Standard Library

Standard library is a set of built-in functions, structures and variables.

The version of the Standard library in the script is set by the STDLIB_VERSION directive.

We recommend to use version 5 of the Standard Library when developing applications. Key features of version 5 are described in the Standard Library Version 5 article.

The table below shows the version differences.

#	Version 3	Version 4	Version 5
Script	Added: • dApp script • Directives • Annotations • Custom functions • FOLD<N> macro		Added: • dApp-to-dApp invocation
Data types	Added: • List		Added: • Any • BigInt
Variables	Added built-in variables: • this • lastBlock • nil • Rounding methods: CEILING, DOWN, FLOOR etc. • Designations of hashing algorithms: NOALG, MD5, SHA1 etc.		Added strict variables
Structures	Added: Script actions: • DataEntry • ScriptTransfer Script results: • ScriptResult • TransferSet • WriteSet Common structures: • Asset • AttachedPayment • BlockInfo • Invocation Transaction structures: • InvokeScriptTransaction	Added: Script actions: • BinaryEntry • BooleanEntry • IntegerEntry • StringEntry • DeleteEntry • Issue • Reissue • Burn • SponsorFee Common structures: • BalanceDetails Transaction structures: • UpdateAssetInfoTransaction Modified: Common structures: • Asset • BlockInfo • Invocation Transaction structures: • DataTransaction • InvokeScriptTransaction • IssueTransaction Deleted: • DataEntry • ScriptResult • TransferSet • WriteSet	Added: Script actions: • Lease • LeaseCancel Modified: Common structures: • Invocation
Built-in functions	Added: Blockchain functions: • assetInfo • blockInfoByHeight • transferTransactionById Converting functions: • parseInt • parseIntValue • toInt • toUtf8String • toString(Address) Decoding functions: • fromBase16String Encoding fuctions: • toBase16String Math functions: • log • pow String functions: • indexOf • lastIndexOf • split Union functions: • value • valueOrErrorMessage Verification functions: • checkMerkleProof • rsaVerify Deleted: • transactionById	Added: Blockchain functions: • calculateAssetId Converting fuctions: • transferTransactionFromProto List functions: • containsElement • indexOf • lastIndexOf • min/max • removeByIndex Math functions: • median String functions: • contains • makeString Union functions: • valueOrElse Verification functions: • bn256groth16verify • createMerkleRoot • ecrecover • groth16verify Deleted: • checkMerkleProof • extract	Added: dApp-to-dApp invocation function: • invoke • reentrantInvoke Account data storage functions: • getBinary(key: String): ByteVector|Unit • getBinaryValue(key: String): ByteVector • getBoolean(key: String): Boolean|Unit • getBooleanValue(key: String): Boolean • getInteger(key: String): Int|Unit • getIntegerValue(key: String): Int • getString(key: String): String|Unit • getStringValue(key: String): String • isDataStorageUntouched Blockchain functions: • calculateLeaseId • scriptHash Converting functions: • parseBigInt • parseBigIntValue • toBigInt(ByteVector): BigInt • toBigInt(ByteVector, Int, Int): BigInt • toBigInt(Int): BigInt • toBytes(BigInt): ByteVector • toInt(BigInt): Int • toString(BigInt): String List functions: • max(List[BigInt]): Bigint • min(List[BigInt]): Bigint Math functions: • fraction(Int, Int, Int, Union): Int • fraction(BigInt, BigInt, BigInt): BigInt • fraction(BigInt, BigInt, BigInt, Union): BigInt • log(BigInt, Int, BigInt, Int, Int, Union): BigInt • median(List[BigInt]): Bigint • pow(BigInt, Int, BigInt, Int, Int, Union): BigInt
Operators		Added: • :+ • ++
Complexity changes	• - operator: 9 → 1 • ! operator: 11 → 1 • != operator: 26 → 1 • throw: 2 → 1 • isDefined: 35 → 1	• + operator: 10 → 2 for ByteVector values, 10 → 20 for strings • Functions: see complexity changes in the Built-in Functions article • Added blake2b256_<N>Kb, keccak256_<N>Kb, sha256_<N>Kb, rsaVerify_<N>Kb, sigVerify_<N>Kb range of similar   functions with different complexity depending   on the argument size limit	• fraction(Int, Int, Int): Int: 1 → 14
Data size		• String: up to 32,767 bytes • ByteVector: up to 32,767 (except the bodyBytes field   of the transaction structure)