Module 0x2::token
The Token module which implements a Closed Loop Token with a configurable policy. The policy is defined by a set of rules that must be satisfied for an action to be performed on the token.
The module is designed to be used with a TreasuryCap
to allow for minting
and burning of the Token
s. And can act as a replacement / extension or a
companion to existing open-loop (Coin
) systems.
Module: iota::balance iota::coin iota::token
Main type: `Balance<T>` `Coin<T>` `Token<T>`
Capability: `Supply<T>` <----> `TreasuryCap<T>` <----> `TreasuryCap<T>`
Abilities: store key + store key
The Token system allows for fine-grained control over the actions performed on the token. And hence it is highly suitable for applications that require control over the currency which a simple open-loop system can't provide.
- Resource
Token
- Resource
TokenPolicyCap
- Resource
TokenPolicy
- Struct
ActionRequest
- Struct
RuleKey
- Struct
TokenPolicyCreated
- Constants
- Function
new_policy
- Function
share_policy
- Function
transfer
- Function
spend
- Function
to_coin
- Function
from_coin
- Function
join
- Function
split
- Function
zero
- Function
destroy_zero
- Function
keep
- Function
new_request
- Function
confirm_request
- Function
confirm_request_mut
- Function
confirm_with_policy_cap
- Function
confirm_with_treasury_cap
- Function
add_approval
- Function
add_rule_config
- Function
rule_config
- Function
rule_config_mut
- Function
remove_rule_config
- Function
has_rule_config
- Function
has_rule_config_with_type
- Function
allow
- Function
disallow
- Function
add_rule_for_action
- Function
remove_rule_for_action
- Function
mint
- Function
burn
- Function
flush
- Function
is_allowed
- Function
rules
- Function
spent_balance
- Function
value
- Function
transfer_action
- Function
spend_action
- Function
to_coin_action
- Function
from_coin_action
- Function
action
- Function
amount
- Function
sender
- Function
recipient
- Function
approvals
- Function
spent
- Function
key
use 0x1::option;
use 0x1::string;
use 0x1::type_name;
use 0x2::balance;
use 0x2::coin;
use 0x2::dynamic_field;
use 0x2::event;
use 0x2::object;
use 0x2::transfer;
use 0x2::tx_context;
use 0x2::vec_map;
use 0x2::vec_set;
Resource Token
A single Token
with Balance
inside. Can only be owned by an address,
and actions performed on it must be confirmed in a matching TokenPolicy
.
struct Token<T> has key
Fields
id: object::UID
balance: balance::Balance<T>
The Balance of the
Token
.
Resource TokenPolicyCap
A Capability that manages a single TokenPolicy
specified in the for
field. Created together with TokenPolicy
in the new
function.
struct TokenPolicyCap<T> has store, key
Fields
id: object::UID
for: object::ID
Resource TokenPolicy
TokenPolicy
represents a set of rules that define what actions can be
performed on a Token
and which Rules
must be satisfied for the
action to succeed.
- For the sake of availability,
TokenPolicy
is akey
-only object. - Each
TokenPolicy
is managed by a matchingTokenPolicyCap
. - For an action to become available, there needs to be a record in the
rules
VecMap. To allow an action to be performed freely, there's anallow
function that can be called by theTokenPolicyCap
owner.
struct TokenPolicy<T> has key
Fields
id: object::UID
spent_balance: balance::Balance<T>
The balance that is effectively spent by the user on the "spend" action. However, actual decrease of the supply can only be done by the
TreasuryCap
owner whenflush
is called.This balance is effectively spent and cannot be accessed by anyone but the
TreasuryCap
owner.rules: vec_map::VecMap<string::String, vec_set::VecSet<type_name::TypeName>>
The set of rules that define what actions can be performed on the token. For each "action" there's a set of Rules that must be satisfied for the
ActionRequest
to be confirmed.
Struct ActionRequest
A request to perform an "Action" on a token. Stores the information
about the action to be performed and must be consumed by the confirm_request
or confirm_request_mut
functions when the Rules are satisfied.
struct ActionRequest<T>
Fields
name: string::String
Name of the Action to look up in the Policy. Name can be one of the default actions:
transfer
,spend
,to_coin
,from_coin
or a custom action.amount: u64
Amount is present in all of the txs
sender: address
Sender is a permanent field always
recipient: option::Option<address>
Recipient is only available in
transfer
action.spent_balance: option::Option<balance::Balance<T>>
The balance to be "spent" in the
TokenPolicy
, only available in thespend
action.approvals: vec_set::VecSet<type_name::TypeName>
Collected approvals (stamps) from completed
Rules
. They're matched againstTokenPolicy.rules
to determine if the request can be confirmed.
