Class OptionBuilder<IsSome, SomeType>

OptionBuilder is a class that represents an optional value: every Option is either Some and contains a value and type, or None which does not any type.

Since

v1.0.0

Type Parameters

IsSome extends boolean
SomeType = unknown

Implements

IOptionImplementation<IsSome, SomeType>

Index

Constructors

constructor

new OptionBuilder<IsSome extends boolean, SomeType = unknown>(
isSome: IsSome,
value: SomeType,
): OptionBuilder<IsSome, SomeType>
Type Parameters
- IsSome extends boolean
- SomeType = unknown
Parameters
- isSome: IsSome
- value: SomeType
Returns OptionBuilder<IsSome, SomeType>
- Defined in src/option/OptionInstance.mts:14

Accessors

isNone

get isNone(): MappedType<IsSome, false, true>
Returns true if the option is a None value.

Returns MappedType<IsSome, false, true>
Example
```
Some(2).isNone // false
None<number>().isNone // true
```
Implementation of IOptionImplementation.isNone
- Defined in src/option/OptionInstance.mts:23

isSome

get isSome(): MappedType<IsSome, true, false>
Returns true if the option is a Some value.

Returns MappedType<IsSome, true, false>
Example
```
Some(2).isSome // true
None<number>().isSome // false
```
Implementation of IOptionImplementation.isSome
- Defined in src/option/OptionInstance.mts:19

Methods

and

and<CompareType>(
value: IOption<CompareType>,
): MappedType<IsSome, IOption<CompareType>, OptionBuilder<IsSome, SomeType>>
Method to compare two Options with and operation
Type Parameters
- CompareType
Parameters
- value: IOption<CompareType>
  other Option to compare
Returns MappedType<IsSome, IOption<CompareType>, OptionBuilder<IsSome, SomeType>>
See
https://doc.rust-lang.org/std/option/enum.Option.html#method.and
Example
```
Some(2).and(Some(3)) // Some(3)
None().and(Some(3)) // None()
Some(2).and(None()) // None()
None().and(None()) // None()
```
Implementation of IOptionImplementation.and
- Defined in src/option/OptionInstance.mts:86

andThen

andThen<CompareType, OverrideType = unknown>(
    callbackFunc: (
        value: MappedType<IsSome, SomeType, OverrideType>,
    ) => IOption<CompareType>,
): MappedType<IsSome, IOption<CompareType>, OptionBuilder<IsSome, SomeType>>
Method to compare two Options with andThen operation
Type Parameters
- CompareType
- OverrideType = unknown
Parameters
- callbackFunc: (value: MappedType<IsSome, SomeType, OverrideType>) => IOption<CompareType>
  function to return default value
Returns MappedType<IsSome, IOption<CompareType>, OptionBuilder<IsSome, SomeType>>
See
https://doc.rust-lang.org/std/option/enum.Option.html#method.and_then
Example
```
Some(2).andThen((val) => Some(val + 1)) // Some(3)
None().andThen<number>((val) => Some(val + 1)) // None()
```
Implementation of IOptionImplementation.andThen
- Defined in src/option/OptionInstance.mts:90

cloned

cloned(): OptionBuilder<IsSome, SomeType>
Method to clone an Option

Returns OptionBuilder<IsSome, SomeType>
- cloned Option instance
Example
```
const x = Some(2);
const y = x.clone();
```
Implementation of IOptionImplementation.cloned
- Defined in src/option/OptionInstance.mts:27

eq

eq(other: IOption): boolean
Compare two Options
Parameters
- other: IOption
Returns boolean
Implementation of IOptionImplementation.eq
- Defined in src/option/OptionInstance.mts:68

expect

expect(error: string | Error): MappedType<IsSome, SomeType, never>
expect the Option to be Some or throw an error
Parameters
- error: string | Error
Returns MappedType<IsSome, SomeType, never>
Example
```
Some(2).expect('error message') // 2
None().expect('error message') // throws new Error('error message')
```
Implementation of IOptionImplementation.expect
- Defined in src/option/OptionInstance.mts:118

getOrInsert

getOrInsert(value: SomeType): SomeType
Method to get the value or insert a new value
Parameters
- value: SomeType
  value to insert if None
Returns SomeType
See
https://doc.rust-lang.org/std/option/enum.Option.html#method.get_or_insert
Example
```
Some(2).getOrInsert(3) // 2
None().getOrInsert(3) // 3
```
Implementation of IOptionImplementation.getOrInsert
- Defined in src/option/OptionInstance.mts:97

insert

insert(value: SomeType): SomeType
Inserts value into Option.
Parameters
- value: SomeType
  new value
Returns SomeType
currently set value

