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Merge e5cc06e into b5c9ae1
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yj-qin authored May 29, 2024
2 parents b5c9ae1 + e5cc06e commit afb6f91
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Showing 3 changed files with 54 additions and 50 deletions.
92 changes: 48 additions & 44 deletions hashset/hashset.mbt
Original file line number Diff line number Diff line change
Expand Up @@ -21,7 +21,7 @@ pub fn HashSet::new[K]() -> HashSet[K] {
size: 0,
capacity: default_init_capacity,
growAt: calc_grow_threshold(default_init_capacity),
entries: Array::make(default_init_capacity, Empty),
entries: FixedArray::make(default_init_capacity, None),
}
}

Expand All @@ -39,27 +39,30 @@ pub fn insert[K : Hash + Eq](self : HashSet[K], key : K) -> Unit {
self.grow()
}
let hash = make_hash(key)
loop 0, self.index(hash), 0, hash, key {
i, idx, psl, hash, key => {
let entry = { psl: 0, hash, key }
loop 0, self.index(hash), entry {
i, idx, entry => {
if i == self.capacity {
abort("HashSet is full")
panic()
}
match self.entries[idx] {
Empty => {
self.entries[idx] = Valid(~psl, ~hash, ~key)
None => {
self.entries[idx] = Some(entry)
self.size += 1
break
}
Valid(psl=d, hash=h, key=k) => {
if h == hash && k == key {
self.entries[idx] = Valid(psl=d, hash=h, ~key)
Some(curr_entry) => {
if curr_entry.hash == entry.hash && curr_entry.key == entry.key {
self.entries[idx] = Some(entry)
break
}
if psl > d {
self.entries[idx] = Valid(~psl, ~hash, ~key)
continue i + 1, self.next_index(idx), d + 1, h, k
if entry.psl > curr_entry.psl {
self.entries[idx] = Some(entry)
curr_entry.psl += 1
continue i + 1, self.next_index(idx), curr_entry
}
continue i + 1, self.next_index(idx), psl + 1, hash, key
entry.psl += 1
continue i + 1, self.next_index(idx), entry
}
}
}
Expand All @@ -69,19 +72,19 @@ pub fn insert[K : Hash + Eq](self : HashSet[K], key : K) -> Unit {
/// Check if the hash set contains a key.
pub fn contains[K : Hash + Eq](self : HashSet[K], key : K) -> Bool {
let hash = make_hash(key)
for distance = 0, idx = self.index(hash)
distance < self.capacity
distance = distance + 1, idx = self.next_index(idx) {
for i = 0, idx = self.index(hash)
i < self.capacity
i = i + 1, idx = self.next_index(idx) {
match self.entries[idx] {
Valid(psl=d, hash=h, key=k) => {
if h == hash && k == key {
Some(entry) => {
if entry.hash == hash && entry.key == key {
return true
}
if distance > d {
if i > entry.psl {
return false
}
}
Empty => return false
None => return false
}
}
false
Expand All @@ -90,22 +93,22 @@ pub fn contains[K : Hash + Eq](self : HashSet[K], key : K) -> Bool {
/// Remove a key from hash set.
pub fn remove[K : Hash + Eq](self : HashSet[K], key : K) -> Unit {
let hash = make_hash(key)
for distance = 0, idx = self.index(hash)
distance < self.capacity
distance = distance + 1, idx = self.next_index(idx) {
for i = 0, idx = self.index(hash)
i < self.capacity
i = i + 1, idx = self.next_index(idx) {
match self.entries[idx] {
Valid(psl=d, hash=h, key=k) => {
if h == hash && k == key {
self.entries[idx] = Empty
Some(entry) => {
if entry.hash == hash && entry.key == key {
self.entries[idx] = None
self.shift_back(idx)
self.size -= 1
break
}
if distance > d {
if i > entry.psl {
return
}
}
Empty => ()
None => ()
}
}
}
Expand Down Expand Up @@ -135,19 +138,19 @@ pub fn iteri[K](self : HashSet[K], f : (Int, K) -> Unit) -> Unit {
let mut idx = 0
for i = 0; i < self.capacity; i = i + 1 {
match self.entries[i] {
Valid(~key, ..) => {
Some({ key, .. }) => {
f(idx, key)
idx += 1
}
_ => ()
None => ()
}
}
}

