if your set is small.
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pub fn ArrayBitSet(comptime MaskIntType: type, comptime size: usize) type {
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const mask_info: std.builtin.Type = @typeInfo(MaskIntType);
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// Make sure the mask int is indeed an int
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if (mask_info != .Int) @compileError("ArrayBitSet can only operate on integer masks, but was passed " ++ @typeName(MaskIntType));
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// It must also be unsigned.
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if (mask_info.Int.signedness != .unsigned) @compileError("ArrayBitSet requires an unsigned integer mask type, but was passed " ++ @typeName(MaskIntType));
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// And it must not be empty.
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if (MaskIntType == u0)
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@compileError("ArrayBitSet requires a sized integer for its mask int. u0 does not work.");
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const byte_size = std.mem.byte_size_in_bits;
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// We use shift and truncate to decompose indices into mask indices and bit indices.
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// This operation requires that the mask has an exact power of two number of bits.
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if (!std.math.isPowerOfTwo(@bitSizeOf(MaskIntType))) {
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var desired_bits = std.math.ceilPowerOfTwoAssert(usize, @bitSizeOf(MaskIntType));
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if (desired_bits < byte_size) desired_bits = byte_size;
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const FixedMaskType = std.meta.Int(.unsigned, desired_bits);
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@compileError("ArrayBitSet was passed integer type " ++ @typeName(MaskIntType) ++
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", which is not a power of two. Please round this up to a power of two integer size (i.e. " ++ @typeName(FixedMaskType) ++ ").");
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}
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// Make sure the integer has no padding bits.
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// Those would be wasteful here and are probably a mistake by the user.
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// This case may be hit with small powers of two, like u4.
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if (@bitSizeOf(MaskIntType) != @sizeOf(MaskIntType) * byte_size) {
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var desired_bits = @sizeOf(MaskIntType) * byte_size;
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desired_bits = std.math.ceilPowerOfTwoAssert(usize, desired_bits);
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const FixedMaskType = std.meta.Int(.unsigned, desired_bits);
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@compileError("ArrayBitSet was passed integer type " ++ @typeName(MaskIntType) ++
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", which contains padding bits. Please round this up to an unpadded integer size (i.e. " ++ @typeName(FixedMaskType) ++ ").");
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}
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return extern struct {
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const Self = @This();
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// TODO: Make this a comptime field once those are fixed
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/// The number of items in this bit set
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pub const bit_length: usize = size;
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/// The integer type used to represent a mask in this bit set
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pub const MaskInt = MaskIntType;
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/// The integer type used to shift a mask in this bit set
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pub const ShiftInt = std.math.Log2Int(MaskInt);
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// bits in one mask
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const mask_len = @bitSizeOf(MaskInt);
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// total number of masks
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const num_masks = (size + mask_len - 1) / mask_len;
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// padding bits in the last mask (may be 0)
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const last_pad_bits = mask_len * num_masks - size;
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// Mask of valid bits in the last mask.
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// All functions will ensure that the invalid
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// bits in the last mask are zero.
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pub const last_item_mask = ~@as(MaskInt, 0) >> last_pad_bits;
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/// The bit masks, ordered with lower indices first.
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/// Padding bits at the end are undefined.
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masks: [num_masks]MaskInt,
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/// Creates a bit set with no elements present.
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pub fn initEmpty() Self {
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return .{ .masks = [_]MaskInt{0} ** num_masks };
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}
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/// Creates a bit set with all elements present.
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pub fn initFull() Self {
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if (num_masks == 0) {
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return .{ .masks = .{} };
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} else {
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return .{ .masks = [_]MaskInt{~@as(MaskInt, 0)} ** (num_masks - 1) ++ [_]MaskInt{last_item_mask} };
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}
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}
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/// Returns the number of bits in this bit set
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pub inline fn capacity(self: Self) usize {
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_ = self;
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return bit_length;
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}
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/// Returns true if the bit at the specified index
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/// is present in the set, false otherwise.
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pub fn isSet(self: Self, index: usize) bool {
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assert(index < bit_length);
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if (num_masks == 0) return false; // doesn't compile in this case
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return (self.masks[maskIndex(index)] & maskBit(index)) != 0;
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}
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/// Returns the total number of set bits in this bit set.
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pub fn count(self: Self) usize {
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var total: usize = 0;
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for (self.masks) |mask| {
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total += @popCount(MaskInt, mask);
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}
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return total;
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}
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/// Changes the value of the specified bit of the bit
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/// set to match the passed boolean.
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pub fn setValue(self: *Self, index: usize, value: bool) void {
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assert(index < bit_length);
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if (num_masks == 0) return; // doesn't compile in this case
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const bit = maskBit(index);
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const mask_index = maskIndex(index);
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const new_bit = bit & std.math.boolMask(MaskInt, value);
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self.masks[mask_index] = (self.masks[mask_index] & ~bit) | new_bit;
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}
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/// Adds a specific bit to the bit set
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pub fn set(self: *Self, index: usize) void {
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assert(index < bit_length);
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if (num_masks == 0) return; // doesn't compile in this case
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self.masks[maskIndex(index)] |= maskBit(index);
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}
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/// Changes the value of all bits in the specified range to
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/// match the passed boolean.
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pub fn setRangeValue(self: *Self, range: Range, value: bool) void {
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assert(range.end <= bit_length);
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assert(range.start <= range.end);
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if (range.start == range.end) return;
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if (num_masks == 0) return;
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const start_mask_index = maskIndex(range.start);
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const start_bit = @truncate(ShiftInt, range.start);
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const end_mask_index = maskIndex(range.end);
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const end_bit = @truncate(ShiftInt, range.end);
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if (start_mask_index == end_mask_index) {
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var mask1 = std.math.boolMask(MaskInt, true) << start_bit;
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var mask2 = std.math.boolMask(MaskInt, true) >> (mask_len - 1) - (end_bit - 1);
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self.masks[start_mask_index] &= ~(mask1 & mask2);
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mask1 = std.math.boolMask(MaskInt, value) << start_bit;
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mask2 = std.math.boolMask(MaskInt, value) >> (mask_len - 1) - (end_bit - 1);
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self.masks[start_mask_index] |= mask1 & mask2;
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} else {
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var bulk_mask_index: usize = undefined;
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if (start_bit > 0) {
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self.masks[start_mask_index] =
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(self.masks[start_mask_index] & ~(std.math.boolMask(MaskInt, true) << start_bit)) |
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(std.math.boolMask(MaskInt, value) << start_bit);
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bulk_mask_index = start_mask_index + 1;
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} else {
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bulk_mask_index = start_mask_index;
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}
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while (bulk_mask_index < end_mask_index) : (bulk_mask_index += 1) {
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self.masks[bulk_mask_index] = std.math.boolMask(MaskInt, value);
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}
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if (end_bit > 0) {
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self.masks[end_mask_index] =
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(self.masks[end_mask_index] & (std.math.boolMask(MaskInt, true) << end_bit)) |
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(std.math.boolMask(MaskInt, value) >> ((@bitSizeOf(MaskInt) - 1) - (end_bit - 1)));
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}
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}
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}
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/// Removes a specific bit from the bit set
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pub fn unset(self: *Self, index: usize) void {
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assert(index < bit_length);
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if (num_masks == 0) return; // doesn't compile in this case
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self.masks[maskIndex(index)] &= ~maskBit(index);
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}
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/// Flips a specific bit in the bit set
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pub fn toggle(self: *Self, index: usize) void {
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assert(index < bit_length);
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if (num_masks == 0) return; // doesn't compile in this case
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self.masks[maskIndex(index)] ^= maskBit(index);
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}
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/// Flips all bits in this bit set which are present
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/// in the toggles bit set.