See
https://doc.rust-lang.org/std/option/enum.Option.html#method.insert
Implementation of IOptionImplementation.insert
- Defined in src/option/OptionInstance.mts:31

map

map<NewType>(
fn: (value: SomeType) => NewType,
): MappedType<IsSome, ISome<NewType>, INone<NewType>>
Map the Option value to a new value if Some
Type Parameters
- NewType
Parameters
- fn: (value: SomeType) => NewType
Returns MappedType<IsSome, ISome<NewType>, INone<NewType>>
Example
```
Some("text").map((v)=> Buffer.from(v)) // Some<Buffer>
None<string>().map((v)=> Buffer.from(v)) // None<Buffer>
```
Since
v1.0.4
Implementation of IOptionImplementation.map
- Defined in src/option/OptionInstance.mts:112

match

match<Output>(
solver: OptionMatchSolver<SomeType, Output>,
defaultValue?: Output,
): undefined | Output
Match the Option value with a solver
Type Parameters
- Output
Parameters
- solver: OptionMatchSolver<SomeType, Output>
  solver to match the value (Map key to match, callback as resolver)
- OptionaldefaultValue: Output
  default value if no match
Returns undefined | Output
See
https://doc.rust-lang.org/std/option/enum.Option.html#method.match
Example
```
Some(1).match(
  new Map([
    [1, () => 'one'],
    [2, () => 'two'],
  ]),
  'other', // default value
); // 'one'
None().match(
  new Map([
    [1, () => 'one'],
    [2, () => 'two'],
  ]),
  'other', // default value
); // 'other'
```
Implementation of IOptionImplementation.match
- Defined in src/option/OptionInstance.mts:101
match<Output>(
solver: OptionMatchSolver<SomeType, Output>,
defaultValue: Output,
): Output
Type Parameters
- Output
Parameters
- solver: OptionMatchSolver<SomeType, Output>
- defaultValue: Output
Returns Output
Implementation of IOptionImplementation.match
- Defined in src/option/OptionInstance.mts:102

or

or<ValueType>(
value: IOption<ValueType>,
): MappedType<IsSome, OptionBuilder<IsSome, SomeType>, IOption<ValueType>>
Method to compare two Options with or operation
Type Parameters
- ValueType
Parameters
- value: IOption<ValueType>
  other Option to compare
Returns MappedType<IsSome, OptionBuilder<IsSome, SomeType>, IOption<ValueType>>
See
https://doc.rust-lang.org/std/option/enum.Option.html#method.or
Example
```
Some(2).or(Some(3)) // Some(2)
None().or(Some(3)) // Some(3)
```
Implementation of IOptionImplementation.or
- Defined in src/option/OptionInstance.mts:78

orElse

orElse<ValueType>(
callbackFunc: (value: SomeType) => IOption<ValueType>,
): MappedType<IsSome, OptionBuilder<IsSome, SomeType>, IOption<ValueType>>
Method to compare two Options with or operation
Type Parameters
- ValueType
Parameters
- callbackFunc: (value: SomeType) => IOption<ValueType>
  function to return default value
Returns MappedType<IsSome, OptionBuilder<IsSome, SomeType>, IOption<ValueType>>
See
https://doc.rust-lang.org/std/option/enum.Option.html#method.or_else
Example
```
Some(2).orElse(() => Some(3)) // Some(2)
None().orElse(() => Some(3)) // Some(3)
```
Implementation of IOptionImplementation.orElse
- Defined in src/option/OptionInstance.mts:82

replace

replace(value: SomeType): OptionBuilder<IsSome, SomeType>
Replace the actual value with the given one and returns the old Option.

Warning: currently TS can't change type of "this" (with asserts) and return value at the same time. https://github.com/microsoft/TypeScript/issues/41339
Parameters
- value: SomeType
  new value
Returns OptionBuilder<IsSome, SomeType>
old Option

See
https://doc.rust-lang.org/std/option/enum.Option.html#method.replace
Implementation of IOptionImplementation.replace
- Defined in src/option/OptionInstance.mts:39

take

take(): OptionBuilder<IsSome, undefined | SomeType>
Returns the contained Some value, consuming the self value.

Warning: currently TS can't change type of "this" (with asserts) and return value at the same time. https://github.com/microsoft/TypeScript/issues/41339

Returns OptionBuilder<IsSome, undefined | SomeType>
copy of original Option
Example
```
const x = Some(2);
const y = x.take();
console.log(x.isNone); // true
console.log(y.isSome); // true
```
Implementation of IOptionImplementation.take
- Defined in src/option/OptionInstance.mts:35

toJSON

toJSON(): MappedType<IsSome, IJsonSome<SomeType>, IJsonNone>
Convert Option to JSON

Returns MappedType<IsSome, IJsonSome<SomeType>, IJsonNone>
JSON
Example
```
Some(2).toJSON() // {$class: 'Option::Some', value: 2}
None().toJSON() // {$class: 'Option::None'}
```
Implementation of IOptionImplementation.toJSON
- Defined in src/option/OptionInstance.mts:129

toResult

toResult<ErrType>(
err: ErrType,
): MappedType<IsSome, IOk<SomeType>, IErr<ErrType>>
Convert Option to Result and discard the error type
Type Parameters
- ErrType
Parameters
- err: ErrType
Returns MappedType<IsSome, IOk<SomeType>, IErr<ErrType>>
Result
Example
```
Some(2).toResult() // Ok<number>(2)
None().toResult() // Err<never>()
```
Implementation of IOptionImplementation.toResult
- Defined in src/option/OptionInstance.mts:125

toString

toString(): MappedType<IsSome, `Some(${string})`, "None()">
Convert Option to string

