Functions¶

Math Functions¶

int abs(int a)

Returns an absolute value of the argument.
int min(int a, int b)

Returns the smaller argument.
int max(int a, int b)

Returns the larger argument.
bool within(int x, int min, int max)

Returns true if x >= min && x < max.

Ripemd160 ripemd160([byte] bytes)

Returns a RIPEMD-160 hash of the argument.
Sha1 sha1([byte] bytes)

Returns a SHA-1 hash of the argument.
Sha256 sha256([byte] bytes)

Returns a SHA-256 hash of the argument.
Ripemd160 hash160([byte] bytes)

Returns RIPEMD-160 hash of SHA-256 hash of the argument.
Sha256 hash256([byte] bytes)

Returns double SHA-256 hash of the argument.

bool checkSig(Sig sig, PubKey pk)

Validates a transaction signature sig againnst a public key pk.
bool checkMultiSig(List<Sig> sigs, List<PubKey> pks)

Validates the set of signatures against the set of public keys.
bool checkDataSig(DataSig sig, [byte] msg, PubKey pk)

Validates a signature sig of an arbitrary message msg against a public key pk.

Verification checkLockTime(Time t)

Validates whether the spending transaction occurs after time t, expressed as a block height or a timestamp.
Verification checkSequence(TimeSpan duration)

Validates whether the spending transaction happens after duration relative to the locking transaction, expressed as a number of blocks or number of 512 seconds-long periods.

[byte] num2bin(int num, int size)

Converts a number num into a bytes list. Bytes are reversed and padded with zeros up to size.
[byte] Bytes(int num)

Reinterprets a number num as a bytes list without affecting the byte order.
int bin2num([byte] data)

Converts a bytes list data to an integer. The list is treated as little-endian.
int size([byte] data)

Returns the length of data.
int checkSize([byte; x] data)

Returns true it the runtime size of the byte array matches the declared size x.
bin fst([bin, bin] data)

Returns the first element of a tuple (result of @ operator).
```
bin left = fst(0xaabbccdd @ 2);
// left == 0xaabb
```
bin snd([bin, bin] data)

Returns the second element of a tuple (result of @ operator).
```
bin right = snd(0xaabbccdd @ 2);
// right == 0xccdd
```
DataSig toDataSig(Sig data)

Converts a signature suitable for checkSig function (with a sighash flag) to a signature suitable for checkDataSig function (without a sighash flag).
```
verify checkSig(sig, pubKey);
verify checkDataSig(toDataSig(sig), preimageHash, pubKey);
```