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pub fn toggleSet(self: *Self, toggles: Self) void {
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for (self.masks) |*mask, i| {
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mask.* ^= toggles.masks[i];
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}
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}
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/// Flips every bit in the bit set.
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pub fn toggleAll(self: *Self) void {
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for (self.masks) |*mask| {
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mask.* = ~mask.*;
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}
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// Zero the padding bits
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if (num_masks > 0) {
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self.masks[num_masks - 1] &= last_item_mask;
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}
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}
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|
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/// Performs a union of two bit sets, and stores the
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/// result in the first one. Bits in the result are
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/// set if the corresponding bits were set in either input.
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pub fn setUnion(self: *Self, other: Self) void {
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for (self.masks) |*mask, i| {
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mask.* |= other.masks[i];
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}
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}
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|
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/// Performs an intersection of two bit sets, and stores
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/// the result in the first one. Bits in the result are
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/// set if the corresponding bits were set in both inputs.
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|
pub fn setIntersection(self: *Self, other: Self) void {
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for (self.masks) |*mask, i| {
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mask.* &= other.masks[i];
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}
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}
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|
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/// Finds the index of the first set bit.
|
|
/// If no bits are set, returns null.
|
|
pub fn findFirstSet(self: Self) ?usize {
|
|
var offset: usize = 0;
|
|
const mask = for (self.masks) |mask| {
|
|
if (mask != 0) break mask;
|
|
offset += @bitSizeOf(MaskInt);
|
|
} else return null;
|
|
return offset + @ctz(MaskInt, mask);
|
|
}
|
|
|
|
/// Finds the index of the first set bit, and unsets it.
|
|
/// If no bits are set, returns null.
|
|
pub fn toggleFirstSet(self: *Self) ?usize {
|
|
var offset: usize = 0;
|
|
const mask = for (self.masks) |*mask| {
|
|
if (mask.* != 0) break mask;
|
|
offset += @bitSizeOf(MaskInt);
|
|
} else return null;
|
|
const index = @ctz(MaskInt, mask.*);
|
|
mask.* &= (mask.* - 1);
|
|
return offset + index;
|
|
}
|
|
|
|
/// Iterates through the items in the set, according to the options.
|
|
/// The default options (.{}) will iterate indices of set bits in
|
|
/// ascending order. Modifications to the underlying bit set may
|
|
/// or may not be observed by the iterator.
|
|
pub fn iterator(self: *const Self, comptime options: IteratorOptions) Iterator(options) {
|
|
return Iterator(options).init(&self.masks, last_item_mask);
|
|
}
|
|
|
|
pub fn Iterator(comptime options: IteratorOptions) type {
|
|
return BitSetIterator(MaskInt, options);
|
|
}
|
|
|
|
fn maskBit(index: usize) MaskInt {
|
|
return @as(MaskInt, 1) << @truncate(ShiftInt, index);
|
|
}
|
|
fn maskIndex(index: usize) usize {
|
|
return index >> @bitSizeOf(ShiftInt);
|
|
}
|
|
fn boolMaskBit(index: usize, value: bool) MaskInt {
|
|
return @as(MaskInt, @boolToInt(value)) << @intCast(ShiftInt, index);
|
|
}
|
|
};
|
|
}
|
|
|
|
/// A bit set with runtime known size, backed by an allocated slice
|
|
/// of usize. The allocator must be tracked externally by the user.
|
|
pub const DynamicBitSetUnmanaged = struct {
|
|
const Self = @This();
|
|
|
|
/// The integer type used to represent a mask in this bit set
|
|
pub const MaskInt = usize;
|
|
|
|
/// The integer type used to shift a mask in this bit set
|
|
pub const ShiftInt = std.math.Log2Int(MaskInt);
|
|
|
|
/// The number of valid items in this bit set
|
|
bit_length: usize = 0,
|
|
|
|
/// The bit masks, ordered with lower indices first.
|
|
/// Padding bits at the end must be zeroed.
|
|
masks: [*]MaskInt = empty_masks_ptr,
|
|
// This pointer is one usize after the actual allocation.
|
|
// That slot holds the size of the true allocation, which
|
|
// is needed by Zig's allocator interface in case a shrink
|
|
// fails.
|
|
|
|
// Don't modify this value. Ideally it would go in const data so
|
|
// modifications would cause a bus error, but the only way
|
|
// to discard a const qualifier is through ptrToInt, which
|
|
// cannot currently round trip at comptime.
|
|
var empty_masks_data = [_]MaskInt{ 0, undefined };
|
|
const empty_masks_ptr = empty_masks_data[1..2];
|
|
|
|
/// Creates a bit set with no elements present.
|
|
/// If bit_length is not zero, deinit must eventually be called.
|
|
pub fn initEmpty(allocator: Allocator, bit_length: usize) !Self {
|
|
var self = Self{};
|
|
try self.resize(allocator, bit_length, false);
|
|
return self;
|
|
}
|
|
|
|
/// Creates a bit set with all elements present.
|
|
/// If bit_length is not zero, deinit must eventually be called.
|
|
pub fn initFull(allocator: Allocator, bit_length: usize) !Self {
|
|
var self = Self{};
|
|
try self.resize(allocator, bit_length, true);
|
|
return self;
|
|
}
|
|
|
|
/// Resizes to a new bit_length. If the new length is larger
|
|
/// than the old length, fills any added bits with `fill`.
|
|
/// If new_len is not zero, deinit must eventually be called.
