For a more practical approach to utilizing XCM, refer to the XCM Docs. Please keep in mind that XCM is under active development.
This page can also be viewed at the
repository, where each instruction and register is explained in-depth.
- Programme Counter
- Error Handler
- Surplus Weight
- Refunded Weight
- Transact Status
- Transact Status Register
- Topic Register
XCVM Instruction Set
Instructions Application Example
The following presents the practical mapping of instructions to some core functionality in XCM.
- Functional Multichain Decomposition
ExpectAsset(MultiAssets)- Checks if the Holding register has a specific amount of assets, throws an error if it doesn't.
ExpectError(Option<(u32, Error)>)- Ensures the Error register contains the given error, and throws an error if it doesn't.
ExpectOrigin(MultiLocation)- Ensures the Origin register contains the expected origin, and throws an error if it doesn't.
QueryPallet- Queries the existence of a particular pallet type.
ExpectPallet- Ensure that a particular pallet with a particular version exists.
ReportTransactStatus(QueryResponseInfo)- Send a
QueryResponsemessage containing the value of the Transact Status Register to some destination.
ClearTransactStatus- Set the Transact Status Register to its default, cleared, value.
These instructions highlight the key instructions focused on Functional Multichain Decomposition.
LockAsset(MultiAsset, MultiLocation)- Lock the locally held asset and prevent further transfer or withdrawal.
UnlockAsset(MultiAsset, MultiLocation)- Remove the lock over
asseton this chain and (if nothing else is preventing it) allow the asset to be transferred.
NoteUnlockable(MultiAsset, MultiLocation)- Asset (
asset) has been locked on the
originsystem and may not be transferred. It may only be unlocked with the receipt of the
UnlockAssetinstruction from this chain.
RequestUnlock(MultiAsset, MultiLocation)- Send an
UnlockAssetinstruction to the
lockerfor the given