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Module iota::vec_set

use std::option;
use std::vector;

Struct VecSet​

A set data structure backed by a vector. The set is guaranteed not to contain duplicate keys. All operations are O(N) in the size of the set. The intention of this data structure is only to provide the convenience of programming against a set API. Sets that need sorted iteration rather than insertion order iteration should be handwritten.

public struct VecSet<K: copy, drop> has copy, drop, store
Fields
contents: vector<K>

Constants​

This key already exists in the map

const EKeyAlreadyExists: u64 = 0;

This key does not exist in the map

const EKeyDoesNotExist: u64 = 1;

Function empty​

Create an empty VecSet

public fun empty<K: copy, drop>(): iota::vec_set::VecSet<K>
Implementation
public fun empty<K: copy + drop>(): VecSet<K> {
VecSet { contents: vector[] }
}

Function singleton​

Create a singleton VecSet that only contains one element.

public fun singleton<K: copy, drop>(key: K): iota::vec_set::VecSet<K>
Implementation
public fun singleton<K: copy + drop>(key: K): VecSet<K> {
VecSet { contents: vector[key] }
}

Function insert​

Insert a key into self. Aborts if key is already present in self.

public fun insert<K: copy, drop>(self: &mut iota::vec_set::VecSet<K>, key: K)
Implementation
public fun insert<K: copy + drop>(self: &mut VecSet<K>, key: K) {
assert!(!self.contains(&key), EKeyAlreadyExists);
self.contents.push_back(key)
}

Function remove​

Remove the entry key from self. Aborts if key is not present in self.

public fun remove<K: copy, drop>(self: &mut iota::vec_set::VecSet<K>, key: &K)
Implementation
public fun remove<K: copy + drop>(self: &mut VecSet<K>, key: &K) {
let idx = get_idx(self, key);
self.contents.remove(idx);
}

Function contains​

Return true if self contains an entry for key, false otherwise

public fun contains<K: copy, drop>(self: &iota::vec_set::VecSet<K>, key: &K): bool
Implementation
public fun contains<K: copy + drop>(self: &VecSet<K>, key: &K): bool {
get_idx_opt(self, key).is_some()
}

Function size​

Return the number of entries in self

public fun size<K: copy, drop>(self: &iota::vec_set::VecSet<K>): u64
Implementation
public fun size<K: copy + drop>(self: &VecSet<K>): u64 {
self.contents.length()
}

Function is_empty​

Return true if self has 0 elements, false otherwise

public fun is_empty<K: copy, drop>(self: &iota::vec_set::VecSet<K>): bool
Implementation
public fun is_empty<K: copy + drop>(self: &VecSet<K>): bool {
size(self) == 0
}

Function into_keys​

Unpack self into vectors of keys. The output keys are stored in insertion order, not sorted.

public fun into_keys<K: copy, drop>(self: iota::vec_set::VecSet<K>): vector<K>
Implementation
public fun into_keys<K: copy + drop>(self: VecSet<K>): vector<K> {
let VecSet { contents } = self;
contents
}

Function from_keys​

Construct a new VecSet from a vector of keys. The keys are stored in insertion order (the original keys ordering) and are not sorted.

public fun from_keys<K: copy, drop>(keys: vector<K>): iota::vec_set::VecSet<K>
Implementation
public fun from_keys<K: copy + drop>(mut keys: vector<K>): VecSet<K> {
keys.reverse();
let mut set = empty();
while (keys.length() != 0) set.insert(keys.pop_back());
set
}

Function keys​

Borrow the contents of the VecSet to access content by index without unpacking. The contents are stored in insertion order, not sorted.

public fun keys<K: copy, drop>(self: &iota::vec_set::VecSet<K>): &vector<K>
Implementation
public fun keys<K: copy + drop>(self: &VecSet<K>): &vector<K> {
&self.contents
}

Function get_idx_opt​

Find the index of key in self. Return None if key is not in self. Note that keys are stored in insertion order, not sorted.

fun get_idx_opt<K: copy, drop>(self: &iota::vec_set::VecSet<K>, key: &K): std::option::Option<u64>
Implementation
fun get_idx_opt<K: copy + drop>(self: &VecSet<K>, key: &K): Option<u64> {
let mut i = 0;
let n = size(self);
while (i < n) {
if (&self.contents[i] == key) {
return option::some(i)
};
i = i + 1;
};
option::none()
}

Function get_idx​

Find the index of key in self. Aborts if key is not in self. Note that map entries are stored in insertion order, not sorted.

fun get_idx<K: copy, drop>(self: &iota::vec_set::VecSet<K>, key: &K): u64
Implementation
fun get_idx<K: copy + drop>(self: &VecSet<K>, key: &K): u64 {
let idx_opt = get_idx_opt(self, key);
assert!(idx_opt.is_some(), EKeyDoesNotExist);
idx_opt.destroy_some()
}