|
|
pub fn resize(self: *@This(), allocator: Allocator, new_len: usize, fill: bool) !void {
|
|
const old_len = self.bit_length;
|
|
|
|
const old_masks = numMasks(old_len);
|
|
const new_masks = numMasks(new_len);
|
|
|
|
const old_allocation = (self.masks - 1)[0..(self.masks - 1)[0]];
|
|
|
|
if (new_masks == 0) {
|
|
assert(new_len == 0);
|
|
allocator.free(old_allocation);
|
|
self.masks = empty_masks_ptr;
|
|
self.bit_length = 0;
|
|
return;
|
|
}
|
|
|
|
if (old_allocation.len != new_masks + 1) realloc: {
|
|
// If realloc fails, it may mean one of two things.
|
|
// If we are growing, it means we are out of memory.
|
|
// If we are shrinking, it means the allocator doesn't
|
|
// want to move the allocation. This means we need to
|
|
// hold on to the extra 8 bytes required to be able to free
|
|
// this allocation properly.
|
|
const new_allocation = allocator.realloc(old_allocation, new_masks + 1) catch |err| {
|
|
if (new_masks + 1 > old_allocation.len) return err;
|
|
break :realloc;
|
|
};
|
|
|
|
new_allocation[0] = new_allocation.len;
|
|
self.masks = new_allocation.ptr + 1;
|
|
}
|
|
|
|
// If we increased in size, we need to set any new bits
|
|
// to the fill value.
|
|
if (new_len > old_len) {
|
|
// set the padding bits in the old last item to 1
|
|
if (fill and old_masks > 0) {
|
|
const old_padding_bits = old_masks * @bitSizeOf(MaskInt) - old_len;
|
|
const old_mask = (~@as(MaskInt, 0)) >> @intCast(ShiftInt, old_padding_bits);
|
|
self.masks[old_masks - 1] |= ~old_mask;
|
|
}
|
|
|
|
// fill in any new masks
|
|
if (new_masks > old_masks) {
|
|
const fill_value = std.math.boolMask(MaskInt, fill);
|
|
std.mem.set(MaskInt, self.masks[old_masks..new_masks], fill_value);
|
|
}
|
|
}
|
|
|
|
// Zero out the padding bits
|
|
if (new_len > 0) {
|
|
const padding_bits = new_masks * @bitSizeOf(MaskInt) - new_len;
|
|
const last_item_mask = (~@as(MaskInt, 0)) >> @intCast(ShiftInt, padding_bits);
|
|
self.masks[new_masks - 1] &= last_item_mask;
|
|
}
|
|
|
|
// And finally, save the new length.
|
|
self.bit_length = new_len;
|
|
}
|
|
|
|
/// deinitializes the array and releases its memory.
|
|
/// The passed allocator must be the same one used for
|
|
/// init* or resize in the past.
|
|
pub fn deinit(self: *Self, allocator: Allocator) void {
|
|
self.resize(allocator, 0, false) catch unreachable;
|
|
}
|
|
|
|
/// Creates a duplicate of this bit set, using the new allocator.
|
|
pub fn clone(self: *const Self, new_allocator: Allocator) !Self {
|
|
const num_masks = numMasks(self.bit_length);
|
|
var copy = Self{};
|
|
try copy.resize(new_allocator, self.bit_length, false);
|
|
std.mem.copy(MaskInt, copy.masks[0..num_masks], self.masks[0..num_masks]);
|
|
return copy;
|
|
}
|
|
|
|
/// Returns the number of bits in this bit set
|
|
pub inline fn capacity(self: Self) usize {
|
|
return self.bit_length;
|
|
}
|
|
|
|
/// Returns true if the bit at the specified index
|
|
/// is present in the set, false otherwise.
|
|
pub fn isSet(self: Self, index: usize) bool {
|
|
assert(index < self.bit_length);
|
|
return (self.masks[maskIndex(index)] & maskBit(index)) != 0;
|
|
}
|
|
|
|
/// Returns the total number of set bits in this bit set.
|
|
pub fn count(self: Self) usize {
|
|
const num_masks = (self.bit_length + (@bitSizeOf(MaskInt) - 1)) / @bitSizeOf(MaskInt);
|
|
var total: usize = 0;
|
|
for (self.masks[0..num_masks]) |mask| {
|
|
// Note: This is where we depend on padding bits being zero
|
|
total += @popCount(MaskInt, mask);
|
|
}
|
|
return total;
|
|
}
|
|
|
|
/// Changes the value of the specified bit of the bit
|
|
/// set to match the passed boolean.
|
|
pub fn setValue(self: *Self, index: usize, value: bool) void {
|
|
assert(index < self.bit_length);
|
|
const bit = maskBit(index);
|
|
const mask_index = maskIndex(index);
|
|
const new_bit = bit & std.math.boolMask(MaskInt, value);
|
|
self.masks[mask_index] = (self.masks[mask_index] & ~bit) | new_bit;
|
|
}
|
|
|
|
/// Adds a specific bit to the bit set
|
|
pub fn set(self: *Self, index: usize) void {
|
|
assert(index < self.bit_length);
|
|
self.masks[maskIndex(index)] |= maskBit(index);
|
|
}
|
|
|
|
/// Changes the value of all bits in the specified range to
|
|
/// match the passed boolean.