Struct RuleKey
Dynamic field key for the TokenPolicy
to store the Config
for a
specific action Rule
. There can be only one configuration per
Rule
per TokenPolicy
.
struct RuleKey<T> has copy, drop, store
Fields
is_protected: bool
Struct TokenPolicyCreated
An event emitted when a TokenPolicy
is created and shared. Because
TokenPolicy
can only be shared (and potentially frozen in the future),
we emit this event in the share_policy
function and mark it as mutable.
struct TokenPolicyCreated<T> has copy, drop
Fields
id: object::ID
ID of the
TokenPolicy
that was created.is_mutable: bool
Whether the
TokenPolicy
is "shared" (mutable) or "frozen" (immutable) - TBD.
Constants
Trying to perform an admin action with a wrong cap.
const ENotAuthorized: u64 = 2;
The balance is too low to perform the action.
const EBalanceTooLow: u64 = 3;
The balance is not zero when trying to confirm with TransferPolicyCap
.
const ECantConsumeBalance: u64 = 5;
Rule is trying to access a missing config (with type).
The rule was not approved.
const ENotApproved: u64 = 1;
The balance is not zero.
The action is not allowed (defined) in the policy.
const EUnknownAction: u64 = 0;
Using confirm_request_mut
without spent_balance
. Immutable version
of the function must be used instead.
const EUseImmutableConfirm: u64 = 7;
A Tag for the from_coin
action.
const FROM_COIN: vector<u8> = [102, 114, 111, 109, 95, 99, 111, 105, 110];
A Tag for the spend
action.
A Tag for the to_coin
action.
const TO_COIN: vector<u8> = [116, 111, 95, 99, 111, 105, 110];
A Tag for the transfer
action.
const TRANSFER: vector<u8> = [116, 114, 97, 110, 115, 102, 101, 114];
Function new_policy
Create a new TokenPolicy
and a matching TokenPolicyCap
.
The TokenPolicy
must then be shared using the share_policy
method.
TreasuryCap
guarantees full ownership over the currency, and is unique,
hence it is safe to use it for authorization.
public fun new_policy<T>(_treasury_cap: &coin::TreasuryCap<T>, ctx: &mut tx_context::TxContext): (token::TokenPolicy<T>, token::TokenPolicyCap<T>)
Implementation
public fun new_policy<T>(
_treasury_cap: &TreasuryCap<T>, ctx: &mut TxContext
): (TokenPolicy<T>, TokenPolicyCap<T>) {
let policy = TokenPolicy {
id: object::new(ctx),
spent_balance: balance::zero(),
rules: vec_map::empty()
};
let cap = TokenPolicyCap {
id: object::new(ctx),
for
: object::id(&policy)
};
(policy, cap)
}
Function share_policy
Share the TokenPolicy
. Due to key
-only restriction, it must be
shared after initialization.
public fun share_policy<T>(policy: token::TokenPolicy<T>)
Implementation
public fun share_policy<T>(policy: TokenPolicy<T>) {
event::emit(TokenPolicyCreated<T> {
id: object::id(&policy),
is_mutable: true,
});
transfer::share_object(policy)
}
Function transfer
Transfer a Token
to a recipient
. Creates an ActionRequest
for the
"transfer" action. The ActionRequest
contains the recipient
field
to be used in verification.
public fun transfer<T>(t: token::Token<T>, recipient: address, ctx: &mut tx_context::TxContext): token::ActionRequest<T>
Implementation
public fun transfer<T>(
t: Token<T>, recipient: address, ctx: &mut TxContext
): ActionRequest<T> {
let amount = t.balance.value();
transfer::transfer(t, recipient);
new_request(
transfer_action(),
amount,
option::some(recipient),
option::none(),
ctx
)
}
Function spend
Spend a Token
by unwrapping it and storing the Balance
in the
ActionRequest
for the "spend" action. The ActionRequest
contains
the spent_balance
field to be used in verification.
