Class: CairoTypeOption

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

A Cairo core::option::Option::<T> : either a value, or nothing.

On the wire it is an enum with two branches — 0 then the value for Some, 1 alone for None. Which branch is meant cannot be read off the value, since Some(0) and None would look alike, so building one from raw data asks for the variant.

This is the internal shape. What a caller writes and reads back is CairoOption, and handing one of those here says the variant by itself.

Example

const type = 'core::option::Option::<core::integer::u8>';
new CairoTypeOption(7, type, cairoTypeStrategy, CairoOptionVariant.Some).toApiRequest();
// ["0", "7"]
new CairoTypeOption(undefined, type, cairoTypeStrategy, CairoOptionVariant.None).toApiRequest();
// ["1"]

Constructors

Constructor

new CairoTypeOption(content, optionCairoType, parsingStrategy, variant?, subType?): CairoTypeOption

Defined in: src/utils/cairoDataTypes/cairoTypeOption.ts:120

Build an option, from a value a caller passed or from the felts of a response.

A CairoOption says its own branch, so variant is not given with one — nor with the response iterator, which reads the branch off the wire. Anywhere else it is required.

subType is what makes an option of options work. Handed a CairoOption, this constructor unwraps it and calls itself with what was inside, which for a nested option is another CairoOption; the flag stops that second call from unwrapping again and losing a level, and sends it to the strategy instead, where the inner type is what gets built.

Parameters

content

unknown

the value, a CairoOption, an instance already built, or the response iterator

optionCairoType

string

the abi type, core::option::Option::<T>

parsingStrategy

AllowArray<CairoTypeStrategy>

how to build the value

variant?

number

which branch, when the content does not say. Must be omitted when content is the response iterator.

subType?

boolean = false

true when called from the unwrapping of a nested CairoOption, which is the only caller that should set it

Returns

CairoTypeOption

Throws

when the type is not an option, when the variant is missing, absurd, or contradicts the content

Example

const type = 'core::option::Option::<core::integer::u8>';
new CairoTypeOption(7, type, cairoTypeStrategy, CairoOptionVariant.Some).toApiRequest();
// ["0", "7"]
new CairoTypeOption(new CairoOption(CairoOptionVariant.Some, 7), type, cairoTypeStrategy).toApiRequest();
// ["0", "7"]     the CairoOption says the branch
new CairoTypeOption(['0x0', '0x20'].values(), type, cairoTypeStrategy).toApiRequest();
// ["0", "32"]    read off a response

Properties

dynamicSelector

static dynamicSelector: "CairoTypeOption"

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

The name this class is registered under in a strategy's dynamicSelectors.

Example

const result = CairoTypeOption.dynamicSelector;
// result = "CairoTypeOption"

---

dynamicSelector

readonly dynamicSelector: "CairoTypeOption" = CairoTypeOption.dynamicSelector

Defined in: src/utils/cairoDataTypes/cairoTypeOption.ts:51

The selector on the instance, which is how a composite holding it knows what built it.

Example

const type = 'core::option::Option::<core::integer::u8>';
const result = new CairoTypeOption(7, type, cairoTypeStrategy, CairoOptionVariant.Some)
  .dynamicSelector;
// result = "CairoTypeOption"

---

content

readonly content: CairoType | undefined

Defined in: src/utils/cairoDataTypes/cairoTypeOption.ts:63

The value this option carries, or nothing at all when it is None.

Example

const type = 'core::option::Option::<core::integer::u8>';
const result = new CairoTypeOption(undefined, type, cairoTypeStrategy, CairoOptionVariant.None)
  .content;
// result = undefined

---

optionCairoType

readonly optionCairoType: string

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

The abi type this option was built for.

Example

const type = 'core::option::Option::<core::integer::u8>';
const result = new CairoTypeOption(7, type, cairoTypeStrategy, CairoOptionVariant.Some)
  .optionCairoType;
// result = "core::option::Option::<core::integer::u8>"

---

isVariantSome

readonly isVariantSome: boolean

Defined in: src/utils/cairoDataTypes/cairoTypeOption.ts:87

Which of the two branches this option is on.