|
|
pub fn setRangeValue(self: *Self, range: Range, value: bool) void {
|
|
assert(range.end <= self.bit_length);
|
|
assert(range.start <= range.end);
|
|
if (range.start == range.end) return;
|
|
|
|
const start_mask_index = maskIndex(range.start);
|
|
const start_bit = @truncate(ShiftInt, range.start);
|
|
|
|
const end_mask_index = maskIndex(range.end);
|
|
const end_bit = @truncate(ShiftInt, range.end);
|
|
|
|
if (start_mask_index == end_mask_index) {
|
|
var mask1 = std.math.boolMask(MaskInt, true) << start_bit;
|
|
var mask2 = std.math.boolMask(MaskInt, true) >> (@bitSizeOf(MaskInt) - 1) - (end_bit - 1);
|
|
self.masks[start_mask_index] &= ~(mask1 & mask2);
|
|
|
|
mask1 = std.math.boolMask(MaskInt, value) << start_bit;
|
|
mask2 = std.math.boolMask(MaskInt, value) >> (@bitSizeOf(MaskInt) - 1) - (end_bit - 1);
|
|
self.masks[start_mask_index] |= mask1 & mask2;
|
|
} else {
|
|
var bulk_mask_index: usize = undefined;
|
|
if (start_bit > 0) {
|
|
self.masks[start_mask_index] =
|
|
(self.masks[start_mask_index] & ~(std.math.boolMask(MaskInt, true) << start_bit)) |
|
|
(std.math.boolMask(MaskInt, value) << start_bit);
|
|
bulk_mask_index = start_mask_index + 1;
|
|
} else {
|
|
bulk_mask_index = start_mask_index;
|
|
}
|
|
|
|
while (bulk_mask_index < end_mask_index) : (bulk_mask_index += 1) {
|
|
self.masks[bulk_mask_index] = std.math.boolMask(MaskInt, value);
|
|
}
|
|
|
|
if (end_bit > 0) {
|
|
self.masks[end_mask_index] =
|
|
(self.masks[end_mask_index] & (std.math.boolMask(MaskInt, true) << end_bit)) |
|
|
(std.math.boolMask(MaskInt, value) >> ((@bitSizeOf(MaskInt) - 1) - (end_bit - 1)));
|
|
}
|
|
}
|
|
}
|
|
|
|
/// Removes a specific bit from the bit set
|
|
pub fn unset(self: *Self, index: usize) void {
|
|
assert(index < self.bit_length);
|
|
self.masks[maskIndex(index)] &= ~maskBit(index);
|
|
}
|
|
|
|
/// Flips a specific bit in the bit set
|
|
pub fn toggle(self: *Self, index: usize) void {
|
|
assert(index < self.bit_length);
|
|
self.masks[maskIndex(index)] ^= maskBit(index);
|
|
}
|
|
|
|
/// Flips all bits in this bit set which are present
|
|
/// in the toggles bit set. Both sets must have the
|
|
/// same bit_length.
|
|
pub fn toggleSet(self: *Self, toggles: Self) void {
|
|
assert(toggles.bit_length == self.bit_length);
|
|
const num_masks = numMasks(self.bit_length);
|
|
for (self.masks[0..num_masks]) |*mask, i| {
|
|
mask.* ^= toggles.masks[i];
|
|
}
|
|
}
|
|
|
|
/// Flips every bit in the bit set.
|
|
pub fn toggleAll(self: *Self) void {
|
|
const bit_length = self.bit_length;
|
|
// avoid underflow if bit_length is zero
|
|
if (bit_length == 0) return;
|
|
|
|
const num_masks = numMasks(self.bit_length);
|
|
for (self.masks[0..num_masks]) |*mask| {
|
|
mask.* = ~mask.*;
|
|
}
|
|
|
|
const padding_bits = num_masks * @bitSizeOf(MaskInt) - bit_length;
|
|
const last_item_mask = (~@as(MaskInt, 0)) >> @intCast(ShiftInt, padding_bits);
|
|
self.masks[num_masks - 1] &= last_item_mask;
|
|
}
|
|
|
|
/// Performs a union of two bit sets, and stores the
|
|
/// result in the first one. Bits in the result are
|
|
/// set if the corresponding bits were set in either input.
|
|
/// The two sets must both be the same bit_length.
|
|
pub fn setUnion(self: *Self, other: Self) void {
|
|
assert(other.bit_length == self.bit_length);
|
|
const num_masks = numMasks(self.bit_length);
|
|
for (self.masks[0..num_masks]) |*mask, i| {
|
|
mask.* |= other.masks[i];
|
|
}
|
|
}
|
|
|
|
/// Performs an intersection of two bit sets, and stores
|
|
/// the result in the first one. Bits in the result are
|
|
/// set if the corresponding bits were set in both inputs.
|
|
/// The two sets must both be the same bit_length.
|
|
pub fn setIntersection(self: *Self, other: Self) void {
|
|
assert(other.bit_length == self.bit_length);
|
|
const num_masks = numMasks(self.bit_length);
|
|
for (self.masks[0..num_masks]) |*mask, i| {
|
|
mask.* &= other.masks[i];
|
|
}
|
|
}
|
|
|
|
/// Finds the index of the first set bit.
|
|
/// If no bits are set, returns null.
|
|
pub fn findFirstSet(self: Self) ?usize {
|
|
var offset: usize = 0;
|
|
var mask = self.masks;
|
|
while (offset < self.bit_length) {
|
|
if (mask[0] != 0) break;
|
|
mask += 1;
|
|
offset += @bitSizeOf(MaskInt);
|
|
} else return null;
|
|
return offset + @ctz(MaskInt, mask[0]);
|
|
}
|
|
|
|
/// Finds the index of the first set bit, and unsets it.
|
|
/// If no bits are set, returns null.
|
|
pub fn toggleFirstSet(self: *Self) ?usize {
|
|
var offset: usize = 0;
|
|
var mask = self.masks;
|
|
while (offset < self.bit_length) {
|
|
if (mask[0] != 0) break;
|
|
mask += 1;
|
|
offset += @bitSizeOf(MaskInt);
|
|
} else return null;
|
|
const index = @ctz(MaskInt, mask[0]);
|
|
mask[0] &= (mask[0] - 1);
|
|
return offset + index;
|
|
}
|
|
|
|
/// Iterates through the items in the set, according to the options.
|
|
/// The default options (.{}) will iterate indices of set bits in
|
|
/// ascending order. Modifications to the underlying bit set may
|
|
/// or may not be observed by the iterator. Resizing the underlying
|
|
/// bit set invalidates the iterator.
|
|
pub fn iterator(self: *const Self, comptime options: IteratorOptions) Iterator(options) {
|
|
const num_masks = numMasks(self.bit_length);
|
|
const padding_bits = num_masks * @bitSizeOf(MaskInt) - self.bit_length;
|
|
const last_item_mask = (~@as(MaskInt, 0)) >> @intCast(ShiftInt, padding_bits);
|
|
return Iterator(options).init(self.masks[0..num_masks], last_item_mask);
|
|
}
|
|
|
|
pub fn Iterator(comptime options: IteratorOptions) type {
|
|
return BitSetIterator(MaskInt, options);
|
|
}
|
|
|
|
fn maskBit(index: usize) MaskInt {
|
|
return @as(MaskInt, 1) << @truncate(ShiftInt, index);
|
|
}
|
|
fn maskIndex(index: usize) usize {
|
|
return index >> @bitSizeOf(ShiftInt);
|
|
}
|
|
fn boolMaskBit(index: usize, value: bool) MaskInt {
|
|
return @as(MaskInt, @boolToInt(value)) << @intCast(ShiftInt, index);
|
|
}
|
|
fn numMasks(bit_length: usize) usize {
|
|
return (bit_length + (@bitSizeOf(MaskInt) - 1)) / @bitSizeOf(MaskInt);
|
|
}
|
|
};
|
|
|
|
/// A bit set with runtime known size, backed by an allocated slice
|
|
/// of usize. Thin wrapper around DynamicBitSetUnmanaged which keeps
|
|
/// track of the allocator instance.
