effect-io-ai

Package: effect
Module: Match

Match.Matcher

Pattern matching follows a structured process:

• Creating a matcher: Define a Matcher that operates on either a specific Match.type or Match.value.

• Defining patterns: Use combinators such as Match.when, Match.not, and Match.tag to specify matching conditions.

• Completing the match: Apply a finalizer such as Match.exhaustive, Match.orElse, or Match.option to determine how unmatched cases should be handled.

Example

import { Match } from "effect"

// Simulated dynamic input that can be a string or a number
const input: string | number = "some input"

//      ┌─── string
//      ▼
const result = Match.value(input).pipe(
  // Match if the value is a number
  Match.when(Match.number, (n) => `number: ${n}`),
  // Match if the value is a string
  Match.when(Match.string, (s) => `string: ${s}`),
  // Ensure all possible cases are covered
  Match.exhaustive
)

console.log(result)
// Output: "string: some input"

Signature

type Matcher<Input, Filters, RemainingApplied, Result, Provided, Return> = | TypeMatcher<Input, Filters, RemainingApplied, Result, Return>
  | ValueMatcher<Input, Filters, RemainingApplied, Result, Provided, Return>

Source

Since v1.0.0