TokenAccountUpdateIterator
o1js / Modules / TokenAccountUpdateIterator
Class: TokenAccountUpdateIterator
Data structure to represent a forest of account updates that is being iterated over, in the context of a token manager contract.
The iteration is done in a depth-first manner.
let forest: AccountUpdateForest = ...;
let tokenIterator = TokenAccountUpdateIterator.create(forest, tokenId);
// process the first 5 account updates in the tree
for (let i = 0; i < 5; i++) {
let { accountUpdate, usesThisToken } = tokenIterator.next();
// ... do something with the account update ...
}
Important: Since this is specifically used by token manager contracts to process their entire subtree of account updates, the iterator skips subtrees that don't inherit token permissions and can therefore definitely not use the token.
So, the assumption is that the consumer of this iterator is only interested in account updates that use the token.
We still can't avoid processing some account updates that don't use the token, therefore the iterator returns a boolean
usesThisToken alongside each account update.
Table of contents
Constructors
Properties
Methods
Constructors
constructor
• new TokenAccountUpdateIterator(forest, mayUseToken, selfToken)
Parameters
| Name | Type |
|---|---|
forest | MerkleListIterator\<AccountUpdateTreeBase> |
mayUseToken | Object |
mayUseToken.inheritFromParent | Bool |
mayUseToken.parentsOwnToken | Bool |
selfToken | Field |
Defined in
lib/mina/token/forest-iterator.ts:59
Properties
currentLayer
• currentLayer: Layer
Defined in
lib/mina/token/forest-iterator.ts:55
selfToken
• selfToken: Field
Defined in
lib/mina/token/forest-iterator.ts:57
unfinishedParentLayers
• unfinishedParentLayers: MerkleList\<Layer>
Defined in
lib/mina/token/forest-iterator.ts:56
Methods
assertFinished
▸ assertFinished(message?): void
Parameters
| Name | Type |
|---|---|
message? | string |
Returns
void
Defined in
lib/mina/token/forest-iterator.ts:140
next
▸ next(): Object
Make a single step along a tree of account updates.
This function is guaranteed to visit each account update in the tree that uses the token exactly once, when called repeatedly.
The method makes a best effort to avoid visiting account updates that are not using the token,
and in particular, to avoid returning dummy updates.
However, neither can be ruled out. We're returning { update, usesThisToken: Bool } and let the
caller handle the irrelevant case where usesThisToken is false.
Returns
Object
| Name | Type |
|---|---|
accountUpdate | AccountUpdate |
usesThisToken | Bool |
Defined in
lib/mina/token/forest-iterator.ts:88
create
▸ Static create(forest, selfToken): TokenAccountUpdateIterator
Parameters
| Name | Type |
|---|---|
forest | AccountUpdateForest |
selfToken | Field |