|
|
pub const DynamicBitSet = struct {
|
|
const Self = @This();
|
|
|
|
/// The integer type used to represent a mask in this bit set
|
|
pub const MaskInt = usize;
|
|
|
|
/// The integer type used to shift a mask in this bit set
|
|
pub const ShiftInt = std.math.Log2Int(MaskInt);
|
|
|
|
/// The allocator used by this bit set
|
|
allocator: Allocator,
|
|
|
|
/// The number of valid items in this bit set
|
|
unmanaged: DynamicBitSetUnmanaged = .{},
|
|
|
|
/// Creates a bit set with no elements present.
|
|
pub fn initEmpty(allocator: Allocator, bit_length: usize) !Self {
|
|
return Self{
|
|
.unmanaged = try DynamicBitSetUnmanaged.initEmpty(allocator, bit_length),
|
|
.allocator = allocator,
|
|
};
|
|
}
|
|
|
|
/// Creates a bit set with all elements present.
|
|
pub fn initFull(allocator: Allocator, bit_length: usize) !Self {
|
|
return Self{
|
|
.unmanaged = try DynamicBitSetUnmanaged.initFull(allocator, bit_length),
|
|
.allocator = allocator,
|
|
};
|
|
}
|
|
|
|
/// Resizes to a new length. If the new length is larger
|
|
/// than the old length, fills any added bits with `fill`.
|
|
pub fn resize(self: *@This(), new_len: usize, fill: bool) !void {
|
|
try self.unmanaged.resize(self.allocator, new_len, fill);
|
|
}
|
|
|
|
/// deinitializes the array and releases its memory.
|
|
/// The passed allocator must be the same one used for
|
|
/// init* or resize in the past.
|
|
pub fn deinit(self: *Self) void {
|
|
self.unmanaged.deinit(self.allocator);
|
|
}
|
|
|
|
/// Creates a duplicate of this bit set, using the new allocator.
|
|
pub fn clone(self: *const Self, new_allocator: Allocator) !Self {
|
|
return Self{
|
|
.unmanaged = try self.unmanaged.clone(new_allocator),
|
|
.allocator = new_allocator,
|
|
};
|
|
}
|
|
|
|
/// Returns the number of bits in this bit set
|
|
pub inline fn capacity(self: Self) usize {
|
|
return self.unmanaged.capacity();
|
|
}
|
|
|
|
/// Returns true if the bit at the specified index
|
|
/// is present in the set, false otherwise.
|
|
pub fn isSet(self: Self, index: usize) bool {
|
|
return self.unmanaged.isSet(index);
|
|
}
|
|
|
|
/// Returns the total number of set bits in this bit set.
|
|
pub fn count(self: Self) usize {
|
|
return self.unmanaged.count();
|
|
}
|
|
|
|
/// Changes the value of the specified bit of the bit
|
|
/// set to match the passed boolean.
|
|
pub fn setValue(self: *Self, index: usize, value: bool) void {
|
|
self.unmanaged.setValue(index, value);
|
|
}
|
|
|
|
/// Adds a specific bit to the bit set
|
|
pub fn set(self: *Self, index: usize) void {
|
|
self.unmanaged.set(index);
|
|
}
|
|
|
|
/// Changes the value of all bits in the specified range to
|
|
/// match the passed boolean.
|
|
pub fn setRangeValue(self: *Self, range: Range, value: bool) void {
|
|
self.unmanaged.setRangeValue(range, value);
|
|
}
|
|
|
|
/// Removes a specific bit from the bit set
|
|
pub fn unset(self: *Self, index: usize) void {
|
|
self.unmanaged.unset(index);
|
|
}
|
|
|
|
/// Flips a specific bit in the bit set
|
|
pub fn toggle(self: *Self, index: usize) void {
|
|
self.unmanaged.toggle(index);
|
|
}
|
|
|
|
/// Flips all bits in this bit set which are present
|
|
/// in the toggles bit set. Both sets must have the
|
|
/// same bit_length.
|
|
pub fn toggleSet(self: *Self, toggles: Self) void {
|
|
self.unmanaged.toggleSet(toggles.unmanaged);
|
|
}
|
|
|
|
/// Flips every bit in the bit set.
|
|
pub fn toggleAll(self: *Self) void {
|
|
self.unmanaged.toggleAll();
|
|
}
|
|
|
|
/// Performs a union of two bit sets, and stores the
|
|
/// result in the first one. Bits in the result are
|
|
/// set if the corresponding bits were set in either input.
|
|
/// The two sets must both be the same bit_length.
|
|
pub fn setUnion(self: *Self, other: Self) void {
|
|
self.unmanaged.setUnion(other.unmanaged);
|
|
}
|
|
|
|
/// Performs an intersection of two bit sets, and stores
|
|
/// the result in the first one. Bits in the result are
|
|
/// set if the corresponding bits were set in both inputs.
|
|
/// The two sets must both be the same bit_length.
|
|
pub fn setIntersection(self: *Self, other: Self) void {
|
|
self.unmanaged.setIntersection(other.unmanaged);
|
|
}
|
|
|
|
/// Finds the index of the first set bit.
|
|
/// If no bits are set, returns null.
|
|
pub fn findFirstSet(self: Self) ?usize {
|
|
return self.unmanaged.findFirstSet();
|
|
}
|
|
|
|
/// Finds the index of the first set bit, and unsets it.
|
|
/// If no bits are set, returns null.
|
|
pub fn toggleFirstSet(self: *Self) ?usize {
|
|
return self.unmanaged.toggleFirstSet();
|
|
}
|
|
|
|
/// Iterates through the items in the set, according to the options.
|
|
/// The default options (.{}) will iterate indices of set bits in
|
|
/// ascending order. Modifications to the underlying bit set may
|
|
/// or may not be observed by the iterator. Resizing the underlying
|
|
/// bit set invalidates the iterator.
|
|
pub fn iterator(self: *const Self, comptime options: IteratorOptions) Iterator(options) {
|
|
return self.unmanaged.iterator(options);
|
|
}
|
|
|
|
pub const Iterator = DynamicBitSetUnmanaged.Iterator;
|
|
};
|
|
|
|
/// Options for configuring an iterator over a bit set
|
|
pub const IteratorOptions = struct {
|
|
/// determines which bits should be visited
|
|
kind: Type = .set,
|
|
/// determines the order in which bit indices should be visited
|
|
direction: Direction = .forward,
|
|
|
|
pub const Type = enum {
|
|
/// visit indexes of set bits
|
|
set,
|
|
/// visit indexes of unset bits
|
|
unset,
|
|
};
|
|
|
|
pub const Direction = enum {
|
|
/// visit indices in ascending order
|
|
forward,
|
|
/// visit indices in descending order.
