linked_table.md

Module 0x2::linked_table

Similar to moveos_std::table but the values are linked together, allowing for ordered insertion and removal

• Resource TablePlaceholder
• Resource LinkedTable
• Struct Node
• Constants
• Function new
• Function front
• Function back
• Function push_front
• Function push_back
• Function borrow
• Function borrow_mut
• Function prev
• Function next
• Function remove
• Function pop_front
• Function pop_back
• Function contains
• Function length
• Function is_empty
• Function destroy_empty
• Function drop

use 0x1::option;
use 0x2::object;

Resource TablePlaceholder

struct TablePlaceholder has key

Resource LinkedTable

struct LinkedTable<K: copy, drop, store, V: store> has store, key

Struct Node

struct Node<K: copy, drop, store, V: store> has store

Constants

const ErrorTableIsEmpty: u64 = 1;

const ErrorTableNotEmpty: u64 = 0;

Function new

Creates a new, empty table

public fun new<K: copy, drop, store, V: store>(): linked_table::LinkedTable<K, V>

Function front

Returns the key for the first element in the table, or None if the table is empty

public fun front<K: copy, drop, store, V: store>(table: &linked_table::LinkedTable<K, V>): &option::Option<K>

Function back

Returns the key for the last element in the table, or None if the table is empty

public fun back<K: copy, drop, store, V: store>(table: &linked_table::LinkedTable<K, V>): &option::Option<K>

Function push_front

Inserts a key-value pair at the front of the table, i.e. the newly inserted pair will be the first element in the table Aborts with if the table already has an entry with that key k: K.

public fun push_front<K: copy, drop, store, V: store>(table: &mut linked_table::LinkedTable<K, V>, k: K, value: V)

Function push_back

Inserts a key-value pair at the back of the table, i.e. the newly inserted pair will be the last element in the table Aborts if the table already has an entry with that key k: K.

public fun push_back<K: copy, drop, store, V: store>(table: &mut linked_table::LinkedTable<K, V>, k: K, value: V)

Function borrow

Immutable borrows the value associated with the key in the table table: &LinkedTable<K, V>. Aborts if the table does not have an entry with that key k: K.

public fun borrow<K: copy, drop, store, V: store>(table: &linked_table::LinkedTable<K, V>, k: K): &V

Function borrow_mut

Mutably borrows the value associated with the key in the table table: &mut LinkedTable<K, V>. Aborts if the table does not have an entry with that key k: K.

public fun borrow_mut<K: copy, drop, store, V: store>(table: &mut linked_table::LinkedTable<K, V>, k: K): &mut V

Function prev

Borrows the key for the previous entry of the specified key k: K in the table table: &LinkedTable<K, V>. Returns None if the entry does not have a predecessor. Aborts if the table does not have an entry with that key k: K

public fun prev<K: copy, drop, store, V: store>(table: &linked_table::LinkedTable<K, V>, k: K): &option::Option<K>

Function next

Borrows the key for the next entry of the specified key k: K in the table table: &LinkedTable<K, V>. Returns None if the entry does not have a predecessor. Aborts if the table does not have an entry with that key k: K

public fun next<K: copy, drop, store, V: store>(table: &linked_table::LinkedTable<K, V>, k: K): &option::Option<K>

Function remove

Removes the key-value pair in the table table: &mut LinkedTable<K, V> and returns the value. This splices the element out of the ordering. Aborts if the table does not have an entry with that key k: K. Note: this is also what happens when the table is empty.

public fun remove<K: copy, drop, store, V: store>(table: &mut linked_table::LinkedTable<K, V>, k: K): V

Function pop_front

Removes the front of the table table: &mut LinkedTable<K, V> and returns the value. Aborts with ETableIsEmpty if the table is empty

public fun pop_front<K: copy, drop, store, V: store>(table: &mut linked_table::LinkedTable<K, V>): (K, V)

Function pop_back

Removes the back of the table table: &mut LinkedTable<K, V> and returns the value. Aborts with ETableIsEmpty if the table is empty

public fun pop_back<K: copy, drop, store, V: store>(table: &mut linked_table::LinkedTable<K, V>): (K, V)

Function contains

Returns true iff there is a value associated with the key k: K in table table: &LinkedTable<K, V>

public fun contains<K: copy, drop, store, V: store>(table: &linked_table::LinkedTable<K, V>, k: K): bool

Function length

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

public fun length<K: copy, drop, store, V: store>(table: &linked_table::LinkedTable<K, V>): u64

Function is_empty

Returns true if the table is empty (if length returns 0)

public fun is_empty<K: copy, drop, store, V: store>(table: &linked_table::LinkedTable<K, V>): bool

Function destroy_empty

Destroys an empty table Aborts with ETableNotEmpty if the table still contains values

public fun destroy_empty<K: copy, drop, store, V: store>(table: linked_table::LinkedTable<K, V>)

Function drop

Drop a possibly non-empty table. Usable only if the value type V has the drop ability

public fun drop<K: copy, drop, store, V: drop, store>(table_obj: object::Object<linked_table::LinkedTable<K, V>>)