effect-io-ai

Package: effect
Module: Match

Match.value

Creates a matcher from a specific value.

Details

This function allows you to define a Matcher directly from a given value, rather than from a type. This is useful when working with known values, enabling structured pattern matching on objects, primitives, or any data structure.

Once the matcher is created, you can use pattern-matching functions like when to define how different cases should be handled.

Example (Matching an Object by Property)

import { Match } from "effect"

const input = { name: "John", age: 30 }

// Create a matcher for the specific object
const result = Match.value(input).pipe(
  // Match when the 'name' property is "John"
  Match.when(
    { name: "John" },
    (user) => `${user.name} is ${user.age} years old`
  ),
  // Provide a fallback if no match is found
  Match.orElse(() => "Oh, not John")
)

console.log(result)
// Output: "John is 30 years old"

See

• type for creating a matcher from a specific type.

Signature

declare const value: <const I>(i: I) => Matcher<I, Types.Without<never>, I, never, I>

Source

Since v1.0.0