|
|
/// Note that this may be slightly more expensive than forward iteration.
|
|
reverse,
|
|
};
|
|
};
|
|
|
|
// The iterator is reusable between several bit set types
|
|
fn BitSetIterator(comptime MaskInt: type, comptime options: IteratorOptions) type {
|
|
const ShiftInt = std.math.Log2Int(MaskInt);
|
|
const kind = options.kind;
|
|
const direction = options.direction;
|
|
return struct {
|
|
const Self = @This();
|
|
|
|
// all bits which have not yet been iterated over
|
|
bits_remain: MaskInt,
|
|
// all words which have not yet been iterated over
|
|
words_remain: []const MaskInt,
|
|
// the offset of the current word
|
|
bit_offset: usize,
|
|
// the mask of the last word
|
|
last_word_mask: MaskInt,
|
|
|
|
fn init(masks: []const MaskInt, last_word_mask: MaskInt) Self {
|
|
if (masks.len == 0) {
|
|
return Self{
|
|
.bits_remain = 0,
|
|
.words_remain = &[_]MaskInt{},
|
|
.last_word_mask = last_word_mask,
|
|
.bit_offset = 0,
|
|
};
|
|
} else {
|
|
var result = Self{
|
|
.bits_remain = 0,
|
|
.words_remain = masks,
|
|
.last_word_mask = last_word_mask,
|
|
.bit_offset = if (direction == .forward) 0 else (masks.len - 1) * @bitSizeOf(MaskInt),
|
|
};
|
|
result.nextWord(true);
|
|
return result;
|
|
}
|
|
}
|
|
|
|
/// Returns the index of the next unvisited set bit
|
|
/// in the bit set, in ascending order.
|
|
pub fn next(self: *Self) ?usize {
|
|
while (self.bits_remain == 0) {
|
|
if (self.words_remain.len == 0) return null;
|
|
self.nextWord(false);
|
|
switch (direction) {
|
|
.forward => self.bit_offset += @bitSizeOf(MaskInt),
|
|
.reverse => self.bit_offset -= @bitSizeOf(MaskInt),
|
|
}
|
|
}
|
|
|
|
switch (direction) {
|
|
.forward => {
|
|
const next_index = @ctz(MaskInt, self.bits_remain) + self.bit_offset;
|
|
self.bits_remain &= self.bits_remain - 1;
|
|
return next_index;
|
|
},
|
|
.reverse => {
|
|
const leading_zeroes = @clz(MaskInt, self.bits_remain);
|
|
const top_bit = (@bitSizeOf(MaskInt) - 1) - leading_zeroes;
|
|
const no_top_bit_mask = (@as(MaskInt, 1) << @intCast(ShiftInt, top_bit)) - 1;
|
|
self.bits_remain &= no_top_bit_mask;
|
|
return top_bit + self.bit_offset;
|
|
},
|
|
}
|
|
}
|
|
|
|
// Load the next word. Don't call this if there
|
|
// isn't a next word. If the next word is the
|
|
// last word, mask off the padding bits so we
|
|
// don't visit them.
|
|
inline fn nextWord(self: *Self, comptime is_first_word: bool) void {
|
|
var word = switch (direction) {
|
|
.forward => self.words_remain[0],
|
|
.reverse => self.words_remain[self.words_remain.len - 1],
|
|
};
|
|
switch (kind) {
|
|
.set => {},
|
|
.unset => {
|
|
word = ~word;
|
|
if ((direction == .reverse and is_first_word) or
|
|
(direction == .forward and self.words_remain.len == 1))
|
|
{
|
|
word &= self.last_word_mask;
|
|
}
|
|
},
|
|
}
|
|
switch (direction) {
|
|
.forward => self.words_remain = self.words_remain[1..],
|
|
.reverse => self.words_remain.len -= 1,
|
|
}
|
|
self.bits_remain = word;
|
|
}
|
|
};
|
|
}
|
|
|
|
/// A range of indices within a bitset.
|
|
pub const Range = struct {
|
|
/// The index of the first bit of interest.
|
|
start: usize,
|
|
/// The index immediately after the last bit of interest.
|
|
end: usize,
|
|
};
|
|
|
|
// ---------------- Tests -----------------
|
|
|
|
const testing = std.testing;
|
|
|
|
fn testBitSet(a: anytype, b: anytype, len: usize) !void {
|
|
try testing.expectEqual(len, a.capacity());
|
|
try testing.expectEqual(len, b.capacity());
|
|
|
|
{
|
|
var i: usize = 0;
|
|
while (i < len) : (i += 1) {
|
|
a.setValue(i, i & 1 == 0);
|
|
b.setValue(i, i & 2 == 0);
|
|
}
|
|
}
|
|
|
|
try testing.expectEqual((len + 1) / 2, a.count());
|
|
try testing.expectEqual((len + 3) / 4 + (len + 2) / 4, b.count());
|
|
|
|
{
|
|
var iter = a.iterator(.{});
|
|
var i: usize = 0;
|
|
while (i < len) : (i += 2) {
|
|
try testing.expectEqual(@as(?usize, i), iter.next());
|
|
}
|
|
try testing.expectEqual(@as(?usize, null), iter.next());
|
|
try testing.expectEqual(@as(?usize, null), iter.next());
|
|
try testing.expectEqual(@as(?usize, null), iter.next());
|
|
}
|
|
a.toggleAll();
|
|
{
|
|
var iter = a.iterator(.{});
|
|
var i: usize = 1;
|
|
while (i < len) : (i += 2) {
|
|
try testing.expectEqual(@as(?usize, i), iter.next());
|
|
}
|
|
try testing.expectEqual(@as(?usize, null), iter.next());
|
|
try testing.expectEqual(@as(?usize, null), iter.next());
|
|
try testing.expectEqual(@as(?usize, null), iter.next());
|
|
}
|
|
|
|
{
|
|
var iter = b.iterator(.{ .kind = .unset });
|
|
var i: usize = 2;
|
|
while (i < len) : (i += 4) {
|
|
try testing.expectEqual(@as(?usize, i), iter.next());
|
|