/// Clears the set, removing all keys. Keeps the allocated space.
pub fn clear[K](self : HashSet[K]) -> Unit {
for i = 0; i < self.capacity; i = i + 1 {
self.entries[i] = Empty
self.entries[i] = None
}
self.size = 0
}
Expand Down Expand Up @@ -200,8 +203,8 @@ pub fn as_iter[K](self : HashSet[K]) -> @iter.Iter[K] {
fn(yield) {
for i = 0, len = self.entries.length(); i < len; i = i + 1 {
match self.entries[i] {
Valid(~key, ..) => if yield(key).not() { break false }
_ => continue
Some({ key, .. }) => if yield(key).not() { break false }
None => continue
}
} else {
true
Expand All @@ -215,14 +218,15 @@ fn shift_back[K : Hash](self : HashSet[K], start_index : Int) -> Unit {
i < self.entries.length()
i = i + 1, prev = curr, curr = self.next_index(curr) {
match self.entries[curr] {
Valid(~psl, ~hash, ~key) => {
if psl == 0 {
Some(entry) => {
if entry.psl == 0 {
break
}
self.entries[prev] = Valid(psl=psl - 1, ~hash, ~key)
self.entries[curr] = Empty
entry.psl -= 1
self.entries[prev] = Some(entry)
self.entries[curr] = None
}
Empty => break
None => break
}
}
}
Expand All @@ -233,18 +237,18 @@ fn grow[K : Hash + Eq](self : HashSet[K]) -> Unit {
self.capacity = default_init_capacity
self.growAt = calc_grow_threshold(self.capacity)
self.size = 0
self.entries = Array::make(self.capacity, Empty)
self.entries = FixedArray::make(self.capacity, None)
return
}
let old_entries = self.entries
self.entries = Array::make(self.capacity * 2, Empty)
self.entries = FixedArray::make(self.capacity * 2, None)
self.capacity = self.capacity * 2
self.growAt = calc_grow_threshold(self.capacity)
self.size = 0
for i = 0; i < old_entries.length(); i = i + 1 {
match old_entries[i] {
Valid(~key, ..) => self.insert(key)
_ => ()
Some({ key, .. }) => self.insert(key)
None => ()
}
}
}
Expand Down Expand Up @@ -282,8 +286,8 @@ fn debug_entries[K : Show](self : HashSet[K]) -> String {
s += ","
}
match self.entries[i] {
Empty => s += "_"
Valid(~psl, ~key, ..) => s += "(\(psl),\(key))"
None => s += "_"
Some({ psl, key, .. }) => s += "(\(psl),\(key))"
}
}
s
Expand Down
2 changes: 1 addition & 1 deletion hashset/hashset_test.mbt
Original file line number Diff line number Diff line change
Expand Up @@ -140,7 +140,7 @@ test "clear" {
@assertion.assert_eq(m.size, 0)?
@assertion.assert_eq(m.capacity, 8)?
for i = 0; i < m.capacity; i = i + 1 {
@assertion.assert_is(m.entries[i], Empty)?
@assertion.assert_is(m.entries[i], None)?
}
}

Expand Down
10 changes: 5 additions & 5 deletions hashset/types.mbt
Original file line number Diff line number Diff line change
Expand Up @@ -12,10 +12,10 @@
// See the License for the specific language governing permissions and
// limitations under the License.

priv enum Entry[K] {
Empty
// (Probe Sequence Length, Hash, Key)
Valid(~psl : Int, ~hash : Int, ~key : K)
priv struct Entry[K] {
mut psl : Int
hash : Int
key : K
} derive(Debug)

/// A mutable hash set implements with Robin Hood hashing.
Expand All @@ -34,7 +34,7 @@ priv enum Entry[K] {
/// println(set.contains(3)) // output: true
/// ```
struct HashSet[K] {
mut entries : Array[Entry[K]]
mut entries : FixedArray[Option[Entry[K]]]
mut size : Int // active key count
mut capacity : Int // current capacity
mut growAt : Int // threshold that triggers grow
Expand Down

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