Spend action requires confirm_request_mut
to be called to confirm the
request and join the spent balance with the TokenPolicy.spent_balance
.
public fun spend<T>(t: token::Token<T>, ctx: &mut tx_context::TxContext): token::ActionRequest<T>
Implementation
public fun spend<T>(t: Token<T>, ctx: &mut TxContext): ActionRequest<T> {
let Token { id, balance } = t;
id.delete();
new_request(
spend_action(),
balance.value(),
option::none(),
option::some(balance),
ctx
)
}
Function to_coin
Convert Token
into an open Coin
. Creates an ActionRequest
for the
"to_coin" action.
public fun to_coin<T>(t: token::Token<T>, ctx: &mut tx_context::TxContext): (coin::Coin<T>, token::ActionRequest<T>)
Implementation
public fun to_coin<T>(
t: Token<T>, ctx: &mut TxContext
): (Coin<T>, ActionRequest<T>) {
let Token { id, balance } = t;
let amount = balance.value();
id.delete();
(
balance.into_coin(ctx),
new_request(
to_coin_action(),
amount,
option::none(),
option::none(),
ctx
)
)
}
Function from_coin
Convert an open Coin
into a Token
. Creates an ActionRequest
for
the "from_coin" action.
public fun from_coin<T>(coin: coin::Coin<T>, ctx: &mut tx_context::TxContext): (token::Token<T>, token::ActionRequest<T>)
Implementation
public fun from_coin<T>(
coin: Coin<T>, ctx: &mut TxContext
): (Token<T>, ActionRequest<T>) {
let amount = coin.value();
let token = Token {
id: object::new(ctx),
balance: coin.into_balance()
};
(
token,
new_request(
from_coin_action(),
amount,
option::none(),
option::none(),
ctx
)
)
}
Function join
Join two Token
s into one, always available.
public fun join<T>(token: &mut token::Token<T>, another: token::Token<T>)
Implementation
Function split
Split a Token
with amount
.
Aborts if the Token.balance
is lower than amount
.
public fun split<T>(token: &mut token::Token<T>, amount: u64, ctx: &mut tx_context::TxContext): token::Token<T>
Implementation
Function zero
Create a zero Token
.
public fun zero<T>(ctx: &mut tx_context::TxContext): token::Token<T>
Implementation
public fun zero<T>(ctx: &mut TxContext): Token<T> {
Token {
id: object::new(ctx),
balance: balance::zero(),
}
}
Function destroy_zero
Destroy an empty Token
, fails if the balance is non-zero.
Aborts if the Token.balance
is not zero.
public fun destroy_zero<T>(token: token::Token<T>)
Implementation
Function keep
Transfer the Token
to the transaction sender.
public fun keep<T>(token: token::Token<T>, ctx: &mut tx_context::TxContext)
Implementation
Function new_request
Create a new ActionRequest
.
Publicly available method to allow for custom actions.
public fun new_request<T>(name: string::String, amount: u64, recipient: option::Option<address>, spent_balance: option::Option<balance::Balance<T>>, ctx: &tx_context::TxContext): token::ActionRequest<T>
Implementation
public fun new_request<T>(
name: String,
amount: u64,
recipient: Option<address>,
spent_balance: Option<Balance<T>>,
ctx: &TxContext
): ActionRequest<T> {
ActionRequest {
name,
amount,
recipient,
spent_balance,
sender: ctx.sender(),
approvals: vec_set::empty(),
}
}
Function confirm_request
Confirm the request against the TokenPolicy
and return the parameters
of the request: (Name, Amount, Sender, Recipient).
Cannot be used for spend
and similar actions that deliver spent_balance
to the TokenPolicy
. For those actions use confirm_request_mut
.
Aborts if:
- the action is not allowed (missing record in
rules
) - action contains
spent_balance
(useconfirm_request_mut
) - the
ActionRequest
does not meet theTokenPolicy
rules for the action
public fun confirm_request<T>(policy: &token::TokenPolicy<T>, request: token::ActionRequest<T>, _ctx: &mut tx_context::TxContext): (string::String, u64, address, option::Option<address>)
Implementation
public fun confirm_request<T>(
policy: &TokenPolicy<T>,
request: ActionRequest<T>,
_ctx: &mut TxContext
): (String, u64, address, Option<address>) {
assert!(request.spent_balance.is_none(), ECantConsumeBalance);
assert!(policy.rules.contains(&request.name), EUnknownAction);
let ActionRequest {
name, approvals,
spent_balance,
amount, sender, recipient,
} = request;
spent_balance.destroy_none();
let rules = &(*policy.rules.get(&name)).into_keys();
let rules_len = rules.length();
let mut i = 0;
while (i < rules_len) {
let rule = &rules[i];
assert!(approvals.contains(rule), ENotApproved);
i = i + 1;
};
(name, amount, sender, recipient)
}
Function confirm_request_mut
Confirm the request against the TokenPolicy
and return the parameters
of the request: (Name, Amount, Sender, Recipient).