if (i + 1 < len) {
|
|
try testing.expectEqual(@as(?usize, i + 1), iter.next());
|
|
}
|
|
}
|
|
try testing.expectEqual(@as(?usize, null), iter.next());
|
|
try testing.expectEqual(@as(?usize, null), iter.next());
|
|
try testing.expectEqual(@as(?usize, null), iter.next());
|
|
}
|
|
|
|
{
|
|
var i: usize = 0;
|
|
while (i < len) : (i += 1) {
|
|
try testing.expectEqual(i & 1 != 0, a.isSet(i));
|
|
try testing.expectEqual(i & 2 == 0, b.isSet(i));
|
|
}
|
|
}
|
|
|
|
a.setUnion(b.*);
|
|
{
|
|
var i: usize = 0;
|
|
while (i < len) : (i += 1) {
|
|
try testing.expectEqual(i & 1 != 0 or i & 2 == 0, a.isSet(i));
|
|
try testing.expectEqual(i & 2 == 0, b.isSet(i));
|
|
}
|
|
|
|
i = len;
|
|
var set = a.iterator(.{ .direction = .reverse });
|
|
var unset = a.iterator(.{ .kind = .unset, .direction = .reverse });
|
|
while (i > 0) {
|
|
i -= 1;
|
|
if (i & 1 != 0 or i & 2 == 0) {
|
|
try testing.expectEqual(@as(?usize, i), set.next());
|
|
} else {
|
|
try testing.expectEqual(@as(?usize, i), unset.next());
|
|
}
|
|
}
|
|
try testing.expectEqual(@as(?usize, null), set.next());
|
|
try testing.expectEqual(@as(?usize, null), set.next());
|
|
try testing.expectEqual(@as(?usize, null), set.next());
|
|
try testing.expectEqual(@as(?usize, null), unset.next());
|
|
try testing.expectEqual(@as(?usize, null), unset.next());
|
|
try testing.expectEqual(@as(?usize, null), unset.next());
|
|
}
|
|
|
|
a.toggleSet(b.*);
|
|
{
|
|
try testing.expectEqual(len / 4, a.count());
|
|
|
|
var i: usize = 0;
|
|
while (i < len) : (i += 1) {
|
|
try testing.expectEqual(i & 1 != 0 and i & 2 != 0, a.isSet(i));
|
|
try testing.expectEqual(i & 2 == 0, b.isSet(i));
|
|
if (i & 1 == 0) {
|
|
a.set(i);
|
|
} else {
|
|
a.unset(i);
|
|
}
|
|
}
|
|
}
|
|
|
|
a.setIntersection(b.*);
|
|
{
|
|
try testing.expectEqual((len + 3) / 4, a.count());
|
|
|
|
var i: usize = 0;
|
|
while (i < len) : (i += 1) {
|
|
try testing.expectEqual(i & 1 == 0 and i & 2 == 0, a.isSet(i));
|
|
try testing.expectEqual(i & 2 == 0, b.isSet(i));
|
|
}
|
|
}
|
|
|
|
a.toggleSet(a.*);
|
|
{
|
|
var iter = a.iterator(.{});
|
|
try testing.expectEqual(@as(?usize, null), iter.next());
|
|
try testing.expectEqual(@as(?usize, null), iter.next());
|
|
try testing.expectEqual(@as(?usize, null), iter.next());
|
|
try testing.expectEqual(@as(usize, 0), a.count());
|
|
}
|
|
{
|
|
var iter = a.iterator(.{ .direction = .reverse });
|
|
try testing.expectEqual(@as(?usize, null), iter.next());
|
|
try testing.expectEqual(@as(?usize, null), iter.next());
|
|
try testing.expectEqual(@as(?usize, null), iter.next());
|
|
try testing.expectEqual(@as(usize, 0), a.count());
|
|
}
|
|
|
|
const test_bits = [_]usize{
|
|
0, 1, 2, 3, 4, 5, 6, 7, 9, 10, 11, 22, 31, 32, 63, 64,
|
|
66, 95, 127, 160, 192, 1000,
|
|
};
|
|
for (test_bits) |i| {
|
|
if (i < a.capacity()) {
|
|
a.set(i);
|
|
}
|
|
}
|
|
|
|
for (test_bits) |i| {
|
|
if (i < a.capacity()) {
|
|
try testing.expectEqual(@as(?usize, i), a.findFirstSet());
|
|
try testing.expectEqual(@as(?usize, i), a.toggleFirstSet());
|
|
}
|
|
}
|
|
try testing.expectEqual(@as(?usize, null), a.findFirstSet());
|
|
try testing.expectEqual(@as(?usize, null), a.toggleFirstSet());
|
|
try testing.expectEqual(@as(?usize, null), a.findFirstSet());
|
|
try testing.expectEqual(@as(?usize, null), a.toggleFirstSet());
|
|
try testing.expectEqual(@as(usize, 0), a.count());
|
|
|
|
a.setRangeValue(.{ .start = 0, .end = len }, false);
|
|
try testing.expectEqual(@as(usize, 0), a.count());
|
|
|
|
a.setRangeValue(.{ .start = 0, .end = len }, true);
|
|
try testing.expectEqual(len, a.count());
|
|
|
|
a.setRangeValue(.{ .start = 0, .end = len }, false);
|
|
a.setRangeValue(.{ .start = 0, .end = 0 }, true);
|
|
try testing.expectEqual(@as(usize, 0), a.count());
|
|
|
|
a.setRangeValue(.{ .start = len, .end = len }, true);
|
|
try testing.expectEqual(@as(usize, 0), a.count());
|
|
|
|
if (len >= 1) {
|
|
a.setRangeValue(.{ .start = 0, .end = len }, false);
|
|
a.setRangeValue(.{ .start = 0, .end = 1 }, true);
|
|
try testing.expectEqual(@as(usize, 1), a.count());
|
|
try testing.expect(a.isSet(0));
|
|
|
|
a.setRangeValue(.{ .start = 0, .end = len }, false);
|
|
a.setRangeValue(.{ .start = 0, .end = len - 1 }, true);
|
|
try testing.expectEqual(len - 1, a.count());
|
|
try testing.expect(!a.isSet(len - 1));
|
|
|
|
a.setRangeValue(.{ .start = 0, .end = len }, false);
|
|
a.setRangeValue(.{ .start = 1, .end = len }, true);
|
|
try testing.expectEqual(@as(usize, len - 1), a.count());
|
|
try testing.expect(!a.isSet(0));
|
|
|
|
a.setRangeValue(.{ .start = 0, .end = len }, false);
|
|
