Module 0x1::acl

Access control list (acl) module. An acl is a list of account addresses who have the access permission to a certain object. This module uses a vector to represent the list, but can be refactored to use a “set” instead when it’s available in the language in the future.

• Struct ACL
• Constants
• Function empty
• Function add
• Function remove
• Function contains
• Function assert_contains
• Specification
  • Struct ACL
  • Function add
  • Function remove
  • Function contains
  • Function assert_contains

use 0x1::error;
use 0x1::vector;

Struct ACL

struct ACL has copy, drop, store

Constants

The ACL already contains the address.

const ECONTAIN: u64 = 0;

The ACL does not contain the address.

const ENOT_CONTAIN: u64 = 1;

Function empty

Return an empty ACL.

public fun empty(): acl::ACL

public fun empty(): ACL {
    ACL{ list: vector::empty<address>() }
}

Function add

Add the address to the ACL.

public fun add(self: &mut acl::ACL, addr: address)

public fun add(self: &mut ACL, addr: address) {
    assert!(!self.list.contains(&addr), error::invalid_argument(ECONTAIN));
    self.list.push_back(addr);
}

Function remove

Remove the address from the ACL.

public fun remove(self: &mut acl::ACL, addr: address)

public fun remove(self: &mut ACL, addr: address) {
    let (found, index) = self.list.index_of(&addr);
    assert!(found, error::invalid_argument(ENOT_CONTAIN));
    self.list.remove(index);
}

Function contains

Return true iff the ACL contains the address.

public fun contains(self: &acl::ACL, addr: address): bool

public fun contains(self: &ACL, addr: address): bool {
    self.list.contains(&addr)
}

Function assert_contains

assert! that the ACL has the address.

public fun assert_contains(self: &acl::ACL, addr: address)

public fun assert_contains(self: &ACL, addr: address) {
    assert!(self.contains(addr), error::invalid_argument(ENOT_CONTAIN));
}

Specification

Struct ACL

struct ACL has copy, drop, store

list: vector<address>

invariant forall i in 0..len(list), j in 0..len(list): list[i] == list[j] ==> i == j;

fun spec_contains(self: ACL, addr: address): bool {
   exists a in self.list: a == addr
}

Function add

public fun add(self: &mut acl::ACL, addr: address)

aborts_if spec_contains(self, addr) with error::INVALID_ARGUMENT;
ensures spec_contains(self, addr);

Function remove

public fun remove(self: &mut acl::ACL, addr: address)

aborts_if !spec_contains(self, addr) with error::INVALID_ARGUMENT;
ensures !spec_contains(self, addr);

Function contains

public fun contains(self: &acl::ACL, addr: address): bool

ensures result == spec_contains(self, addr);

Function assert_contains

public fun assert_contains(self: &acl::ACL, addr: address)

aborts_if !spec_contains(self, addr) with error::INVALID_ARGUMENT;