Unlike confirm_request
this function requires mutable access to the
TokenPolicy
and must be used on spend
action. After dealing with the
spent balance it calls confirm_request
internally.
See confirm_request
for the list of abort conditions.
public fun confirm_request_mut<T>(policy: &mut token::TokenPolicy<T>, request: token::ActionRequest<T>, ctx: &mut tx_context::TxContext): (string::String, u64, address, option::Option<address>)
Implementation
public fun confirm_request_mut<T>(
policy: &mut TokenPolicy<T>,
mut request: ActionRequest<T>,
ctx: &mut TxContext
): (String, u64, address, Option<address>) {
assert!(policy.rules.contains(&request.name), EUnknownAction);
assert!(request.spent_balance.is_some(), EUseImmutableConfirm);
policy.spent_balance.join(request.spent_balance.extract());
confirm_request(policy, request, ctx)
}
Function confirm_with_policy_cap
Confirm an ActionRequest
as the TokenPolicyCap
owner. This function
allows TokenPolicy
owner to perform Capability-gated actions ignoring
the ruleset specified in the TokenPolicy
.
Aborts if request contains spent_balance
due to inability of the
TokenPolicyCap
to decrease supply. For scenarios like this a
TreasuryCap
is required (see confirm_with_treasury_cap
).
public fun confirm_with_policy_cap<T>(_policy_cap: &token::TokenPolicyCap<T>, request: token::ActionRequest<T>, _ctx: &mut tx_context::TxContext): (string::String, u64, address, option::Option<address>)
Implementation
public fun confirm_with_policy_cap<T>(
_policy_cap: &TokenPolicyCap<T>,
request: ActionRequest<T>,
_ctx: &mut TxContext
): (String, u64, address, Option<address>) {
assert!(request.spent_balance.is_none(), ECantConsumeBalance);
let ActionRequest {
name, amount, sender, recipient, approvals: _, spent_balance
} = request;
spent_balance.destroy_none();
(name, amount, sender, recipient)
}
Function confirm_with_treasury_cap
Confirm an ActionRequest
as the TreasuryCap
owner. This function
allows TreasuryCap
owner to perform Capability-gated actions ignoring
the ruleset specified in the TokenPolicy
.
Unlike confirm_with_policy_cap
this function allows spent_balance
to be consumed, decreasing the total_supply
of the Token
.
public fun confirm_with_treasury_cap<T>(treasury_cap: &mut coin::TreasuryCap<T>, request: token::ActionRequest<T>, _ctx: &mut tx_context::TxContext): (string::String, u64, address, option::Option<address>)
Implementation
public fun confirm_with_treasury_cap<T>(
treasury_cap: &mut TreasuryCap<T>,
request: ActionRequest<T>,
_ctx: &mut TxContext
): (String, u64, address, Option<address>) {
let ActionRequest {
name, amount, sender, recipient, approvals: _,
spent_balance
} = request;
if (spent_balance.is_some()) {
treasury_cap.supply_mut().decrease_supply(spent_balance.destroy_some());
} else {
spent_balance.destroy_none();
};
(name, amount, sender, recipient)
}
Function add_approval
Add an "approval" to the ActionRequest
by providing a Witness.
Intended to be used by Rules to add their own approvals, however, can
be used to add arbitrary approvals to the request (not only the ones
required by the TokenPolicy
).
public fun add_approval<T, W: drop>(_t: W, request: &mut token::ActionRequest<T>, _ctx: &mut tx_context::TxContext)
Implementation
public fun add_approval<T, W: drop>(
_t: W, request: &mut ActionRequest<T>, _ctx: &mut TxContext
) {
request.approvals.insert(type_name::get<W>())
}
Function add_rule_config
Add a Config
for a Rule
in the TokenPolicy
. Rule configuration is
independent from the TokenPolicy.rules
and needs to be managed by the
Rule itself. Configuration is stored per Rule
and not per Rule
per
Action
to allow reuse in different actions.