Example

const type = 'core::option::Option::<core::integer::u8>';
const result = new CairoTypeOption(7, type, cairoTypeStrategy, CairoOptionVariant.Some)
  .isVariantSome;
// result = true

Methods

getVariantSomeType()

static getVariantSomeType(type): string

Defined in: src/utils/cairoDataTypes/cairoTypeOption.ts:265

The type a Some carries, read out of the option type.

Parameters

type

string

the abi type to read

Returns

string

the type between the angle brackets

Throws

when there is no type between brackets

Example

const result = CairoTypeOption.getVariantSomeType('core::option::Option::<core::integer::u8>');
// result = "core::integer::u8"

---

validate()

static validate(_input, type, variant): void

Defined in: src/utils/cairoDataTypes/cairoTypeOption.ts:290

Throw unless this is an option type and this variant is one of its two branches.

The value is not read here : what it is worth is the business of the type the option carries, and is checked when that value is built.

Parameters

_input

unknown

the value, which this does not read

type

string

the abi type it is meant for

variant

VariantType | undefined

the branch, when one was given

Returns

void

Throws

when the type is not an option, or the variant is neither 0 nor 1

Example

const type = 'core::option::Option::<core::integer::u16>';
CairoTypeOption.validate(200, type, CairoOptionVariant.Some); // passes
CairoTypeOption.validate(200, type, 3);
// throws Error("In Cairo option, only 0 or 1 variants are authorized.")

---

is()

static is(input, type, variant): boolean

Defined in: src/utils/cairoDataTypes/cairoTypeOption.ts:321

Can this be read as an option of this type, on this branch?

The non-throwing form of CairoTypeOption.validate.

Parameters

input

unknown

the value to test

type

string

the abi type it is meant for

variant

VariantType

the branch

Returns

boolean

true when the type and the variant both fit

Example

const type = 'core::option::Option::<core::integer::u16>';
const result = CairoTypeOption.is(200, type, CairoOptionVariant.Some);
// result = true
const result2 = CairoTypeOption.is(200, type, 3);
// result2 = false

---

isAbiType()

static isAbiType(type): boolean

Defined in: src/utils/cairoDataTypes/cairoTypeOption.ts:342

Is this abi type an option?

Parameters

type

string

the abi type to test

Returns

boolean

true for core::option::Option::<T>

Example

const result = CairoTypeOption.isAbiType('core::option::Option::<core::integer::u16>');
// result = true
const result2 = CairoTypeOption.isAbiType('core::integer::u16');
// result2 = false

---

toApiRequest()

toApiRequest(): string[]

Defined in: src/utils/cairoDataTypes/cairoTypeOption.ts:361

Serialize to the felts a contract call carries.

The branch comes first, and the value only follows it on Some — a None is one felt, and that is the whole of it.

Returns

string[]

the branch then the value, flagged as compiled

Example

const type = 'core::option::Option::<core::integer::u8>';
new CairoTypeOption(8, type, cairoTypeStrategy, CairoOptionVariant.Some).toApiRequest();
// ["0", "8"]
new CairoTypeOption(undefined, type, cairoTypeStrategy, CairoOptionVariant.None).toApiRequest();
// ["1"]

---

decompose()

decompose(strategyDecompose): CairoOption<any>

Defined in: src/utils/cairoDataTypes/cairoTypeOption.ts:413

Read the option back as the CairoOption a caller reads.

Parameters

strategyDecompose

AllowArray<CairoTypeStrategy>

how to read the value back

Returns

CairoOption<any>

the option, on the branch it was built with

Throws

when no strategy can read the value back

Example

const type = 'core::option::Option::<core::integer::u8>';
const option = new CairoTypeOption(3, type, cairoTypeStrategy, CairoOptionVariant.Some);
const result = option.decompose(cairoTypeStrategy).unwrap();
// result = 3n