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Shifted/node_modules/effect/dist/dts/Predicate.d.ts
2026-02-10 01:14:19 +00:00

2197 lines
72 KiB
TypeScript

import type { TypeLambda } from "./HKT.js";
import type { TupleOf, TupleOfAtLeast } from "./Types.js";
/**
* Represents a function that takes a value of type `A` and returns `true` if the value
* satisfies some condition, `false` otherwise.
*
* @example
* ```ts
* import { Predicate } from "effect"
* import * as assert from "node:assert"
*
* const isEven: Predicate.Predicate<number> = (n) => n % 2 === 0
*
* assert.strictEqual(isEven(2), true)
* assert.strictEqual(isEven(3), false)
* ```
*
* @category models
* @since 2.0.0
*/
export interface Predicate<in A> {
(a: A): boolean;
}
/**
* A `TypeLambda` for `Predicate`. This is used to support higher-kinded types
* and allows `Predicate` to be used in generic contexts within the `effect` ecosystem.
*
* @category type lambdas
* @since 2.0.0
*/
export interface PredicateTypeLambda extends TypeLambda {
readonly type: Predicate<this["Target"]>;
}
/**
* Represents a function that serves as a type guard.
*
* A `Refinement<A, B>` is a function that takes a value of type `A` and returns a
* type predicate `a is B`, where `B` is a subtype of `A`. If the function returns
* `true`, TypeScript will narrow the type of the input variable to `B`.
*
* @example
* ```ts
* import { Predicate } from "effect"
* import * as assert from "node:assert"
*
* const isString: Predicate.Refinement<unknown, string> = (u): u is string => typeof u === "string"
*
* const value: unknown = "hello"
*
* if (isString(value)) {
* // value is now known to be a string
* assert.strictEqual(value.toUpperCase(), "HELLO")
* }
* ```
*
* @category models
* @since 2.0.0
*/
export interface Refinement<in A, out B extends A> {
(a: A): a is B;
}
/**
* A namespace for type-level utilities for `Predicate`.
*
* @since 3.6.0
* @category type-level
*/
export declare namespace Predicate {
/**
* Extracts the input type `A` from a `Predicate<A>`.
*
* @example
* ```ts
* import { type Predicate } from "effect"
*
* type T = Predicate.Predicate.In<Predicate.Predicate<string>> // T is string
* ```
*
* @since 3.6.0
* @category type-level
*/
type In<T extends Any> = [T] extends [Predicate<infer _A>] ? _A : never;
/**
* A type representing any `Predicate`.
*
* @since 3.6.0
* @category type-level
*/
type Any = Predicate<never>;
}
/**
* A namespace for type-level utilities for `Refinement`.
*
* @since 3.6.0
* @category type-level
*/
export declare namespace Refinement {
/**
* Extracts the input type `A` from a `Refinement<A, B>`.
*
* @example
* ```ts
* import { type Predicate } from "effect"
*
* type IsString = Predicate.Refinement<unknown, string>
* type T = Predicate.Refinement.In<IsString> // T is unknown
* ```
*
* @since 3.6.0
* @category type-level
*/
type In<T extends Any> = [T] extends [Refinement<infer _A, infer _>] ? _A : never;
/**
* Extracts the output (refined) type `B` from a `Refinement<A, B>`.
*
* @example
* ```ts
* import { type Predicate } from "effect"
*
* type IsString = Predicate.Refinement<unknown, string>
* type T = Predicate.Refinement.Out<IsString> // T is string
* ```
*
* @since 3.6.0
* @category type-level
*/
type Out<T extends Any> = [T] extends [Refinement<infer _, infer _B>] ? _B : never;
/**
* A type representing any `Refinement`.
*
* @since 3.6.0
* @category type-level
*/
type Any = Refinement<any, any>;
}
/**
* Transforms a `Predicate<A>` into a `Predicate<B>` by applying a function `(b: B) => A`
* to the input before passing it to the predicate. This is also known as "contramap" or
* "pre-composition".
*
* @example
* ```ts
* import { Predicate, Number } from "effect"
* import * as assert from "node:assert"
*
* // A predicate on numbers
* const isPositive: Predicate.Predicate<number> = Number.greaterThan(0)
*
* // A function from `string` to `number`
* const stringLength = (s: string): number => s.length
*
* // Create a new predicate on strings by mapping the input
* const hasPositiveLength = Predicate.mapInput(isPositive, stringLength)
*
* assert.strictEqual(hasPositiveLength("hello"), true)
* assert.strictEqual(hasPositiveLength(""), false)
* ```
*
* @category combinators
* @since 2.0.0
*/
export declare const mapInput: {
/**
* Transforms a `Predicate<A>` into a `Predicate<B>` by applying a function `(b: B) => A`
* to the input before passing it to the predicate. This is also known as "contramap" or
* "pre-composition".
*
* @example
* ```ts
* import { Predicate, Number } from "effect"
* import * as assert from "node:assert"
*
* // A predicate on numbers
* const isPositive: Predicate.Predicate<number> = Number.greaterThan(0)
*
* // A function from `string` to `number`
* const stringLength = (s: string): number => s.length
*
* // Create a new predicate on strings by mapping the input
* const hasPositiveLength = Predicate.mapInput(isPositive, stringLength)
*
* assert.strictEqual(hasPositiveLength("hello"), true)
* assert.strictEqual(hasPositiveLength(""), false)
* ```
*
* @category combinators
* @since 2.0.0
*/
<B, A>(f: (b: B) => A): (self: Predicate<A>) => Predicate<B>;
/**
* Transforms a `Predicate<A>` into a `Predicate<B>` by applying a function `(b: B) => A`
* to the input before passing it to the predicate. This is also known as "contramap" or
* "pre-composition".
*
* @example
* ```ts
* import { Predicate, Number } from "effect"
* import * as assert from "node:assert"
*
* // A predicate on numbers
* const isPositive: Predicate.Predicate<number> = Number.greaterThan(0)
*
* // A function from `string` to `number`
* const stringLength = (s: string): number => s.length
*
* // Create a new predicate on strings by mapping the input
* const hasPositiveLength = Predicate.mapInput(isPositive, stringLength)
*
* assert.strictEqual(hasPositiveLength("hello"), true)
* assert.strictEqual(hasPositiveLength(""), false)
* ```
*
* @category combinators
* @since 2.0.0
*/
<A, B>(self: Predicate<A>, f: (b: B) => A): Predicate<B>;
};
/**
* A refinement that checks if a `ReadonlyArray<T>` is a tuple with exactly `N` elements.
* If the check is successful, the type is narrowed to `TupleOf<N, T>`.
*
* @example
* ```ts
* import * as assert from "node:assert"
* import { isTupleOf } from "effect/Predicate"
*
* const isTupleOf3 = isTupleOf(3)
*
* assert.strictEqual(isTupleOf3([1, 2, 3]), true);
* assert.strictEqual(isTupleOf3([1, 2]), false);
*
* const arr: number[] = [1, 2, 3];
* if (isTupleOf(arr, 3)) {
* // The type of arr is now [number, number, number]
* const [a, b, c] = arr;
* assert.deepStrictEqual([a, b, c], [1, 2, 3])
* }
* ```
*
* @category guards
* @since 3.3.0
*/
export declare const isTupleOf: {
/**
* A refinement that checks if a `ReadonlyArray<T>` is a tuple with exactly `N` elements.
