Class: CairoUint64

Defined in: src/utils/cairoDataTypes/uint64.ts:30

A Cairo core::integer::u64 : a whole number in [0, 18446744073709551615], carried in one felt252.

The value is kept as a bigint, so the shape of the input does not survive — 7017280452245743464, '7017280452245743464' and '0x6162636465666768' give the same u64. A string that reads as text rather than as a number is taken for its UTF-8 bytes, which is why 'abcdefgh' is 7017280452245743464 and not a rejected input.

An already built instance is not an accepted input : handed back to the constructor it is seen as an object and refused. Inside the library it is unwrapCairoScalar that reduces an instance to its number before an abi slot receives it.

Example

// the same value, reached four ways
new CairoUint64(7017280452245743464).toBigInt(); //     7017280452245743464n
new CairoUint64('7017280452245743464').toBigInt(); //   7017280452245743464n
new CairoUint64('0x6162636465666768').toBigInt(); // 7017280452245743464n
new CairoUint64('abcdefgh').toBigInt(); //    7017280452245743464n     the UTF-8 bytes of the text

Constructors

Constructor

new CairoUint64(data): CairoUint64

Defined in: src/utils/cairoDataTypes/uint64.ts:65

Build from a number, a string or a boolean, refusing anything out of the u64 range.

A string is read as a number when it spells one — decimal or hexadecimal — and as UTF-8 text otherwise. Text therefore only fits here up to 8 ASCII characters : one more already makes a number past 18446744073709551615.

Parameters

data

unknown

the value to carry, within [0, 18446744073709551615]

Returns

CairoUint64

Throws

when the value is null, undefined, an object, a decimal number, '0x', or out of range

Example

const result = new CairoUint64('abcdefgh').toApiRequest();
// result = ["7017280452245743464"]

Properties

abiSelector

static abiSelector: string = 'core::integer::u64'

Defined in: src/utils/cairoDataTypes/uint64.ts:49

The abi type this class serializes.

Example

const result = CairoUint64.abiSelector;
// result = "core::integer::u64"

---

data

data: bigint

Defined in: src/utils/cairoDataTypes/uint64.ts:39

The value, always as a bigint.

Example

const result = new CairoUint64('0x6162636465666768').data;
// result = 7017280452245743464n

Methods

__processData()

static __processData(data): bigint

Defined in: src/utils/cairoDataTypes/uint64.ts:85

Turn an accepted input into its number, before the range is checked.

Nothing here refuses a value : validate is what reads this number and decides. So an input far outside the u64 range comes back untouched rather than raising.

Parameters

data

unknown

the value to convert

Returns

bigint

the number the input spells, of whatever size

Example

const result = CairoUint64.__processData('abcdefgh');
// result = 7017280452245743464n
const result2 = CairoUint64.__processData('abcdefghi');
// result2 = 1796423795774910326889n     (past the u64 range, and returned all the same)

---

validate()

static validate(data): void

Defined in: src/utils/cairoDataTypes/uint64.ts:165

Throw unless the value can be carried by a u64.

Five things are refused, each with its own message : a null or undefined value, an object or an array, a number with a decimal part, '0x', and a value outside [0, 18446744073709551615]. A text string reaches that last check as the number its bytes spell, so 'abcdefghi' is refused for being out of range.

Parameters

data

unknown

the value to check

Returns

void

Throws

when the value is null, undefined, an object, a decimal number, '0x', or out of range

Example

CairoUint64.validate(5000000000); // passes
CairoUint64.validate(18446744073709551616);
// throws Error("Value is out of u64 range [0, 18446744073709551615]")

---

is()

static is(data): boolean

Defined in: src/utils/cairoDataTypes/uint64.ts:196

Can this value be carried by a u64?

The non-throwing form of CairoUint64.validate, so it answers false for every input that one refuses, whatever the reason.

Parameters

data

unknown

the value to test

Returns

boolean

true when the value fits in a u64

Example

const result = CairoUint64.is('abcdefgh');
// result = true     (7017280452245743464, the UTF-8 bytes of the text)
const result2 = CairoUint64.is('abcdefghi');
// result2 = false   (1796423795774910326889, past the u64 range)

---

isAbiType()

static isAbiType(abiType): boolean

Defined in: src/utils/cairoDataTypes/uint64.ts:217

Is this abi type the one this class serializes?

Parameters

abiType

string

the abi type to test

Returns

boolean

true for core::integer::u64

Example

const result = CairoUint64.isAbiType('core::integer::u64');
// result = true
const result2 = CairoUint64.isAbiType('core::felt252');
// result2 = false

---

factoryFromApiResponse()

static factoryFromApiResponse(responseIterator): CairoUint64

Defined in: src/utils/cairoDataTypes/uint64.ts:235

Read one u64 off a contract response, advancing the iterator past it.

The felts a node returns are hex strings, and one is consumed per call, so successive calls read successive return values.

Parameters

responseIterator

Iterator<string>

the response felts, positioned on this u64

Returns

CairoUint64

the u64 that was read

Example

const response = ['0x12a05f200'];
const result = CairoUint64.factoryFromApiResponse(response.values()).toBigInt();
// result = 5000000000n

---

toApiRequest()

toApiRequest(): string[]

Defined in: src/utils/cairoDataTypes/uint64.ts:102

Serialize to the single felt a contract call carries.

Returns

string[]

one decimal-string felt, flagged as compiled

Example

const result = new CairoUint64(5000000000).toApiRequest();
// result = ["5000000000"]

---

toBigInt()

toBigInt(): bigint

Defined in: src/utils/cairoDataTypes/uint64.ts:115

The value as a number.

Returns

bigint

the number this u64 holds

Example

const result = new CairoUint64(18446744073709551615).toBigInt();
// result = 18446744073709551615n

---

decodeUtf8()

decodeUtf8(): string

Defined in: src/utils/cairoDataTypes/uint64.ts:131

Read the value back as the UTF-8 text its bytes spell.

Only a value that was text to begin with comes back as readable text. Any other number is decoded all the same, and what it gives is whatever its bytes happen to mean.

Returns

string

the bytes decoded as UTF-8

Example

const result = new CairoUint64('abcdefgh').decodeUtf8();
// result = "abcdefgh"

---

toHexString()

toHexString(): string

Defined in: src/utils/cairoDataTypes/uint64.ts:146

The value in hexadecimal, without padding.

Returns

string

the number as a 0x-prefixed hex string

Example

const result = new CairoUint64(5000000000).toHexString();
// result = "0x12a05f200"
const result2 = new CairoUint64(0).toHexString();
// result2 = "0x0"     (one digit, not "0x00")