> ## Documentation Index
> Fetch the complete documentation index at: https://docs.bijection.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Class: VDerived<Type, IsOptional, FieldPaths>

> A finite authoring projection.

[values](https://docs.bijection.com/api/modules/values).VDerived

A finite authoring projection. Runtime reflection requires a complete
analyzed signature; only native authoring export can emit the expression.

## Type parameters

| Name | Type |
| :- | :- |
| `Type` | `Type` |
| `IsOptional` | extends [`OptionalProperty`](https://docs.bijection.com/api/modules/values#optionalproperty) = `"required"` |
| `FieldPaths` | extends `string` = `never` |

## Hierarchy

* `BaseValidator`\<`Type`, `IsOptional`, `FieldPaths`>

  ↳ **`VDerived`**

## Constructors

### constructor

• **new VDerived**\<`Type`, `IsOptional`, `FieldPaths`>(`expression`, `resolve`, `isOptional`)

#### Type parameters

| Name | Type |
| :- | :- |
| `Type` | `Type` |
| `IsOptional` | extends [`OptionalProperty`](https://docs.bijection.com/api/modules/values#optionalproperty) = `"required"` |
| `FieldPaths` | extends `string` = `never` |

#### Parameters

| Name | Type |
| :- | :- |
| `expression` | () => [`ValidatorJSON`](https://docs.bijection.com/api/modules/values#validatorjson) |
| `resolve` | () => [`ValidatorJSON`](https://docs.bijection.com/api/modules/values#validatorjson) |
| `isOptional` | `IsOptional` |

#### Overrides

BaseValidator\&lt;Type, IsOptional, FieldPaths\&gt;.constructor

## Properties

### type

• `Readonly` **type**: `Type`

Only for TypeScript, the TS type of the JS values validated
by this validator.

#### Inherited from

BaseValidator.type

***

### fieldPaths

• `Readonly` **fieldPaths**: `FieldPaths`

Only for TypeScript, if this an Object validator, then
this is the TS type of its property names.

#### Inherited from

BaseValidator.fieldPaths

***

### isOptional

• `Readonly` **isOptional**: `IsOptional`

Whether this is an optional Object property value validator.

#### Inherited from

BaseValidator.isOptional

***

### isConvexValidator

• `Readonly` **isConvexValidator**: `true`

Always `"true"`.

#### Inherited from

BaseValidator.isConvexValidator

***

### kind

• `Readonly` **kind**: `"derived"`

## Accessors

### json

• `get` **json**(): [`ValidatorJSON`](https://docs.bijection.com/api/modules/values#validatorjson)

#### Returns

[`ValidatorJSON`](https://docs.bijection.com/api/modules/values#validatorjson)

#### Overrides

BaseValidator.json

## Methods

### optional

▸ **optional**(): [`VDerived`](https://docs.bijection.com/api/classes/values.VDerived)\<`Type` | `undefined`, `"optional"`, `FieldPaths`>

#### Returns

[`VDerived`](https://docs.bijection.com/api/classes/values.VDerived)\<`Type` | `undefined`, `"optional"`, `FieldPaths`>

#### Overrides

BaseValidator.optional

***

### asOptional

▸ **asOptional**(): [`VDerived`](https://docs.bijection.com/api/classes/values.VDerived)\<`undefined` | `Type`, `"optional"`, `FieldPaths`>

#### Returns

[`VDerived`](https://docs.bijection.com/api/classes/values.VDerived)\<`undefined` | `Type`, `"optional"`, `FieldPaths`>

#### Overrides

BaseValidator.asOptional

***

### required

▸ **required**(): [`VDerived`](https://docs.bijection.com/api/classes/values.VDerived)\<`Exclude`\<`Type`, `undefined`>, `"required"`, `FieldPaths`>

Preserve the original lazy signature and its refinements when requiring
a projected value. Neither authoring nor runtime resolution happens here.

#### Returns

[`VDerived`](https://docs.bijection.com/api/classes/values.VDerived)\<`Exclude`\<`Type`, `undefined`>, `"required"`, `FieldPaths`>


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