* If the check is successful, the type is narrowed to `TupleOf<N, T>`.
*
* @example
* ```ts
* import * as assert from "node:assert"
* import { isTupleOf } from "effect/Predicate"
*
* const isTupleOf3 = isTupleOf(3)
*
* assert.strictEqual(isTupleOf3([1, 2, 3]), true);
* assert.strictEqual(isTupleOf3([1, 2]), false);
*
* const arr: number[] = [1, 2, 3];
* if (isTupleOf(arr, 3)) {
* // The type of arr is now [number, number, number]
* const [a, b, c] = arr;
* assert.deepStrictEqual([a, b, c], [1, 2, 3])
* }
* ```
*
* @category guards
* @since 3.3.0
*/
<N extends number>(n: N): <T>(self: ReadonlyArray<T>) => self is TupleOf<N, T>;
/**
* A refinement that checks if a `ReadonlyArray<T>` is a tuple with exactly `N` elements.
* If the check is successful, the type is narrowed to `TupleOf<N, T>`.
*
* @example
* ```ts
* import * as assert from "node:assert"
* import { isTupleOf } from "effect/Predicate"
*
* const isTupleOf3 = isTupleOf(3)
*
* assert.strictEqual(isTupleOf3([1, 2, 3]), true);
* assert.strictEqual(isTupleOf3([1, 2]), false);
*
* const arr: number[] = [1, 2, 3];
* if (isTupleOf(arr, 3)) {
* // The type of arr is now [number, number, number]
* const [a, b, c] = arr;
* assert.deepStrictEqual([a, b, c], [1, 2, 3])
* }
* ```
*
* @category guards
* @since 3.3.0
*/
<T, N extends number>(self: ReadonlyArray<T>, n: N): self is TupleOf<N, T>;
};
/**
* A refinement that checks if a `ReadonlyArray<T>` is a tuple with at least `N` elements.
* If the check is successful, the type is narrowed to `TupleOfAtLeast<N, T>`.
*
* @example
* ```ts
* import * as assert from "node:assert"
* import { isTupleOfAtLeast } from "effect/Predicate"
*
* const isTupleOfAtLeast3 = isTupleOfAtLeast(3)
*
* assert.strictEqual(isTupleOfAtLeast3([1, 2, 3]), true);
* assert.strictEqual(isTupleOfAtLeast3([1, 2, 3, 4]), true);
* assert.strictEqual(isTupleOfAtLeast3([1, 2]), false);
*
* const arr: number[] = [1, 2, 3, 4];
* if (isTupleOfAtLeast(arr, 3)) {
* // The type of arr is now [number, number, number, ...number[]]
* const [a, b, c] = arr;
* assert.deepStrictEqual([a, b, c], [1, 2, 3])
* }
* ```
*
* @category guards
* @since 3.3.0
*/
export declare const isTupleOfAtLeast: {
/**
* A refinement that checks if a `ReadonlyArray<T>` is a tuple with at least `N` elements.
* If the check is successful, the type is narrowed to `TupleOfAtLeast<N, T>`.
*
* @example
* ```ts
* import * as assert from "node:assert"
* import { isTupleOfAtLeast } from "effect/Predicate"
*
* const isTupleOfAtLeast3 = isTupleOfAtLeast(3)
*
* assert.strictEqual(isTupleOfAtLeast3([1, 2, 3]), true);
* assert.strictEqual(isTupleOfAtLeast3([1, 2, 3, 4]), true);
* assert.strictEqual(isTupleOfAtLeast3([1, 2]), false);
*
* const arr: number[] = [1, 2, 3, 4];
* if (isTupleOfAtLeast(arr, 3)) {
* // The type of arr is now [number, number, number, ...number[]]
* const [a, b, c] = arr;
* assert.deepStrictEqual([a, b, c], [1, 2, 3])
* }
* ```
*
* @category guards
* @since 3.3.0
*/
<N extends number>(n: N): <T>(self: ReadonlyArray<T>) => self is TupleOfAtLeast<N, T>;
/**
* A refinement that checks if a `ReadonlyArray<T>` is a tuple with at least `N` elements.
* If the check is successful, the type is narrowed to `TupleOfAtLeast<N, T>`.
*
* @example
* ```ts
* import * as assert from "node:assert"
* import { isTupleOfAtLeast } from "effect/Predicate"
*
* const isTupleOfAtLeast3 = isTupleOfAtLeast(3)
*
* assert.strictEqual(isTupleOfAtLeast3([1, 2, 3]), true);
* assert.strictEqual(isTupleOfAtLeast3([1, 2, 3, 4]), true);
* assert.strictEqual(isTupleOfAtLeast3([1, 2]), false);
*
* const arr: number[] = [1, 2, 3, 4];
* if (isTupleOfAtLeast(arr, 3)) {
* // The type of arr is now [number, number, number, ...number[]]
* const [a, b, c] = arr;
* assert.deepStrictEqual([a, b, c], [1, 2, 3])
* }
* ```
*
* @category guards
* @since 3.3.0
*/
<T, N extends number>(self: ReadonlyArray<T>, n: N): self is TupleOfAtLeast<N, T>;
};
/**
* A predicate that checks if a value is "truthy" in JavaScript.
* Fails for `false`, `0`, `-0`, `0n`, `""`, `null`, `undefined`, and `NaN`.
*
* @example
* ```ts
* import * as assert from "node:assert"
* import { isTruthy } from "effect/Predicate"
*
* assert.strictEqual(isTruthy(1), true)
* assert.strictEqual(isTruthy("hello"), true)
* assert.strictEqual(isTruthy({}), true)
*
* assert.strictEqual(isTruthy(0), false)
* assert.strictEqual(isTruthy(""), false)
* assert.strictEqual(isTruthy(null), false)
* assert.strictEqual(isTruthy(undefined), false)
* ```
*
* @category guards
* @since 2.0.0
*/
export declare const isTruthy: (input: unknown) => boolean;
/**
* A refinement that checks if a value is a `Set`.
*
* @example
* ```ts
* import * as assert from "node:assert"
* import { isSet } from "effect/Predicate"
*
* assert.strictEqual(isSet(new Set([1, 2])), true)
* assert.strictEqual(isSet(new Set()), true)
*
* assert.strictEqual(isSet({}), false)
* assert.strictEqual(isSet([1, 2]), false)
* ```
*
* @category guards
* @since 2.0.0
*/
export declare const isSet: (input: unknown) => input is Set<unknown>;
/**
* A refinement that checks if a value is a `Map`.
*
* @example
* ```ts
* import * as assert from "node:assert"
* import { isMap } from "effect/Predicate"
*
* assert.strictEqual(isMap(new Map()), true)
*
* assert.strictEqual(isMap({}), false)
* assert.strictEqual(isMap(new Set()), false)
* ```
*
* @category guards
* @since 2.0.0
*/
export declare const isMap: (input: unknown) => input is Map<unknown, unknown>;
/**
* A refinement that checks if a value is a `string`.