- Rule witness guarantees that the
Config
is approved by the Rule. TokenPolicyCap
guarantees that theConfig
setup is initiated by theTokenPolicy
owner.
public fun add_rule_config<T, Rule: drop, Config: store>(_rule: Rule, self: &mut token::TokenPolicy<T>, cap: &token::TokenPolicyCap<T>, config: Config, _ctx: &mut tx_context::TxContext)
Implementation
public fun add_rule_config<T, Rule: drop, Config: store>(
_rule: Rule,
self: &mut TokenPolicy<T>,
cap: &TokenPolicyCap<T>,
config: Config,
_ctx: &mut TxContext
) {
assert!(object::id(self) == cap.for
, ENotAuthorized);
df::add(&mut self.id, key<Rule>(), config)
}
Function rule_config
Get a Config
for a Rule
in the TokenPolicy
. Requires Rule
witness, hence can only be read by the Rule
itself. This requirement
guarantees safety of the stored Config
and allows for simpler dynamic
field management inside the Rule Config (custom type keys are not needed
for access gating).
Aborts if the Config is not present.
public fun rule_config<T, Rule: drop, Config: store>(_rule: Rule, self: &token::TokenPolicy<T>): &Config
Implementation
public fun rule_config<T, Rule: drop, Config: store>(
_rule: Rule, self: &TokenPolicy<T>
): &Config {
assert!(has_rule_config_with_type<T, Rule, Config>(self), ENoConfig);
df::borrow(&self.id, key<Rule>())
}
Function rule_config_mut
Get mutable access to the Config
for a Rule
in the TokenPolicy
.
Requires Rule
witness, hence can only be read by the Rule
itself,
as well as TokenPolicyCap
to guarantee that the TokenPolicy
owner
is the one who initiated the Config
modification.
Aborts if:
- the Config is not present
TokenPolicyCap
is not matching theTokenPolicy
public fun rule_config_mut<T, Rule: drop, Config: store>(_rule: Rule, self: &mut token::TokenPolicy<T>, cap: &token::TokenPolicyCap<T>): &mut Config
Implementation
public fun rule_config_mut<T, Rule: drop, Config: store>(
_rule: Rule, self: &mut TokenPolicy<T>, cap: &TokenPolicyCap<T>
): &mut Config {
assert!(has_rule_config_with_type<T, Rule, Config>(self), ENoConfig);
assert!(object::id(self) == cap.for
, ENotAuthorized);
df::borrow_mut(&mut self.id, key<Rule>())
}
Function remove_rule_config
Remove a Config
for a Rule
in the TokenPolicy
.
Unlike the add_rule_config
, this function does not require a Rule
witness, hence can be performed by the TokenPolicy
owner on their own.
Rules need to make sure that the Config
is present when performing
verification of the ActionRequest
.
Aborts if:
- the Config is not present
TokenPolicyCap
is not matching theTokenPolicy
public fun remove_rule_config<T, Rule, Config: store>(self: &mut token::TokenPolicy<T>, cap: &token::TokenPolicyCap<T>, _ctx: &mut tx_context::TxContext): Config
Implementation
public fun remove_rule_config<T, Rule, Config: store>(
self: &mut TokenPolicy<T>,
cap: &TokenPolicyCap<T>,
_ctx: &mut TxContext
): Config {
assert!(has_rule_config_with_type<T, Rule, Config>(self), ENoConfig);
assert!(object::id(self) == cap.for
, ENotAuthorized);
df::remove(&mut self.id, key<Rule>())
}
Function has_rule_config
Check if a config for a Rule
is set in the TokenPolicy
without
checking the type of the Config
.
public fun has_rule_config<T, Rule>(self: &token::TokenPolicy<T>): bool
Implementation
public fun has_rule_config<T, Rule>(self: &TokenPolicy<T>): bool {
df::exists_<RuleKey<Rule>>(&self.id, key<Rule>())
}
Function has_rule_config_with_type
Check if a Config
for a Rule
is set in the TokenPolicy
and that
it matches the type provided.
public fun has_rule_config_with_type<T, Rule, Config: store>(self: &token::TokenPolicy<T>): bool
Implementation
public fun has_rule_config_with_type<T, Rule, Config: store>(
self: &TokenPolicy<T>
): bool {
df::exists_with_type<RuleKey<Rule>, Config>(&self.id, key<Rule>())
}
Function allow
Allows an action
to be performed on the Token
freely by adding an
empty set of Rules
for the action
.