Returns MappedType<IsSome, `Some(${string})`, "None()">
string representation of the Option
Example
```
Some(2).toString() // 'Some(2)'
None().toString() // 'None()'
```
Implementation of IOptionImplementation.toString
- Defined in src/option/OptionInstance.mts:133

unwrap

unwrap(
err?: Error | ((err: Error) => Error),
): MappedType<IsSome, SomeType, never>
Method to unwrap the value or throw an error if None
Parameters
- Optionalerr: Error | ((err: Error) => Error)
  optional error or function to transform the error
Returns MappedType<IsSome, SomeType, never>
See
https://doc.rust-lang.org/std/option/enum.Option.html#method.unwrap
Example
```
Some(2).unwrap() // 2
None<number>().unwrap() // throws Error
```
Implementation of IOptionImplementation.unwrap
- Defined in src/option/OptionInstance.mts:45

unwrapOr

unwrapOr<DefType>(def: DefType): MappedType<IsSome, SomeType, DefType>
Method to unwrap the value or if None then return the default value.
Type Parameters
- DefType
Parameters
- def: DefType
Returns MappedType<IsSome, SomeType, DefType>
See
https://doc.rust-lang.org/std/option/enum.Option.html#method.unwrap_or
Example
```
Some(2).unwrapOr(3) // 2
None<number>().unwrapOr(3) // 3
```
Implementation of IOptionImplementation.unwrapOr
- Defined in src/option/OptionInstance.mts:56

unwrapOrElse

unwrapOrElse<DefType>(fn: () => DefType): MappedType<IsSome, SomeType, DefType>
Method to unwrap the value or if None then return the default value from function.
Type Parameters
- DefType
Parameters
- fn: () => DefType
  function to return default value
Returns MappedType<IsSome, SomeType, DefType>
See
https://doc.rust-lang.org/std/option/enum.Option.html#method.unwrap_or_else
Example
```
Some(2).unwrapOrElse(() => 3) // 2
None<number>().unwrapOrElse(() => 3) // 3
```
Implementation of IOptionImplementation.unwrapOrElse
- Defined in src/option/OptionInstance.mts:60

unwrapOrValueOf

unwrapOrValueOf<DefType>(
BaseConstructor: ConstructorWithValueOf<DefType>,
): MappedType<IsSome, SomeType, DefType>
Method to unwrap the value or if None then return the default value from constructors valueOf (mimic Rust unwrap_or_default).
Type Parameters
- DefType
Parameters
- BaseConstructor: ConstructorWithValueOf<DefType>
  constructor to return default value from valueOf
Returns MappedType<IsSome, SomeType, DefType>
See
https://doc.rust-lang.org/std/option/enum.Option.html#method.unwrap_or_default
Example
```
Some(2).unwrapOrValueOf(Number) // 2
None<number>().unwrapOrValueOf(Number) // 0
```
Implementation of IOptionImplementation.unwrapOrValueOf
- Defined in src/option/OptionInstance.mts:64

Class OptionBuilder<IsSome, SomeType>

Since

Type Parameters

Implements

Index

Constructors

Accessors

Methods

Constructors

constructor

Type Parameters

Parameters

Returns OptionBuilder<IsSome, SomeType>

Accessors

isNone

Returns MappedType<IsSome, false, true>

Example

isSome

Returns MappedType<IsSome, true, false>

Example

Methods

and

Type Parameters

Parameters

Returns MappedType<IsSome, IOption<CompareType>, OptionBuilder<IsSome, SomeType>>

See

Example

andThen

Type Parameters

Parameters

Returns MappedType<IsSome, IOption<CompareType>, OptionBuilder<IsSome, SomeType>>

See

Example

cloned

Returns OptionBuilder<IsSome, SomeType>

Example

eq

Parameters

Returns boolean

expect

Parameters

Returns MappedType<IsSome, SomeType, never>

Example

getOrInsert

Parameters

Returns SomeType

See

Example

insert

Parameters

Returns SomeType

See

map

Type Parameters

Parameters

Returns MappedType<IsSome, ISome<NewType>, INone<NewType>>

Example

Since

match

Type Parameters

Parameters

Returns undefined | Output

See

Example

Type Parameters

Parameters

Returns Output

or

Type Parameters

Parameters

Returns MappedType<IsSome, OptionBuilder<IsSome, SomeType>, IOption<ValueType>>

See

Example

orElse

Type Parameters

Parameters

Returns MappedType<IsSome, OptionBuilder<IsSome, SomeType>, IOption<ValueType>>

See

Example

replace