*
* @example
* ```ts
* import * as assert from "node:assert"
* import { isString } from "effect/Predicate"
*
* assert.strictEqual(isString("hello"), true)
* assert.strictEqual(isString(""), true)
*
* assert.strictEqual(isString(123), false)
* assert.strictEqual(isString(null), false)
* ```
*
* @category guards
* @since 2.0.0
*/
export declare const isString: (input: unknown) => input is string;
/**
* A refinement that checks if a value is a `number`.
*
* @example
* ```ts
* import * as assert from "node:assert"
* import { isNumber } from "effect/Predicate"
*
* assert.strictEqual(isNumber(123), true)
* assert.strictEqual(isNumber(0), true)
* assert.strictEqual(isNumber(-1.5), true)
* assert.strictEqual(isNumber(NaN), true)
*
* assert.strictEqual(isNumber("123"), false)
* ```
*
* @category guards
* @since 2.0.0
*/
export declare const isNumber: (input: unknown) => input is number;
/**
* A refinement that checks if a value is a `boolean`.
*
* @example
* ```ts
* import * as assert from "node:assert"
* import { isBoolean } from "effect/Predicate"
*
* assert.strictEqual(isBoolean(true), true)
* assert.strictEqual(isBoolean(false), true)
*
* assert.strictEqual(isBoolean("true"), false)
* assert.strictEqual(isBoolean(0), false)
* ```
*
* @category guards
* @since 2.0.0
*/
export declare const isBoolean: (input: unknown) => input is boolean;
/**
* A refinement that checks if a value is a `bigint`.
*
* @example
* ```ts
* import * as assert from "node:assert"
* import { isBigInt } from "effect/Predicate"
*
* assert.strictEqual(isBigInt(1n), true)
*
* assert.strictEqual(isBigInt(1), false)
* assert.strictEqual(isBigInt("1"), false)
* ```
*
* @category guards
* @since 2.0.0
*/
export declare const isBigInt: (input: unknown) => input is bigint;
/**
* A refinement that checks if a value is a `symbol`.
*
* @example
* ```ts
* import * as assert from "node:assert"
* import { isSymbol } from "effect/Predicate"
*
* assert.strictEqual(isSymbol(Symbol.for("a")), true)
*
* assert.strictEqual(isSymbol("a"), false)
* ```
*
* @category guards
* @since 2.0.0
*/
export declare const isSymbol: (input: unknown) => input is symbol;
/**
* A refinement that checks if a value is a `Function`.
*
* @example
* ```ts
* import * as assert from "node:assert"
* import { isFunction } from "effect/Predicate"
*
* assert.strictEqual(isFunction(() => {}), true)
* assert.strictEqual(isFunction(isFunction), true)
*
* assert.strictEqual(isFunction("function"), false)
* ```
*
* @category guards
* @since 2.0.0
*/
export declare const isFunction: (input: unknown) => input is Function;
/**
* A refinement that checks if a value is `undefined`.
*
* @example
* ```ts
* import * as assert from "node:assert"
* import { isUndefined } from "effect/Predicate"
*
* assert.strictEqual(isUndefined(undefined), true)
*
* assert.strictEqual(isUndefined(null), false)
* assert.strictEqual(isUndefined("undefined"), false)
* ```
*
* @category guards
* @since 2.0.0
*/
export declare const isUndefined: (input: unknown) => input is undefined;
/**
* A refinement that checks if a value is not `undefined`.
*
* @example
* ```ts
* import * as assert from "node:assert"
* import { isNotUndefined } from "effect/Predicate"
*
* assert.strictEqual(isNotUndefined(null), true)
* assert.strictEqual(isNotUndefined("value"), true)
*
* assert.strictEqual(isNotUndefined(undefined), false)
* ```
*
* @category guards
* @since 2.0.0
*/
export declare const isNotUndefined: <A>(input: A) => input is Exclude<A, undefined>;
/**
* A refinement that checks if a value is `null`.
*
* @example
* ```ts
* import * as assert from "node:assert"
* import { isNull } from "effect/Predicate"
*
* assert.strictEqual(isNull(null), true)
*
* assert.strictEqual(isNull(undefined), false)
* assert.strictEqual(isNull("null"), false)
* ```
*
* @category guards
* @since 2.0.0
*/
export declare const isNull: (input: unknown) => input is null;
/**
* A refinement that checks if a value is not `null`.
*
* @example
* ```ts
* import * as assert from "node:assert"
* import { isNotNull } from "effect/Predicate"
*
* assert.strictEqual(isNotNull(undefined), true)
* assert.strictEqual(isNotNull("value"), true)
*
* assert.strictEqual(isNotNull(null), false)
* ```
*
* @category guards
* @since 2.0.0
*/
export declare const isNotNull: <A>(input: A) => input is Exclude<A, null>;
/**
* A refinement that always returns `false`. The type is narrowed to `never`.
*
* @example
* ```ts
* import * as assert from "node:assert"
* import { isNever } from "effect/Predicate"
*
* assert.strictEqual(isNever(1), false)
* assert.strictEqual(isNever(null), false)
* assert.strictEqual(isNever({}), false)
* ```
*
* @category guards
* @since 2.0.0
*/
export declare const isNever: (input: unknown) => input is never;
/**
* A refinement that always returns `true`. The type is narrowed to `unknown`.
*
* @example
* ```ts
* import * as assert from "node:assert"
* import { isUnknown } from "effect/Predicate"
*
* assert.strictEqual(isUnknown(1), true)
* assert.strictEqual(isUnknown(null), true)
* assert.strictEqual(isUnknown({}), true)
* ```
*
* @category guards
* @since 2.0.0
*/
export declare const isUnknown: (input: unknown) => input is unknown;
/**
* A refinement that checks if a value is an `object`. Note that in JavaScript,
* arrays and functions are also considered objects.
*
* @example
* ```ts
* import * as assert from "node:assert"
* import { isObject } from "effect/Predicate"
*
* assert.strictEqual(isObject({}), true)
* assert.strictEqual(isObject([]), true)
* assert.strictEqual(isObject(() => {}), true)
*
* assert.strictEqual(isObject(null), false)
* assert.strictEqual(isObject("hello"), false)
* ```
*
* @category guards
* @since 2.0.0
* @see isRecord to check for plain objects (excluding arrays and functions).
*/
export declare const isObject: (input: unknown) => input is object;
/**
* A refinement that checks if a value is an object-like value and has a specific property key.
*
* @example
* ```ts
* import * as assert from "node:assert"
* import { hasProperty } from "effect/Predicate"
*
* assert.strictEqual(hasProperty({ a: 1 }, "a"), true)
* assert.strictEqual(hasProperty({ a: 1 }, "b"), false)
*
* const value: unknown = { name: "Alice" };
* if (hasProperty(value, "name")) {
* // The type of `value` is narrowed to `{ name: unknown }`
* // and we can safely access `value.name`
* console.log(value.name)
* }
* ```
*
* @category guards
* @since 2.0.0
*/
export declare const hasProperty: {
/**
* A refinement that checks if a value is an object-like value and has a specific property key.
