Functions

The following functions and operators are available when compiling Ivy to Bitcoin Script:

• checkSig(publicKey: PublicKey, sig: Signature) -> Boolean: check that the signature sig is a valid signature on the spending transaction by the private key corresponding to publicKey.

• checkMultiSig(publicKeys: [PublicKey], sigs: [Signature]) -> Boolean: check that each of the signatures in sigs is a valid signature on the spending transaction by the private key corresponding to one of the publicKeys. The signatures must be provided in the same order as their respective public keys.

• after(time: Time) -> Boolean: check that the current block time (or block height) is after time. This uses the transaction’s nLockTime field and the CHECKLOCKTIMEVERIFY instruction.

• older(duration: Duration) -> Boolean: check that the contract being spent has been on the blockchain for at least duration (w). This uses the input’s sequence number and the CHECKSEQUENCEVERIFY instruction.

• sha256(preimage: (T: HashableType)) -> Sha256(T): compute the SHA-256 hash of preimage

• sha1(preimage: (T: HashableType)) -> Sha1(T): compute the SHA-1 hash of preimage

• ripemd160(preimage: (T: HashableType)) -> Ripemd160(T): compute the RIPEMD-160 hash of preimage

• bytes(item: T) -> Bytes: coerce item to a bytestring (of type Bytes). This function does not have any effect on the compiled output or on script execution (since the Bitcoin Script VM treats every item as a bytestring); it only affects typechecking. (This cannot be called on an item of type Value.)

• ==, !=: check equality of any two values of the same type. (Note: because of certain limitations of Bitcoin Script, using these operators on Booleans is not allowed.)