Struct Asset 

pub struct Asset { /* private fields */ }

Assets are encoded as an AssetId and an AssetValue, each encodable as one word.

The AssetId uniquely identifies the asset and contains the AccountId of the issuer and the AssetClass, which can further divide a single account’s assets into different classes. It also contains the AssetComposition, which describes how assets compose, meaning whether they can be merged or split. For example, cominbing two fungible assets with the same ID and amounts 3 and 4 into a single one with amount 7 is called “merging”. Splitting would be the reverse operation.

It is impossible to find a collision between two fungible assets issued by different faucets as the faucet ID is part of the asset’s ID and the protocol’s AccountTree guarantees that account IDs are globally unique.

Assets are generally opaque to the protocol, with the [FungibleAsset] being the exception. It is built-in in the sense that the tx kernel knows how to merge and split such assets without requiring a procedure call to the issuing account, which improves performance.

Fungible assets

All assets carrying AssetComposition::Fungible are interpreted as a fungible asset, and this composition allows merging and splitting of assets.

• A fungible asset’s value layout is: [amount, 0, 0, 0].
• A fungible asset’s ID layout is: [0, 0, faucet_id_suffix_and_metadata, faucet_id_prefix].

Where:

• amount is the AssetAmount that the asset holds and cannot be greater than AssetAmount::MAX and thus fits into a felt.
• the remaining elements in the value word must be zero.
• faucet_id_prefix is the prefix of the faucet ID which issues the asset.
• faucet_id_suffix_and_metadata is the suffix of the faucet ID which issues the asset and the asset metadata, which is the encoding version together with the AssetComposition. See AssetId for more details on the ID’s layout.
• the asset class limbs must be zero, which means two instances of the same fungible asset have the same asset ID and will be merged together when stored in the same account’s vault.

Implementations

impl Asset

pub fn new(id: AssetId, value: Word) -> Result<Asset, AssetError>

Creates an asset from the provided ID and value.

The value of a fungible asset is validated, see FungibleAsset::from_id_and_value. The value of any other asset is opaque to the protocol and therefore not validated.

Errors

Returns an error if:

• The asset is fungible and FungibleAsset::from_id_and_value fails.

pub fn from_id_and_value_words( id: Word, value: Word, ) -> Result<Asset, AssetError>

Creates an asset from the provided ID and value.

Prefer Self::new for more type safety.

Errors

Returns an error if:

• The provided ID does not contain a valid faucet ID.
• Self::new fails.

pub fn is_same(&self, other: &Asset) -> bool

Returns true if this asset is the same as the specified asset.

Two assets are defined to be the same if their asset IDs match.

pub fn is_fungible(&self) -> bool

Returns true if this asset has AssetComposition::Fungible, false otherwise.

pub fn is_non_fungible(&self) -> bool

Returns true if this asset has AssetComposition::None, false otherwise.

pub fn faucet_id(&self) -> AccountId

Returns the ID of the faucet that issued this asset.

pub fn id(&self) -> AssetId

Returns the AssetId which uniquely identifies this asset in the account vault.

pub fn value(&self) -> AssetValue

Returns the AssetValue of this asset.

pub fn to_id_word(&self) -> Word

Returns the asset’s AssetId encoded to a Word.

pub fn to_value_word(&self) -> Word

Returns the asset’s value encoded to a Word.

pub fn as_elements(&self) -> [Felt; 8]

Returns the asset encoded as elements.

The first four elements contain the asset ID and the last four elements contain the asset value.

pub fn as_fungible(&self) -> Option<FungibleAsset>

Returns this asset as a FungibleAsset, or None if the asset is not a valid fungible asset.

pub fn unwrap_fungible(&self) -> FungibleAsset

Returns this asset as a FungibleAsset.

Panics

Panics if the asset is not fungible.

Trait Implementations

impl Clone for Asset

fn clone(&self) -> Asset

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Copy for Asset

impl Debug for Asset

fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>

Formats the value using the given formatter.

impl Deserializable for Asset

fn read_from<R>(source: &mut R) -> Result<Asset, DeserializationError>

where R: ByteReader,

Reads a sequence of bytes from the provided source, attempts to deserialize these bytes into Self, and returns the result.

fn min_serialized_size() -> usize

Returns the minimum serialized size for one instance of this type.

fn read_from_bytes(bytes: &[u8]) -> Result<Self, DeserializationError>

Attempts to deserialize the provided bytes into Self and returns the result.

fn read_from_bytes_with_budget( bytes: &[u8], budget: usize, ) -> Result<Self, DeserializationError>

Deserializes Self from bytes with a byte budget limit.

impl Display for Asset

fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>

Formats the value using the given formatter.

impl Eq for Asset

impl From<Asset> for AssetId

fn from(asset: Asset) -> AssetId

Converts to this type from the input type.

impl From<FungibleAsset> for Asset

fn from(asset: FungibleAsset) -> Asset

Converts to this type from the input type.

impl From<NonFungibleAsset> for Asset

fn from(asset: NonFungibleAsset) -> Asset

Converts to this type from the input type.

impl PartialEq for Asset

fn eq(&self, other: &Asset) -> bool

Equality operator ==.

fn ne(&self, other: &Rhs) -> bool

Inequality operator !=.

impl Serializable for Asset

fn write_into<W>(&self, target: &mut W)

where W: ByteWriter,

Serializes self into bytes and writes these bytes into the target.

fn get_size_hint(&self) -> usize

Returns an estimate of how many bytes are needed to represent self.

fn to_bytes(&self) -> Vec<u8>

Serializes self into a vector of bytes.

impl StructuralPartialEq for Asset