*
* @example
* ```ts
* import * as assert from "node:assert"
* import { hasProperty } from "effect/Predicate"
*
* assert.strictEqual(hasProperty({ a: 1 }, "a"), true)
* assert.strictEqual(hasProperty({ a: 1 }, "b"), false)
*
* const value: unknown = { name: "Alice" };
* if (hasProperty(value, "name")) {
* // The type of `value` is narrowed to `{ name: unknown }`
* // and we can safely access `value.name`
* console.log(value.name)
* }
* ```
*
* @category guards
* @since 2.0.0
*/
<P extends PropertyKey>(property: P): (self: unknown) => self is {
[K in P]: unknown;
};
/**
* A refinement that checks if a value is an object-like value and has a specific property key.
*
* @example
* ```ts
* import * as assert from "node:assert"
* import { hasProperty } from "effect/Predicate"
*
* assert.strictEqual(hasProperty({ a: 1 }, "a"), true)
* assert.strictEqual(hasProperty({ a: 1 }, "b"), false)
*
* const value: unknown = { name: "Alice" };
* if (hasProperty(value, "name")) {
* // The type of `value` is narrowed to `{ name: unknown }`
* // and we can safely access `value.name`
* console.log(value.name)
* }
* ```
*
* @category guards
* @since 2.0.0
*/
<P extends PropertyKey>(self: unknown, property: P): self is {
[K in P]: unknown;
};
};
/**
* A refinement that checks if a value is an object with a `_tag` property
* that matches the given tag. This is a powerful tool for working with
* discriminated union types.
*
* @example
* ```ts
* import * as assert from "node:assert"
* import { isTagged } from "effect/Predicate"
*
* type Shape = { _tag: "circle"; radius: number } | { _tag: "square"; side: number }
*
* const isCircle = isTagged("circle")
*
* const shape1: Shape = { _tag: "circle", radius: 10 }
* const shape2: Shape = { _tag: "square", side: 5 }
*
* assert.strictEqual(isCircle(shape1), true)
* assert.strictEqual(isCircle(shape2), false)
*
* if (isCircle(shape1)) {
* // shape1 is now narrowed to { _tag: "circle"; radius: number }
* assert.strictEqual(shape1.radius, 10)
* }
* ```
*
* @category guards
* @since 2.0.0
*/
export declare const isTagged: {
/**
* A refinement that checks if a value is an object with a `_tag` property
* that matches the given tag. This is a powerful tool for working with
* discriminated union types.
*
* @example
* ```ts
* import * as assert from "node:assert"
* import { isTagged } from "effect/Predicate"
*
* type Shape = { _tag: "circle"; radius: number } | { _tag: "square"; side: number }
*
* const isCircle = isTagged("circle")
*
* const shape1: Shape = { _tag: "circle", radius: 10 }
* const shape2: Shape = { _tag: "square", side: 5 }
*
* assert.strictEqual(isCircle(shape1), true)
* assert.strictEqual(isCircle(shape2), false)
*
* if (isCircle(shape1)) {
* // shape1 is now narrowed to { _tag: "circle"; radius: number }
* assert.strictEqual(shape1.radius, 10)
* }
* ```
*
* @category guards
* @since 2.0.0
*/
<K extends string>(tag: K): (self: unknown) => self is {
_tag: K;
};
/**
* A refinement that checks if a value is an object with a `_tag` property
* that matches the given tag. This is a powerful tool for working with
* discriminated union types.
*
* @example
* ```ts
* import * as assert from "node:assert"
* import { isTagged } from "effect/Predicate"
*
* type Shape = { _tag: "circle"; radius: number } | { _tag: "square"; side: number }
*
* const isCircle = isTagged("circle")
*
* const shape1: Shape = { _tag: "circle", radius: 10 }
* const shape2: Shape = { _tag: "square", side: 5 }
*
* assert.strictEqual(isCircle(shape1), true)
* assert.strictEqual(isCircle(shape2), false)
*
* if (isCircle(shape1)) {
* // shape1 is now narrowed to { _tag: "circle"; radius: number }
* assert.strictEqual(shape1.radius, 10)
* }
* ```
*
* @category guards
* @since 2.0.0
*/
<K extends string>(self: unknown, tag: K): self is {
_tag: K;
};
};
/**
* A refinement that checks if a value is either `null` or `undefined`.
*
* @example
* ```ts
* import * as assert from "node:assert"
* import { isNullable } from "effect/Predicate"
*
* assert.strictEqual(isNullable(null), true)
* assert.strictEqual(isNullable(undefined), true)
*
* assert.strictEqual(isNullable(0), false)
* assert.strictEqual(isNullable(""), false)
* ```
*
* @category guards
* @since 2.0.0
* @see isNotNullable
*/
export declare const isNullable: <A>(input: A) => input is Extract<A, null | undefined>;
/**
* A refinement that checks if a value is neither `null` nor `undefined`.
* The type is narrowed to `NonNullable<A>`.
*
* @example
* ```ts
* import * as assert from "node:assert"
* import { isNotNullable } from "effect/Predicate"
*
* assert.strictEqual(isNotNullable(0), true)
* assert.strictEqual(isNotNullable("hello"), true)
*
* assert.strictEqual(isNotNullable(null), false)
* assert.strictEqual(isNotNullable(undefined), false)
* ```
*
* @category guards
* @since 2.0.0
* @see isNullable
*/
export declare const isNotNullable: <A>(input: A) => input is NonNullable<A>;
/**
* A refinement that checks if a value is an instance of `Error`.
*
* @example
* ```ts
* import * as assert from "node:assert"
* import { isError } from "effect/Predicate"
*
* assert.strictEqual(isError(new Error("boom")), true)
* assert.strictEqual(isError(new TypeError("boom")), true)
*
* assert.strictEqual(isError({ message: "boom" }), false)
* assert.strictEqual(isError("boom"), false)
* ```
*
* @category guards
* @since 2.0.0
*/
export declare const isError: (input: unknown) => input is Error;
/**
* A refinement that checks if a value is a `Uint8Array`.
*
* @example
* ```ts
* import * as assert from "node:assert"
* import { isUint8Array } from "effect/Predicate"
*
* assert.strictEqual(isUint8Array(new Uint8Array()), true)
*
* assert.strictEqual(isUint8Array(new Uint16Array()), false)
* assert.strictEqual(isUint8Array([1, 2, 3]), false)
* ```
*
* @category guards
* @since 2.0.0
*/
export declare const isUint8Array: (input: unknown) => input is Uint8Array;
/**
* A refinement that checks if a value is a `Date` object.
*
* @example
* ```ts
* import * as assert from "node:assert"
* import { isDate } from "effect/Predicate"
*
* assert.strictEqual(isDate(new Date()), true)
*
* assert.strictEqual(isDate(Date.now()), false) // `Date.now()` returns a number
* assert.strictEqual(isDate("2023-01-01"), false)
* ```
*
* @category guards
* @since 2.0.0
*/
export declare const isDate: (input: unknown) => input is Date;
/**
* A refinement that checks if a value is an `Iterable`.
* Many built-in types are iterable, such as `Array`, `string`, `Map`, and `Set`.