a.setRangeValue(.{ .start = len - 1, .end = len }, true);
|
|
try testing.expectEqual(@as(usize, 1), a.count());
|
|
try testing.expect(a.isSet(len - 1));
|
|
|
|
if (len >= 4) {
|
|
a.setRangeValue(.{ .start = 0, .end = len }, false);
|
|
a.setRangeValue(.{ .start = 1, .end = len - 2 }, true);
|
|
try testing.expectEqual(@as(usize, len - 3), a.count());
|
|
try testing.expect(!a.isSet(0));
|
|
try testing.expect(a.isSet(1));
|
|
try testing.expect(a.isSet(len - 3));
|
|
try testing.expect(!a.isSet(len - 2));
|
|
try testing.expect(!a.isSet(len - 1));
|
|
}
|
|
}
|
|
}
|
|
|
|
fn testStaticBitSet(comptime Set: type) !void {
|
|
var a = Set.initEmpty();
|
|
var b = Set.initFull();
|
|
try testing.expectEqual(@as(usize, 0), a.count());
|
|
try testing.expectEqual(@as(usize, Set.bit_length), b.count());
|
|
|
|
try testBitSet(&a, &b, Set.bit_length);
|
|
}
|
|
|
|
test "IntegerBitSet" {
|
|
try testStaticBitSet(IntegerBitSet(0));
|
|
try testStaticBitSet(IntegerBitSet(1));
|
|
try testStaticBitSet(IntegerBitSet(2));
|
|
try testStaticBitSet(IntegerBitSet(5));
|
|
try testStaticBitSet(IntegerBitSet(8));
|
|
try testStaticBitSet(IntegerBitSet(32));
|
|
try testStaticBitSet(IntegerBitSet(64));
|
|
try testStaticBitSet(IntegerBitSet(127));
|
|
}
|
|
|
|
test "ArrayBitSet" {
|
|
if (@import("builtin").cpu.arch == .aarch64) {
|
|
// https://github.com/ziglang/zig/issues/9879
|
|
return error.SkipZigTest;
|
|
}
|
|
inline for (.{ 0, 1, 2, 31, 32, 33, 63, 64, 65, 254, 500, 3000 }) |size| {
|
|
try testStaticBitSet(ArrayBitSet(u8, size));
|
|
try testStaticBitSet(ArrayBitSet(u16, size));
|
|
try testStaticBitSet(ArrayBitSet(u32, size));
|
|
try testStaticBitSet(ArrayBitSet(u64, size));
|
|
try testStaticBitSet(ArrayBitSet(u128, size));
|
|
}
|
|
}
|
|
|
|
test "DynamicBitSetUnmanaged" {
|
|
const allocator = std.testing.allocator;
|
|
var a = try DynamicBitSetUnmanaged.initEmpty(allocator, 300);
|
|
try testing.expectEqual(@as(usize, 0), a.count());
|
|
a.deinit(allocator);
|
|
|
|
a = try DynamicBitSetUnmanaged.initEmpty(allocator, 0);
|
|
defer a.deinit(allocator);
|
|
for ([_]usize{ 1, 2, 31, 32, 33, 0, 65, 64, 63, 500, 254, 3000 }) |size| {
|
|
const old_len = a.capacity();
|
|
|
|
var tmp = try a.clone(allocator);
|
|
defer tmp.deinit(allocator);
|
|
try testing.expectEqual(old_len, tmp.capacity());
|
|
var i: usize = 0;
|
|
while (i < old_len) : (i += 1) {
|
|
try testing.expectEqual(a.isSet(i), tmp.isSet(i));
|
|
}
|
|
|
|
a.toggleSet(a); // zero a
|
|
tmp.toggleSet(tmp);
|
|
|
|
try a.resize(allocator, size, true);
|
|
try tmp.resize(allocator, size, false);
|
|
|
|
if (size > old_len) {
|
|
try testing.expectEqual(size - old_len, a.count());
|
|
} else {
|
|
try testing.expectEqual(@as(usize, 0), a.count());
|
|
}
|
|
try testing.expectEqual(@as(usize, 0), tmp.count());
|
|
|
|
var b = try DynamicBitSetUnmanaged.initFull(allocator, size);
|
|
defer b.deinit(allocator);
|
|
try testing.expectEqual(@as(usize, size), b.count());
|
|
|
|
try testBitSet(&a, &b, size);
|
|
}
|
|
}
|
|
|
|
test "DynamicBitSet" {
|
|
const allocator = std.testing.allocator;
|
|
var a = try DynamicBitSet.initEmpty(allocator, 300);
|
|
try testing.expectEqual(@as(usize, 0), a.count());
|
|
a.deinit();
|
|
|
|
a = try DynamicBitSet.initEmpty(allocator, 0);
|
|
defer a.deinit();
|
|
for ([_]usize{ 1, 2, 31, 32, 33, 0, 65, 64, 63, 500, 254, 3000 }) |size| {
|
|
const old_len = a.capacity();
|
|
|
|
var tmp = try a.clone(allocator);
|
|
defer tmp.deinit();
|
|
try testing.expectEqual(old_len, tmp.capacity());
|
|
var i: usize = 0;
|
|
while (i < old_len) : (i += 1) {
|
|
try testing.expectEqual(a.isSet(i), tmp.isSet(i));
|
|
}
|
|
|
|
a.toggleSet(a); // zero a
|
|
tmp.toggleSet(tmp); // zero tmp
|
|
|
|
try a.resize(size, true);
|
|
try tmp.resize(size, false);
|
|
|
|
if (size > old_len) {
|
|
try testing.expectEqual(size - old_len, a.count());
|
|
} else {
|
|
try testing.expectEqual(@as(usize, 0), a.count());
|
|
}
|
|
try testing.expectEqual(@as(usize, 0), tmp.count());
|
|
|
|
var b = try DynamicBitSet.initFull(allocator, size);
|
|
defer b.deinit();
|
|
try testing.expectEqual(@as(usize, size), b.count());
|
|
|
|
try testBitSet(&a, &b, size);
|
|
}
|
|
}
|
|
|
|
test "StaticBitSet" {
|
|
try testing.expectEqual(IntegerBitSet(0), StaticBitSet(0));
|
|
try testing.expectEqual(IntegerBitSet(5), StaticBitSet(5));
|
|
try testing.expectEqual(IntegerBitSet(@bitSizeOf(usize)), StaticBitSet(@bitSizeOf(usize)));
|
|
try testing.expectEqual(ArrayBitSet(usize, @bitSizeOf(usize) + 1), StaticBitSet(@bitSizeOf(usize) + 1));
|
|
try testing.expectEqual(ArrayBitSet(usize, 500), StaticBitSet(500));
|
|
}
|