Module sui::bag

A bag is a heterogeneous map-like collection. The collection is similar to sui::table in that its keys and values are not stored within the Bag value, but instead are stored using Sui's object system. The Bag struct acts only as a handle into the object system to retrieve those keys and values.
Note that this means that Bag values with exactly the same key-value mapping will not be equal, with ==, at runtime. For example

let bag1 = bag::new();
let bag2 = bag::new();
bag::add(&mut bag1, 0, false);
bag::add(&mut bag1, 1, true);
bag::add(&mut bag2, 0, false);
bag::add(&mut bag2, 1, true);
// bag1 does not equal bag2, despite having the same entries
assert!(&bag1 != &bag2);

At it's core, sui::bag is a wrapper around UID that allows for access to sui::dynamic_field while preventing accidentally stranding field values. A UID can be deleted, even if it has dynamic fields associated with it, but a bag, on the other hand, must be empty to be destroyed.

use std::ascii;
use std::bcs;
use std::option;
use std::string;
use std::vector;
use sui::address;
use sui::dynamic_field;
use sui::hex;
use sui::object;
use sui::tx_context;

Struct Bag

public struct Bag has key, store

Click to open

Fields

id: sui::object::UID

the ID of this bag

size: u64

the number of key-value pairs in the bag

Constants

const EBagNotEmpty: u64 = 0;

Function new

Creates a new, empty bag

public fun new(ctx: &mut sui::tx_context::TxContext): sui::bag::Bag

Function add

Adds a key-value pair to the bag bag: &mut Bag.
Aborts with sui::dynamic_field::EFieldAlreadyExists if the bag already has an entry with that key k: K.

public fun add<K: copy, drop, store, V: store>(bag: &mut sui::bag::Bag, k: K, v: V)

Function borrow

Immutable borrows the value associated with the key in the bag bag: &Bag.
Aborts with sui::dynamic_field::EFieldDoesNotExist if the bag does not have an entry with that key k: K.
Aborts with sui::dynamic_field::EFieldTypeMismatch if the bag has an entry for the key, but the value does not have the specified type.

public fun borrow<K: copy, drop, store, V: store>(bag: &sui::bag::Bag, k: K): &V

Function borrow_mut

Mutably borrows the value associated with the key in the bag bag: &mut Bag.
Aborts with sui::dynamic_field::EFieldDoesNotExist if the bag does not have an entry with that key k: K.
Aborts with sui::dynamic_field::EFieldTypeMismatch if the bag has an entry for the key, but the value does not have the specified type.

public fun borrow_mut<K: copy, drop, store, V: store>(bag: &mut sui::bag::Bag, k: K): &mut V

Function remove

Mutably borrows the key-value pair in the bag bag: &mut Bag and returns the value.
Aborts with sui::dynamic_field::EFieldDoesNotExist if the bag does not have an entry with that key k: K.
Aborts with sui::dynamic_field::EFieldTypeMismatch if the bag has an entry for the key, but the value does not have the specified type.

public fun remove<K: copy, drop, store, V: store>(bag: &mut sui::bag::Bag, k: K): V

Function contains

Returns true iff there is an value associated with the key k: K in the bag bag: &Bag

public fun contains<K: copy, drop, store>(bag: &sui::bag::Bag, k: K): bool

Function contains_with_type

Returns true iff there is an value associated with the key k: K in the bag bag: &Bag with an assigned value of type V

public fun contains_with_type<K: copy, drop, store, V: store>(bag: &sui::bag::Bag, k: K): bool

Function length

Returns the size of the bag, the number of key-value pairs

public fun length(bag: &sui::bag::Bag): u64

Function is_empty

Returns true iff the bag is empty (if length returns 0)

public fun is_empty(bag: &sui::bag::Bag): bool

Function destroy_empty

Destroys an empty bag.
Aborts with EBagNotEmpty if the bag still contains values

public fun destroy_empty(bag: sui::bag::Bag)