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StdUtils

@opcat-labs/scrypt-ts-opcat v1.0.4

@opcat-labs/scrypt-ts-opcat / StdUtils

Class: StdUtils

Defined in: packages/scrypt-ts-opcat/src/smart-contract/builtin-libs/stdUtils.ts:28

A utility class providing standard helper methods for working with ByteStrings and numeric conversions. Includes methods for:

  • Checking ByteString length divisibility
  • Converting between numeric types (UInt32, UInt64) and ByteStrings
  • Little-endian unsigned integer conversions
  • Variable-length integer (VarInt) serialization/deserialization
  • Push data serialization for Bitcoin script All methods are static and annotated with @method() decorator.

Extends​

Constructors​

new StdUtils()​

new StdUtils(...args): StdUtils

Defined in: packages/scrypt-ts-opcat/src/smart-contract/smartContractLib.ts:32

Parameters​

args​

...SupportedParamType[]

Returns​

StdUtils

Inherited from​

SmartContractLib.constructor

Properties​

args​

args: any[] = []

Defined in: packages/scrypt-ts-opcat/src/smart-contract/smartContractLib.ts:31

Inherited from​

SmartContractLib.args

artifact​

static artifact: Artifact

Defined in: packages/scrypt-ts-opcat/src/smart-contract/smartContractLib.ts:16

Inherited from​

SmartContractLib.artifact

stateType?​

static optional stateType: string

Defined in: packages/scrypt-ts-opcat/src/smart-contract/smartContractLib.ts:17

Inherited from​

SmartContractLib.stateType

Methods​

byteStringToUInt32()​

static byteStringToUInt32(b): UInt32

Defined in: packages/scrypt-ts-opcat/src/smart-contract/builtin-libs/stdUtils.ts:75

Converts a 4-byte ByteString to an unsigned 32-bit integer in little-endian format.

Parameters​

b​

ByteString

The ByteString to convert (must be exactly 4 bytes long)

Returns​

UInt32

The converted UInt32 value

Throws​

Will throw an error if the input ByteString length is not 4 bytes

checkLenDivisibleBy()​

static checkLenDivisibleBy(b, n): bigint

Defined in: packages/scrypt-ts-opcat/src/smart-contract/builtin-libs/stdUtils.ts:37

Checks if the length of a ByteString is divisible by a given number and returns the quotient.

Parameters​

b​

ByteString

The ByteString to check

n​

bigint

The divisor to check against

Returns​

bigint

The quotient of the division (length / n)

Throws​

If the length is not divisible by n

fromLEUnsigned()​

static fromLEUnsigned(b): bigint

Defined in: packages/scrypt-ts-opcat/src/smart-contract/builtin-libs/stdUtils.ts:99

convert ByteString to unsigned integer, in sign-magnitude little endian

Parameters​

b​

ByteString

Returns​

bigint

returns a number

loadArtifact()​

static loadArtifact(artifact): typeof SmartContractLib

Defined in: packages/scrypt-ts-opcat/src/smart-contract/smartContractLib.ts:19

Parameters​

artifact​

Artifact

Returns​

typeof SmartContractLib

Inherited from​

SmartContractLib.loadArtifact

pushData()​

static pushData(buf): ByteString

Defined in: packages/scrypt-ts-opcat/src/smart-contract/builtin-libs/stdUtils.ts:149

Pushes data to a buffer with appropriate size header.

Parameters​

buf​

ByteString

The input data as a ByteString

Returns​

ByteString

The input data prefixed with appropriate size header in little-endian format

Remarks​

The header format follows standard Bitcoin script pushdata rules:

     - 0x4c for 1-byte length (0-255 bytes)
     - 0x4d for 2-byte length (256-65535 bytes)
     - 0x4e for 4-byte length (65536-4294967295 bytes)

Throws​

Will assert if input size exceeds 32-bit limit (4294967295 bytes)

readVarint()​

static readVarint(buf, pos): ReadVarintResult

Defined in: packages/scrypt-ts-opcat/src/smart-contract/builtin-libs/stdUtils.ts:184

read [VarInt (variable integer)][https://learnmeabitcoin.com/technical/general/compact-size/](https://learnmeabitcoin.com/technical/general/compact-size/)-encoded data from the beginning of 'buf'

Parameters​

buf​

ByteString

a buffer ByteString of format: [prefix FD/FE/FF +] length + data

pos​

bigint

Returns​

ReadVarintResult

return data

toLEUnsigned()​

static toLEUnsigned(n, l): ByteString

Defined in: packages/scrypt-ts-opcat/src/smart-contract/builtin-libs/stdUtils.ts:87

convert signed integer n to unsigned integer of l string, in little endian

Parameters​

n​

bigint

the number to be converted

l​

bigint

expected length

Returns​

ByteString

returns a ByteString

uint32ToByteString()​

static uint32ToByteString(n): ByteString

Defined in: packages/scrypt-ts-opcat/src/smart-contract/builtin-libs/stdUtils.ts:63

Converts a UInt32 number to a 4-byte little-endian ByteString.

Parameters​

n​

UInt32

The UInt32 number to convert

Returns​

ByteString

The resulting 4-byte little-endian ByteString

Throws​

If the input number is outside the UInt32 range (0 to 4294967295)

uint64ToByteString()​

static uint64ToByteString(n): ByteString

Defined in: packages/scrypt-ts-opcat/src/smart-contract/builtin-libs/stdUtils.ts:51

Converts a UInt64 value to a little-endian ByteString.

Parameters​

n​

UInt64

The UInt64 value to convert

Returns​

ByteString

The little-endian ByteString representation

Throws​

If the input value is outside UInt64 range (0 to 2^64-1)

writeVarInt()​

static writeVarInt(n): ByteString

Defined in: packages/scrypt-ts-opcat/src/smart-contract/builtin-libs/stdUtils.ts:114

Encodes a bigint into a variable-length integer (VarInt) format as ByteString. The encoding follows the standard VarInt scheme:

  • Values < 0xfd: encoded as 1 byte
  • Values < 0x10000: prefixed with 0xfd and encoded as 2 bytes (little-endian)
  • Values < 0x100000000: prefixed with 0xfe and encoded as 4 bytes (little-endian)
  • Larger values: prefixed with 0xff and encoded as 8 bytes (little-endian)

Parameters​

n​

bigint

The bigint value to encode

Returns​

ByteString

ByteString containing the VarInt encoded value