(self: string, that: string): booleanProvides an Equivalence instance for strings using strict equality (===).
Example (Comparing strings for equality)
import { String } from "effect"
console.log(String.Equivalence("hello", "hello")) // true
console.log(String.Equivalence("hello", "world")) // falseinstances
Source effect/String.ts:961 lines
export const const Equivalence: Equ.Equivalence<string>Provides an Equivalence instance for strings using strict equality (===).
Example (Comparing strings for equality)
import { String } from "effect"
console.log(String.Equivalence("hello", "hello")) // true
console.log(String.Equivalence("hello", "world")) // false
Equivalence: import EquEqu.type Equivalence<in A> = (
self: A,
that: A
) => boolean
Represents an equivalence relation over type A.
When to use
Use as a type annotation when you accept or return an equivalence function.
Details
- Returns
boolean: true if values are equivalent, false otherwise
- Must satisfy reflexive, symmetric, and transitive properties
Example (Defining simple number equivalence)
import type { Equivalence } from "effect"
const numberEq: Equivalence.Equivalence<number> = (a, b) => a === b
console.log(numberEq(1, 1)) // true
console.log(numberEq(1, 2)) // false
Example (Defining custom object equivalence)
import type { Equivalence } from "effect"
interface Point {
x: number
y: number
}
const pointEq: Equivalence.Equivalence<Point> = (a, b) =>
a.x === b.x && a.y === b.y
console.log(pointEq({ x: 1, y: 2 }, { x: 1, y: 2 })) // true
Equivalence<string> = import EquEqu.const String: Equivalence<string>Equivalence instance for strings using strict equality (===).
When to use
Use when you need to supply case-sensitive string equality.
Example (Comparing strings)
import { Equivalence } from "effect"
console.log(Equivalence.String("hello", "hello")) // true
console.log(Equivalence.String("hello", "world")) // false
String