Class: CairoBool

Defined in: src/utils/cairoDataTypes/bool.ts:26

A Cairo core::bool : true or false, carried in one felt252 as 1 or 0.

A boolean is the natural input, but the two numbers a bool occupies on the wire are accepted too — 1, 0n, '1', '0x0' — because that is how a bool comes back from a node, as a felt rather than as a JS value. Any other number is refused : a bool is not a felt narrowed to a range, it is exactly two values.

Example

// the same value, reached three ways
new CairoBool(true).toBoolean(); //   true
new CairoBool(1).toBoolean(); //      true
new CairoBool('0x1').toBoolean(); //  true

Constructors

Constructor

new CairoBool(data): CairoBool

Defined in: src/utils/cairoDataTypes/bool.ts:57

Build from a boolean, or from the numbers 0 and 1.

Parameters

data

unknown

the value to carry : a boolean, 0 or 1

Returns

CairoBool

Throws

when the value is text, a decimal number, not a felt252 input, or a number other than 0 or 1

Example

const result = new CairoBool(false).toApiRequest();
// result = ["0"]

Properties

abiSelector

static abiSelector: string = 'core::bool'

Defined in: src/utils/cairoDataTypes/bool.ts:45

The abi type this class serializes.

Example

const result = CairoBool.abiSelector;
// result = "core::bool"

---

data

data: boolean

Defined in: src/utils/cairoDataTypes/bool.ts:35

The value, always as a boolean.

Example

const result = new CairoBool('0x1').data;
// result = true

Methods

__processData()

static __processData(data): boolean

Defined in: src/utils/cairoDataTypes/bool.ts:75

Turn an accepted input into its boolean.

Nothing here refuses a value : validate is what decides, and only a boolean, a 0 or a 1 reaches this point.

Parameters

data

unknown

the value to convert

Returns

boolean

the boolean the input spells

Example

const result = CairoBool.__processData('0x1');
// result = true

---

validate()

static validate(data): void

Defined in: src/utils/cairoDataTypes/bool.ts:143

Throw unless the value can be carried by a bool.

Text is refused first, then a number with a decimal part. A number or a bigint is read as it is, so that a negative one reaches the last check. Anything else is read as a felt252 — which is what refuses a null, an object or an unsupported type. The value is finally checked to be one of the only two numbers a bool can hold.

Parameters

data

unknown

the value to check

Returns

void

Throws

when the value is text, a decimal number, not a felt252 input, or a number other than 0 or 1

Example

CairoBool.validate(true); // passes
CairoBool.validate(2);
// throws Error("Only values 0 or 1 are possible in a core::bool, received 2")
CairoBool.validate(-1);
// throws Error("Only values 0 or 1 are possible in a core::bool, received -1")

---

is()

static is(data): boolean

Defined in: src/utils/cairoDataTypes/bool.ts:175

Can this value be carried by a bool?

The non-throwing form of CairoBool.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 is a boolean, a 0 or a 1

Example

const result = CairoBool.is(1);
// result = true
const result2 = CairoBool.is(2);
// result2 = false     (a bool is exactly two values)

---

isAbiType()

static isAbiType(abiType): boolean

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

Is this abi type the one this class serializes?

Parameters

abiType

string

the abi type to test

Returns

boolean

true for core::bool

Example

const result = CairoBool.isAbiType('core::bool');
// result = true
const result2 = CairoBool.isAbiType('core::felt252');
// result2 = false

---

factoryFromApiResponse()

static factoryFromApiResponse(responseIterator): CairoBool

Defined in: src/utils/cairoDataTypes/bool.ts:214

Read one bool 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 bool

Returns

CairoBool

the bool that was read

Example

const response = ['0x1'];
const result = CairoBool.factoryFromApiResponse(response.values()).toBoolean();
// result = true

---

toApiRequest()

toApiRequest(): string[]

Defined in: src/utils/cairoDataTypes/bool.ts:93

Serialize to the single felt a contract call carries.

Returns

string[]

one decimal-string felt, "1" or "0", flagged as compiled

Example

const result = new CairoBool(true).toApiRequest();
// result = ["1"]
const result2 = new CairoBool(false).toApiRequest();
// result2 = ["0"]

---

toBoolean()

toBoolean(): boolean

Defined in: src/utils/cairoDataTypes/bool.ts:106

The value as a boolean.

Returns

boolean

the boolean this bool holds

Example

const result = new CairoBool(1).toBoolean();
// result = true

---

toHexString()

toHexString(): string

Defined in: src/utils/cairoDataTypes/bool.ts:121

The value in hexadecimal, as the felt a bool occupies.

Returns

string

"0x1" for true, "0x0" for false

Example

const result = new CairoBool(true).toHexString();
// result = "0x1"
const result2 = new CairoBool(false).toHexString();
// result2 = "0x0"