*
* @example
* ```ts
* import * as assert from "node:assert"
* import { isIterable } from "effect/Predicate"
*
* assert.strictEqual(isIterable([]), true)
* assert.strictEqual(isIterable("hello"), true)
* assert.strictEqual(isIterable(new Set()), true)
*
* assert.strictEqual(isIterable({}), false)
* assert.strictEqual(isIterable(123), false)
* ```
*
* @category guards
* @since 2.0.0
*/
export declare const isIterable: (input: unknown) => input is Iterable<unknown>;
/**
* A refinement that checks if a value is a record (i.e., a plain object).
* This check returns `false` for arrays, `null`, and functions.
*
* @example
* ```ts
* import * as assert from "node:assert"
* import { isRecord } from "effect/Predicate"
*
* assert.strictEqual(isRecord({}), true)
* assert.strictEqual(isRecord({ a: 1 }), true)
*
* assert.strictEqual(isRecord([]), false)
* assert.strictEqual(isRecord(new Date()), false)
* assert.strictEqual(isRecord(null), false)
* assert.strictEqual(isRecord(() => null), false)
* ```
*
* @category guards
* @since 2.0.0
* @see isObject
*/
export declare const isRecord: (input: unknown) => input is {
[x: string | symbol]: unknown;
};
/**
* A refinement that checks if a value is a readonly record (i.e., a plain object).
* This check returns `false` for arrays, `null`, and functions.
*
* This is an alias for `isRecord`.
*
* @example
* ```ts
* import * as assert from "node:assert"
* import { isReadonlyRecord } from "effect/Predicate"
*
* assert.strictEqual(isReadonlyRecord({}), true)
* assert.strictEqual(isReadonlyRecord({ a: 1 }), true)
*
* assert.strictEqual(isReadonlyRecord([]), false)
* assert.strictEqual(isReadonlyRecord(null), false)
* ```
*
* @category guards
* @since 2.0.0
*/
export declare const isReadonlyRecord: (input: unknown) => input is {
readonly [x: string | symbol]: unknown;
};
/**
* A refinement that checks if a value is a `Promise`. It performs a duck-typing check
* for `.then` and `.catch` methods.
*
* @example
* ```ts
* import * as assert from "node:assert"
* import { isPromise } from "effect/Predicate"
*
* assert.strictEqual(isPromise(Promise.resolve(1)), true)
* assert.strictEqual(isPromise(new Promise(() => {})), true)
*
* assert.strictEqual(isPromise({ then() {} }), false) // Missing .catch
* assert.strictEqual(isPromise({}), false)
* ```
*
* @category guards
* @since 2.0.0
* @see isPromiseLike
*/
export declare const isPromise: (input: unknown) => input is Promise<unknown>;
/**
* A refinement that checks if a value is `PromiseLike`. It performs a duck-typing
* check for a `.then` method.
*
* @example
* ```ts
* import * as assert from "node:assert"
* import { isPromiseLike } from "effect/Predicate"
*
* assert.strictEqual(isPromiseLike(Promise.resolve(1)), true)
* assert.strictEqual(isPromiseLike({ then: () => {} }), true)
*
* assert.strictEqual(isPromiseLike({}), false)
* ```
*
* @category guards
* @since 2.0.0
* @see isPromise
*/
export declare const isPromiseLike: (input: unknown) => input is PromiseLike<unknown>;
/**
* A refinement that checks if a value is a `RegExp`.
*
* @example
* ```ts
* import * as assert from "node:assert"
* import { Predicate } from "effect"
*
* assert.strictEqual(Predicate.isRegExp(/a/), true)
* assert.strictEqual(Predicate.isRegExp(new RegExp("a")), true)
*
* assert.strictEqual(Predicate.isRegExp("/a/"), false)
* ```
*
* @category guards
* @since 3.9.0
*/
export declare const isRegExp: (input: unknown) => input is RegExp;
/**
* Composes a `Refinement` with another `Refinement` or `Predicate`.
*
* This can be used to chain checks. The first refinement is applied, and if it
* passes, the second check is applied to the same value, potentially refining
* the type further.
*
* @example
* ```ts
* import { Predicate } from "effect"
* import * as assert from "node:assert"
*
* const isString = (u: unknown): u is string => typeof u === "string"
* const minLength = (n: number) => (s: string): boolean => s.length >= n
*
* // Create a refinement that checks for a string with a minimum length of 3
* const isLongString = Predicate.compose(isString, minLength(3))
*
* let value: unknown = "hello"
*
* assert.strictEqual(isLongString(value), true)
* if (isLongString(value)) {
* // value is narrowed to string
* assert.strictEqual(value.toUpperCase(), "HELLO")
* }
* assert.strictEqual(isLongString("hi"), false)
* ```
*
* @since 2.0.0
*/
export declare const compose: {
/**
* Composes a `Refinement` with another `Refinement` or `Predicate`.
*
* This can be used to chain checks. The first refinement is applied, and if it
* passes, the second check is applied to the same value, potentially refining
* the type further.
*
* @example
* ```ts
* import { Predicate } from "effect"
* import * as assert from "node:assert"
*
* const isString = (u: unknown): u is string => typeof u === "string"
* const minLength = (n: number) => (s: string): boolean => s.length >= n
*
* // Create a refinement that checks for a string with a minimum length of 3
* const isLongString = Predicate.compose(isString, minLength(3))
*
* let value: unknown = "hello"
*
* assert.strictEqual(isLongString(value), true)
* if (isLongString(value)) {
* // value is narrowed to string
* assert.strictEqual(value.toUpperCase(), "HELLO")
* }
* assert.strictEqual(isLongString("hi"), false)
* ```
*
* @since 2.0.0
*/
<A, B extends A, C extends B, D extends C>(bc: Refinement<C, D>): (ab: Refinement<A, B>) => Refinement<A, D>;
/**
* Composes a `Refinement` with another `Refinement` or `Predicate`.
*
* This can be used to chain checks. The first refinement is applied, and if it
* passes, the second check is applied to the same value, potentially refining
* the type further.
*
* @example
* ```ts
* import { Predicate } from "effect"
* import * as assert from "node:assert"
*
* const isString = (u: unknown): u is string => typeof u === "string"
* const minLength = (n: number) => (s: string): boolean => s.length >= n
*
* // Create a refinement that checks for a string with a minimum length of 3
* const isLongString = Predicate.compose(isString, minLength(3))
*
* let value: unknown = "hello"
*
* assert.strictEqual(isLongString(value), true)
* if (isLongString(value)) {
* // value is narrowed to string
* assert.strictEqual(value.toUpperCase(), "HELLO")
* }
* assert.strictEqual(isLongString("hi"), false)
* ```
*
* @since 2.0.0
*/
<A, B extends A>(bc: Predicate<NoInfer<B>>): (ab: Refinement<A, B>) => Refinement<A, B>;
/**
* Composes a `Refinement` with another `Refinement` or `Predicate`.
*
* This can be used to chain checks. The first refinement is applied, and if it
* passes, the second check is applied to the same value, potentially refining
* the type further.
