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Sapling integration โ€‹

Sapling is a recent feature in Michelson. is compatible with Sapling in different ways: types, michelson implementation, compiler, and a fake implementation for test scenarios.

See reference Sapling and Sapling2 templates.

There are two types for Sapling: sp.TSaplingState(memo_size) for states and sp.TSaplingTransaction(memo_size) for transactions where memo_size is a constant integer between 0 and 65535 and corresponds to potentially included data in transaction. The memo_size parameter is optional in types sp.TSaplingState and sp.TSaplingTransaction as it may be computed through type inference.

SmartPy doesn't generate proper literals for Sapling types but an ad-hoc, fake, test implementation is provided for test scenarios.
This is not a proper Sapling transaction but it is enough to test contracts.

Methods โ€‹

Create sapling transaction for testing โ€‹

This is a fake / test version.

sp.sapling_test_transaction(source, target, amount, memo_size)
  • source is a Python string, empty string for minting tokens.

  • target is a Python string, empty string for burning tokens.

  • amount is a non-negative Python integer.

  • memo_size is a non-negative Python integer between 0 and 65535.

Create a sapling empty state โ€‹

Building an empty sp.TSaplingState with a default memo_size (Expected length for message of Sapling transaction)

  • memo_size is a uint16 value and represents the expected message length of the sapling transaction. (must be between 0 and 65535)

Verify a sapling update โ€‹

When state is a sp.TSaplingState(memo_size) and transaction a sp.TSaplingTransaction(memo_size), sp.sapling_verify_update(state, transaction) applies the transaction to the state, validates it and returns sp.none if it fails and sp.some(x) where x is of type sp.TTuple(sp.Bytes, sp.TInt, sp.TSaplingState(memo_size)).

sp.sapling_verify_update(state, transition)