Aborts if the TokenPolicyCap
is not matching the TokenPolicy
.
public fun allow<T>(self: &mut token::TokenPolicy<T>, cap: &token::TokenPolicyCap<T>, action: string::String, _ctx: &mut tx_context::TxContext)
Implementation
public fun allow<T>(
self: &mut TokenPolicy<T>,
cap: &TokenPolicyCap<T>,
action: String,
_ctx: &mut TxContext
) {
assert!(object::id(self) == cap.for
, ENotAuthorized);
self.rules.insert(action, vec_set::empty());
}
Function disallow
Completely disallows an action
on the Token
by removing the record
from the TokenPolicy.rules
.
Aborts if the TokenPolicyCap
is not matching the TokenPolicy
.
public fun disallow<T>(self: &mut token::TokenPolicy<T>, cap: &token::TokenPolicyCap<T>, action: string::String, _ctx: &mut tx_context::TxContext)
Implementation
public fun disallow<T>(
self: &mut TokenPolicy<T>,
cap: &TokenPolicyCap<T>,
action: String,
_ctx: &mut TxContext
) {
assert!(object::id(self) == cap.for
, ENotAuthorized);
self.rules.remove(&action);
}
Function add_rule_for_action
Adds a Rule for an action with name
in the TokenPolicy
.
Aborts if the TokenPolicyCap
is not matching the TokenPolicy
.
public fun add_rule_for_action<T, Rule: drop>(self: &mut token::TokenPolicy<T>, cap: &token::TokenPolicyCap<T>, action: string::String, ctx: &mut tx_context::TxContext)
Implementation
public fun add_rule_for_action<T, Rule: drop>(
self: &mut TokenPolicy<T>,
cap: &TokenPolicyCap<T>,
action: String,
ctx: &mut TxContext
) {
assert!(object::id(self) == cap.for
, ENotAuthorized);
if (!self.rules.contains(&action)) {
allow(self, cap, action, ctx);
};
self.rules.get_mut(&action).insert(type_name::get<Rule>())
}
Function remove_rule_for_action
Removes a rule for an action with name
in the TokenPolicy
. Returns
the config object to be handled by the sender (or a Rule itself).
Aborts if the TokenPolicyCap
is not matching the TokenPolicy
.
public fun remove_rule_for_action<T, Rule: drop>(self: &mut token::TokenPolicy<T>, cap: &token::TokenPolicyCap<T>, action: string::String, _ctx: &mut tx_context::TxContext)
Implementation
public fun remove_rule_for_action<T, Rule: drop>(
self: &mut TokenPolicy<T>,
cap: &TokenPolicyCap<T>,
action: String,
_ctx: &mut TxContext
) {
assert!(object::id(self) == cap.for
, ENotAuthorized);
self.rules.get_mut(&action).remove(&type_name::get<Rule>())
}
Function mint
Mint a Token
with a given amount
using the TreasuryCap
.
public fun mint<T>(cap: &mut coin::TreasuryCap<T>, amount: u64, ctx: &mut tx_context::TxContext): token::Token<T>
Implementation
Function burn
Burn a Token
using the TreasuryCap
.
public fun burn<T>(cap: &mut coin::TreasuryCap<T>, token: token::Token<T>)
Implementation
Function flush
Flush the TokenPolicy.spent_balance
into the TreasuryCap
. This
action is only available to the TreasuryCap
owner.
public fun flush<T>(self: &mut token::TokenPolicy<T>, cap: &mut coin::TreasuryCap<T>, _ctx: &mut tx_context::TxContext): u64
Implementation
Function is_allowed
Check whether an action is present in the rules VecMap.
public fun is_allowed<T>(self: &token::TokenPolicy<T>, action: &string::String): bool
Implementation
public fun is_allowed<T>(self: &TokenPolicy<T>, action: &String): bool {
self.rules.contains(action)
}
Function rules
Returns the rules required for a specific action.
public fun rules<T>(self: &token::TokenPolicy<T>, action: &string::String): vec_set::VecSet<type_name::TypeName>
Implementation
public fun rules<T>(
self: &TokenPolicy<T>, action: &String
): VecSet<TypeName> {
*self.rules.get(action)
}
Function spent_balance
Returns the spent_balance
of the TokenPolicy
.
public fun spent_balance<T>(self: &token::TokenPolicy<T>): u64
Implementation
public fun spent_balance<T>(self: &TokenPolicy<T>): u64 {
self.spent_balance.value()
}
Function value
Returns the balance
of the Token
.
public fun value<T>(t: &token::Token<T>): u64