*
* @example
* ```ts
* import { Predicate } from "effect"
* import * as assert from "node:assert"
*
* const isString = (u: unknown): u is string => typeof u === "string"
* const minLength = (n: number) => (s: string): boolean => s.length >= n
*
* // Create a refinement that checks for a string with a minimum length of 3
* const isLongString = Predicate.compose(isString, minLength(3))
*
* let value: unknown = "hello"
*
* assert.strictEqual(isLongString(value), true)
* if (isLongString(value)) {
* // value is narrowed to string
* assert.strictEqual(value.toUpperCase(), "HELLO")
* }
* assert.strictEqual(isLongString("hi"), false)
* ```
*
* @since 2.0.0
*/
<A, B extends A, C extends B, D extends C>(ab: Refinement<A, B>, bc: Refinement<C, D>): Refinement<A, D>;
/**
* Composes a `Refinement` with another `Refinement` or `Predicate`.
*
* This can be used to chain checks. The first refinement is applied, and if it
* passes, the second check is applied to the same value, potentially refining
* the type further.
*
* @example
* ```ts
* import { Predicate } from "effect"
* import * as assert from "node:assert"
*
* const isString = (u: unknown): u is string => typeof u === "string"
* const minLength = (n: number) => (s: string): boolean => s.length >= n
*
* // Create a refinement that checks for a string with a minimum length of 3
* const isLongString = Predicate.compose(isString, minLength(3))
*
* let value: unknown = "hello"
*
* assert.strictEqual(isLongString(value), true)
* if (isLongString(value)) {
* // value is narrowed to string
* assert.strictEqual(value.toUpperCase(), "HELLO")
* }
* assert.strictEqual(isLongString("hi"), false)
* ```
*
* @since 2.0.0
*/
<A, B extends A>(ab: Refinement<A, B>, bc: Predicate<NoInfer<B>>): Refinement<A, B>;
};
/**
* Combines two predicates to test a tuple of two values. The first predicate tests the
* first element of the tuple, and the second predicate tests the second element.
*
* @category combining
* @since 2.0.0
*/
export declare const product: <A, B>(self: Predicate<A>, that: Predicate<B>) => Predicate<readonly [A, B]>;
/**
* Takes an iterable of predicates and returns a new predicate that tests an array of values.
* The new predicate returns `true` if each predicate at a given index is satisfied by the
* value at the same index in the array. The check stops at the length of the shorter of
* the two iterables (predicates or values).
*
* @category combining
* @since 2.0.0
* @see tuple for a more powerful, variadic version.
*/
export declare const all: <A>(collection: Iterable<Predicate<A>>) => Predicate<ReadonlyArray<A>>;
/**
* Combines a predicate for a single value and an iterable of predicates for the rest of an array.
* Useful for checking the head and tail of an array separately.
*
* @category combining
* @since 2.0.0
*/
export declare const productMany: <A>(self: Predicate<A>, collection: Iterable<Predicate<A>>) => Predicate<readonly [A, ...Array<A>]>;
/**
* Combines an array of predicates into a single predicate that tests an array of values.
* This function is highly type-aware and will produce a `Refinement` if any of the provided
* predicates are `Refinement`s, allowing for powerful type-narrowing of tuples.
*
* - If all predicates are `Predicate<T>`, the result is `Predicate<[T, T, ...]>`.
* - If any predicate is a `Refinement<A, B>`, the result is a `Refinement` that narrows
* the input tuple type to a more specific tuple type.
*
* @example
* ```ts
* import * as assert from "node:assert"
* import { Predicate } from "effect"
*
* const isString = (u: unknown): u is string => typeof u === "string"
* const isNumber = (u: unknown): u is number => typeof u === "number"
*
* // Create a refinement for a [string, number] tuple
* const isStringNumberTuple = Predicate.tuple(isString, isNumber)
*
* const value: [unknown, unknown] = ["hello", 123]
* if (isStringNumberTuple(value)) {
* // value is narrowed to [string, number]
* const [s, n] = value
* assert.strictEqual(s.toUpperCase(), "HELLO")
* assert.strictEqual(n.toFixed(2), "123.00")
* }
* assert.strictEqual(isStringNumberTuple(["hello", "123"]), false)
* ```
*
* @since 2.0.0
*/
export declare const tuple: {
/**
* Combines an array of predicates into a single predicate that tests an array of values.
* This function is highly type-aware and will produce a `Refinement` if any of the provided
* predicates are `Refinement`s, allowing for powerful type-narrowing of tuples.
*
* - If all predicates are `Predicate<T>`, the result is `Predicate<[T, T, ...]>`.
* - If any predicate is a `Refinement<A, B>`, the result is a `Refinement` that narrows
* the input tuple type to a more specific tuple type.
*
* @example
* ```ts
* import * as assert from "node:assert"
* import { Predicate } from "effect"
*
* const isString = (u: unknown): u is string => typeof u === "string"
* const isNumber = (u: unknown): u is number => typeof u === "number"
*
* // Create a refinement for a [string, number] tuple
* const isStringNumberTuple = Predicate.tuple(isString, isNumber)
*
* const value: [unknown, unknown] = ["hello", 123]
* if (isStringNumberTuple(value)) {
* // value is narrowed to [string, number]
* const [s, n] = value
* assert.strictEqual(s.toUpperCase(), "HELLO")
* assert.strictEqual(n.toFixed(2), "123.00")
* }
* assert.strictEqual(isStringNumberTuple(["hello", "123"]), false)
* ```
*
* @since 2.0.0
*/
<T extends ReadonlyArray<Predicate.Any>>(...elements: T): [Extract<T[number], Refinement.Any>] extends [never] ? Predicate<{
readonly [I in keyof T]: Predicate.In<T[I]>;
}> : Refinement<{
readonly [I in keyof T]: T[I] extends Refinement.Any ? Refinement.In<T[I]> : Predicate.In<T[I]>;
}, {
readonly [I in keyof T]: T[I] extends Refinement.Any ? Refinement.Out<T[I]> : Predicate.In<T[I]>;
}>;
};
/**
* Combines a record of predicates into a single predicate that tests a record of values.
* This function is highly type-aware and will produce a `Refinement` if any of the provided
* predicates are `Refinement`s, allowing for powerful type-narrowing of structs.
*
* - If all predicates are `Predicate<T>`, the result is `Predicate<{ k: T, ... }>`.
* - If any predicate is a `Refinement<A, B>`, the result is a `Refinement` that narrows
* the input record type to a more specific record type.
*
* @example
* ```ts
* import * as assert from "node:assert"
* import { Predicate } from "effect"
*
* const isString = (u: unknown): u is string => typeof u === "string"
* const isNumber = (u: unknown): u is number => typeof u === "number"
*
* const personPredicate = Predicate.struct({
* name: isString,
* age: isNumber
* })
*
* const value: { name: unknown; age: unknown } = { name: "Alice", age: 30 }
* if (personPredicate(value)) {
* // value is narrowed to { name: string; age: number }
* assert.strictEqual(value.name.toUpperCase(), "ALICE")
* assert.strictEqual(value.age.toFixed(0), "30")
* }
* assert.strictEqual(personPredicate({ name: "Bob", age: "40" }), false)
* ```
*
* @since 2.0.0
*/
export declare const struct: {
/**
* Combines a record of predicates into a single predicate that tests a record of values.
