Guard overview

This module is experimental

Experimental features are published in order to get early feedback from the community, see these tracking issues for further discussions and enhancements.

A feature tagged as Experimental is in a high state of flux, you’re at risk of it changing without notice.

Added in v2.2.0

---

Table of contents

• combinators
  • alt
  • array
  • compose
  • id
  • intersect
  • lazy
  • nullable
  • partial
  • readonly
  • record
  • refine
  • struct
  • sum
  • tuple
  • union
  • zero
  • type
• constructors
  • literal
• instances
  • Schemable
  • URI
  • URI (type alias)
  • WithRefine
  • WithUnion
  • WithUnknownContainers
• model
  • Guard (interface)
• primitives
  • UnknownArray
  • UnknownRecord
  • boolean
  • number
  • string
• utils
  • InputOf (type alias)
  • TypeOf (type alias)

---

combinators

alt

Signature

export declare const alt: <I, A extends I>(that: () => Guard<I, A>) => (me: Guard<I, A>) => Guard<I, A>

Added in v2.2.8

array

Signature

export declare const array: <A>(item: Guard<unknown, A>) => Guard<unknown, A[]>

Added in v2.2.0

compose

Signature

export declare const compose: <I, A extends I, B extends A>(to: Guard<A, B>) => (from: Guard<I, A>) => Guard<I, B>

Added in v2.2.8

id

Signature

export declare const id: <A>() => Guard<A, A>

Added in v2.2.8

intersect

Signature

export declare const intersect: <B>(right: Guard<unknown, B>) => <A>(left: Guard<unknown, A>) => Guard<unknown, A & B>

Added in v2.2.0

lazy

Signature

export declare const lazy: <A>(f: () => Guard<unknown, A>) => Guard<unknown, A>

Added in v2.2.0

nullable

Signature

export declare const nullable: <I, A extends I>(or: Guard<I, A>) => Guard<I | null, A | null>

Added in v2.2.0

partial

Signature

export declare const partial: <A>(properties: { [K in keyof A]: Guard<unknown, A[K]> }) => Guard<
  unknown,
  Partial<{ [K in keyof A]: A[K] }>
>

Added in v2.2.0

readonly

Signature

export declare const readonly: <I, A extends I>(guard: Guard<I, A>) => Guard<I, Readonly<A>>

Added in v2.2.15

record

Signature

export declare const record: <A>(codomain: Guard<unknown, A>) => Guard<unknown, Record<string, A>>

Added in v2.2.0

refine

Signature

export declare const refine: <I, A extends I, B extends A>(
  refinement: Refinement<A, B>
) => (from: Guard<I, A>) => Guard<I, B>

Added in v2.2.0

struct

Signature

export declare const struct: <A>(properties: { [K in keyof A]: Guard<unknown, A[K]> }) => Guard<
  unknown,
  { [K in keyof A]: A[K] }
>

Added in v2.2.15

sum

Signature

export declare const sum: <T extends string>(
  tag: T
) => <A>(members: { [K in keyof A]: Guard<unknown, A[K] & Record<T, K>> }) => Guard<unknown, A[keyof A]>

Added in v2.2.0

tuple

Signature

export declare const tuple: <A extends readonly unknown[]>(
  ...components: { [K in keyof A]: Guard<unknown, A[K]> }
) => Guard<unknown, A>

Added in v2.2.0

union

Signature

export declare const union: <A extends readonly [unknown, ...unknown[]]>(
  ...members: { [K in keyof A]: Guard<unknown, A[K]> }
) => Guard<unknown, A[number]>

Added in v2.2.0

zero

Signature

export declare const zero: <I, A extends I>() => Guard<I, A>

Added in v2.2.8

type

Use struct instead.

Signature

export declare const type: <A>(properties: { [K in keyof A]: Guard<unknown, A[K]> }) => Guard<
  unknown,
  { [K in keyof A]: A[K] }
>

Added in v2.2.0

constructors

literal

Signature

export declare const literal: <A extends readonly [L, ...L[]], L extends S.Literal = S.Literal>(
  ...values: A
) => Guard<unknown, A[number]>

Added in v2.2.0

instances

Schemable

Signature

export declare const Schemable: S.Schemable1<'io-ts/Guard'>

Added in v2.2.8

URI

Signature

export declare const URI: 'io-ts/Guard'

Added in v2.2.0

URI (type alias)

Signature

export type URI = typeof URI

Added in v2.2.0

WithRefine

Signature

export declare const WithRefine: S.WithRefine1<'io-ts/Guard'>

Added in v2.2.8

WithUnion

Signature

export declare const WithUnion: S.WithUnion1<'io-ts/Guard'>

Added in v2.2.8

WithUnknownContainers

Signature

export declare const WithUnknownContainers: S.WithUnknownContainers1<'io-ts/Guard'>

Added in v2.2.8

model

Guard (interface)

Signature

export interface Guard<I, A extends I> {
  is: (i: I) => i is A
}

Added in v2.2.8

primitives

UnknownArray

Signature

export declare const UnknownArray: Guard<unknown, unknown[]>

Added in v2.2.0

UnknownRecord

Signature

export declare const UnknownRecord: Guard<unknown, Record<string, unknown>>

Added in v2.2.0

boolean

Signature

export declare const boolean: Guard<unknown, boolean>

Added in v2.2.0

number

Note: NaN is excluded.

Signature

export declare const number: Guard<unknown, number>

Added in v2.2.0

string

Signature

export declare const string: Guard<unknown, string>

Added in v2.2.0

utils

InputOf (type alias)

Signature

export type InputOf<G> = G extends Guard<infer I, any> ? I : never

Added in v2.2.8

TypeOf (type alias)

Signature

export type TypeOf<G> = G extends Guard<any, infer A> ? A : never

Added in v2.2.2