* This function is highly type-aware and will produce a `Refinement` if any of the provided
* predicates are `Refinement`s, allowing for powerful type-narrowing of structs.
*
* - If all predicates are `Predicate<T>`, the result is `Predicate<{ k: T, ... }>`.
* - If any predicate is a `Refinement<A, B>`, the result is a `Refinement` that narrows
* the input record type to a more specific record type.
*
* @example
* ```ts
* import * as assert from "node:assert"
* import { Predicate } from "effect"
*
* const isString = (u: unknown): u is string => typeof u === "string"
* const isNumber = (u: unknown): u is number => typeof u === "number"
*
* const personPredicate = Predicate.struct({
* name: isString,
* age: isNumber
* })
*
* const value: { name: unknown; age: unknown } = { name: "Alice", age: 30 }
* if (personPredicate(value)) {
* // value is narrowed to { name: string; age: number }
* assert.strictEqual(value.name.toUpperCase(), "ALICE")
* assert.strictEqual(value.age.toFixed(0), "30")
* }
* assert.strictEqual(personPredicate({ name: "Bob", age: "40" }), false)
* ```
*
* @since 2.0.0
*/
<R extends Record<string, Predicate.Any>>(fields: R): [Extract<R[keyof R], Refinement.Any>] extends [never] ? Predicate<{
readonly [K in keyof R]: Predicate.In<R[K]>;
}> : Refinement<{
readonly [K in keyof R]: R[K] extends Refinement.Any ? Refinement.In<R[K]> : Predicate.In<R[K]>;
}, {
readonly [K in keyof R]: R[K] extends Refinement.Any ? Refinement.Out<R[K]> : Predicate.In<R[K]>;
}>;
};
/**
* Returns a new predicate that is the logical negation of the given predicate.
*
* **Note**: If the input is a `Refinement`, the resulting predicate will be a
* simple `Predicate`, as TypeScript cannot infer the negative type.
*
* @example
* ```ts
* import * as assert from "node:assert"
* import { Predicate, Number } from "effect"
*
* const isNonPositive = Predicate.not(Number.greaterThan(0))
*
* assert.strictEqual(isNonPositive(-1), true)
* assert.strictEqual(isNonPositive(0), true)
* assert.strictEqual(isNonPositive(1), false)
* ```
*
* @category combinators
* @since 2.0.0
*/
export declare const not: <A>(self: Predicate<A>) => Predicate<A>;
/**
* Combines two predicates with a logical "OR". The resulting predicate returns `true`
* if at least one of the predicates returns `true`.
*
* If both predicates are `Refinement`s, the resulting predicate is a `Refinement` to the
* union of their target types (`B | C`).
*
* @example
* ```ts
* import * as assert from "node:assert"
* import { Predicate } from "effect"
*
* const isString = (u: unknown): u is string => typeof u === "string"
* const isNumber = (u: unknown): u is number => typeof u === "number"
*
* const isStringOrNumber = Predicate.or(isString, isNumber)
*
* assert.strictEqual(isStringOrNumber("hello"), true)
* assert.strictEqual(isStringOrNumber(123), true)
* assert.strictEqual(isStringOrNumber(null), false)
*
* const value: unknown = "world"
* if (isStringOrNumber(value)) {
* // value is narrowed to string | number
* console.log(value)
* }
* ```
*
* @category combinators
* @since 2.0.0
*/
export declare const or: {
/**
* Combines two predicates with a logical "OR". The resulting predicate returns `true`
* if at least one of the predicates returns `true`.
*
* If both predicates are `Refinement`s, the resulting predicate is a `Refinement` to the
* union of their target types (`B | C`).
*
* @example
* ```ts
* import * as assert from "node:assert"
* import { Predicate } from "effect"
*
* const isString = (u: unknown): u is string => typeof u === "string"
* const isNumber = (u: unknown): u is number => typeof u === "number"
*
* const isStringOrNumber = Predicate.or(isString, isNumber)
*
* assert.strictEqual(isStringOrNumber("hello"), true)
* assert.strictEqual(isStringOrNumber(123), true)
* assert.strictEqual(isStringOrNumber(null), false)
*
* const value: unknown = "world"
* if (isStringOrNumber(value)) {
* // value is narrowed to string | number
* console.log(value)
* }
* ```
*
* @category combinators
* @since 2.0.0
*/
<A, C extends A>(that: Refinement<A, C>): <B extends A>(self: Refinement<A, B>) => Refinement<A, B | C>;
/**
* Combines two predicates with a logical "OR". The resulting predicate returns `true`
* if at least one of the predicates returns `true`.
*
* If both predicates are `Refinement`s, the resulting predicate is a `Refinement` to the
* union of their target types (`B | C`).
*
* @example
* ```ts
* import * as assert from "node:assert"
* import { Predicate } from "effect"
*
* const isString = (u: unknown): u is string => typeof u === "string"
* const isNumber = (u: unknown): u is number => typeof u === "number"
*
* const isStringOrNumber = Predicate.or(isString, isNumber)
*
* assert.strictEqual(isStringOrNumber("hello"), true)
* assert.strictEqual(isStringOrNumber(123), true)
* assert.strictEqual(isStringOrNumber(null), false)
*
* const value: unknown = "world"
* if (isStringOrNumber(value)) {
* // value is narrowed to string | number
* console.log(value)
* }
* ```
*
* @category combinators
* @since 2.0.0
*/
<A, B extends A, C extends A>(self: Refinement<A, B>, that: Refinement<A, C>): Refinement<A, B | C>;
/**
* Combines two predicates with a logical "OR". The resulting predicate returns `true`
* if at least one of the predicates returns `true`.
*
* If both predicates are `Refinement`s, the resulting predicate is a `Refinement` to the
* union of their target types (`B | C`).
*
* @example
* ```ts
* import * as assert from "node:assert"
* import { Predicate } from "effect"
*
* const isString = (u: unknown): u is string => typeof u === "string"
* const isNumber = (u: unknown): u is number => typeof u === "number"
*
* const isStringOrNumber = Predicate.or(isString, isNumber)
*
* assert.strictEqual(isStringOrNumber("hello"), true)
* assert.strictEqual(isStringOrNumber(123), true)
* assert.strictEqual(isStringOrNumber(null), false)
*
* const value: unknown = "world"
* if (isStringOrNumber(value)) {
* // value is narrowed to string | number
* console.log(value)
* }
* ```
*
* @category combinators
* @since 2.0.0
*/
<A>(that: Predicate<A>): (self: Predicate<A>) => Predicate<A>;
/**
* Combines two predicates with a logical "OR". The resulting predicate returns `true`
* if at least one of the predicates returns `true`.
*
* If both predicates are `Refinement`s, the resulting predicate is a `Refinement` to the
* union of their target types (`B | C`).
*
* @example
* ```ts
* import * as assert from "node:assert"
* import { Predicate } from "effect"
*
* const isString = (u: unknown): u is string => typeof u === "string"
* const isNumber = (u: unknown): u is number => typeof u === "number"
*
* const isStringOrNumber = Predicate.or(isString, isNumber)
*
* assert.strictEqual(isStringOrNumber("hello"), true)
* assert.strictEqual(isStringOrNumber(123), true)
* assert.strictEqual(isStringOrNumber(null), false)
*
* const value: unknown = "world"
* if (isStringOrNumber(value)) {
* // value is narrowed to string | number
* console.log(value)
* }
* ```
*
* @category combinators
* @since 2.0.0
*/
<A>(self: Predicate<A>, that: Predicate<A>): Predicate<A>;
};
/**
* Combines two predicates with a logical "AND". The resulting predicate returns `true`
* only if both of the predicates return `true`.
*
* If both predicates are `Refinement`s, the resulting predicate is a `Refinement` to the
* intersection of their target types (`B & C`).
*
* @example
* ```ts
* import * as assert from "node:assert"
* import { Predicate } from "effect"
*
* type Person = { name: string }
* type Employee = { id: number }
*
* const hasName = (u: unknown): u is Person => Predicate.hasProperty(u, "name") && typeof (u as any).name === "string"
* const hasId = (u: unknown): u is Employee => Predicate.hasProperty(u, "id") && typeof (u as any).id === "number"
*
* const isPersonAndEmployee = Predicate.and(hasName, hasId)
*
* const val: unknown = { name: "Alice", id: 123 }
* if (isPersonAndEmployee(val)) {
* // val is narrowed to Person & Employee
* assert.strictEqual(val.name, "Alice")
* assert.strictEqual(val.id, 123)
* }
*
* assert.strictEqual(isPersonAndEmployee({ name: "Bob" }), false) // Missing id
* assert.strictEqual(isPersonAndEmployee({ id: 456 }), false) // Missing name
* ```
*
* @category combinators
* @since 2.0.0
*/
export declare const and: {
/**
* Combines two predicates with a logical "AND". The resulting predicate returns `true`
* only if both of the predicates return `true`.
*
* If both predicates are `Refinement`s, the resulting predicate is a `Refinement` to the
* intersection of their target types (`B & C`).
*
* @example
* ```ts
* import * as assert from "node:assert"
* import { Predicate } from "effect"
*
* type Person = { name: string }
* type Employee = { id: number }
*
* const hasName = (u: unknown): u is Person => Predicate.hasProperty(u, "name") && typeof (u as any).name === "string"
* const hasId = (u: unknown): u is Employee => Predicate.hasProperty(u, "id") && typeof (u as any).id === "number"
*
* const isPersonAndEmployee = Predicate.and(hasName, hasId)
*
* const val: unknown = { name: "Alice", id: 123 }
* if (isPersonAndEmployee(val)) {
* // val is narrowed to Person & Employee
* assert.strictEqual(val.name, "Alice")
* assert.strictEqual(val.id, 123)
* }
*
* assert.strictEqual(isPersonAndEmployee({ name: "Bob" }), false) // Missing id
* assert.strictEqual(isPersonAndEmployee({ id: 456 }), false) // Missing name
* ```
*
* @category combinators
* @since 2.0.0
*/
<A, C extends A>(that: Refinement<A, C>): <B extends A>(self: Refinement<A, B>) => Refinement<A, B & C>;
/**
* Combines two predicates with a logical "AND". The resulting predicate returns `true`
* only if both of the predicates return `true`.
*
* If both predicates are `Refinement`s, the resulting predicate is a `Refinement` to the
* intersection of their target types (`B & C`).
*
* @example
* ```ts
* import * as assert from "node:assert"
* import { Predicate } from "effect"
*
* type Person = { name: string }
* type Employee = { id: number }
*
* const hasName = (u: unknown): u is Person => Predicate.hasProperty(u, "name") && typeof (u as any).name === "string"
* const hasId = (u: unknown): u is Employee => Predicate.hasProperty(u, "id") && typeof (u as any).id === "number"
*
* const isPersonAndEmployee = Predicate.and(hasName, hasId)
*
* const val: unknown = { name: "Alice", id: 123 }
* if (isPersonAndEmployee(val)) {
* // val is narrowed to Person & Employee
* assert.strictEqual(val.name, "Alice")
* assert.strictEqual(val.id, 123)
* }
*
* assert.strictEqual(isPersonAndEmployee({ name: "Bob" }), false) // Missing id
* assert.strictEqual(isPersonAndEmployee({ id: 456 }), false) // Missing name
* ```
*
* @category combinators
* @since 2.0.0
*/
<A, B extends A, C extends A>(self: Refinement<A, B>, that: Refinement<A, C>): Refinement<A, B & C>;
/**
* Combines two predicates with a logical "AND". The resulting predicate returns `true`
* only if both of the predicates return `true`.
*
* If both predicates are `Refinement`s, the resulting predicate is a `Refinement` to the
* intersection of their target types (`B & C`).
*
* @example
* ```ts
* import * as assert from "node:assert"
* import { Predicate } from "effect"
*
* type Person = { name: string }
* type Employee = { id: number }
*
* const hasName = (u: unknown): u is Person => Predicate.hasProperty(u, "name") && typeof (u as any).name === "string"
* const hasId = (u: unknown): u is Employee => Predicate.hasProperty(u, "id") && typeof (u as any).id === "number"
*
* const isPersonAndEmployee = Predicate.and(hasName, hasId)
*
* const val: unknown = { name: "Alice", id: 123 }
* if (isPersonAndEmployee(val)) {
* // val is narrowed to Person & Employee
* assert.strictEqual(val.name, "Alice")
* assert.strictEqual(val.id, 123)
* }
*
* assert.strictEqual(isPersonAndEmployee({ name: "Bob" }), false) // Missing id
* assert.strictEqual(isPersonAndEmployee({ id: 456 }), false) // Missing name
* ```
*
* @category combinators
* @since 2.0.0
*/
<A>(that: Predicate<A>): (self: Predicate<A>) => Predicate<A>;
/**
* Combines two predicates with a logical "AND". The resulting predicate returns `true`
* only if both of the predicates return `true`.
*
* If both predicates are `Refinement`s, the resulting predicate is a `Refinement` to the
* intersection of their target types (`B & C`).
*
* @example
* ```ts
* import * as assert from "node:assert"
* import { Predicate } from "effect"
*
* type Person = { name: string }
* type Employee = { id: number }
*
* const hasName = (u: unknown): u is Person => Predicate.hasProperty(u, "name") && typeof (u as any).name === "string"
* const hasId = (u: unknown): u is Employee => Predicate.hasProperty(u, "id") && typeof (u as any).id === "number"
*
* const isPersonAndEmployee = Predicate.and(hasName, hasId)
*
* const val: unknown = { name: "Alice", id: 123 }
* if (isPersonAndEmployee(val)) {
* // val is narrowed to Person & Employee
* assert.strictEqual(val.name, "Alice")
* assert.strictEqual(val.id, 123)
* }
*
* assert.strictEqual(isPersonAndEmployee({ name: "Bob" }), false) // Missing id
* assert.strictEqual(isPersonAndEmployee({ id: 456 }), false) // Missing name
* ```
*
* @category combinators
* @since 2.0.0
*/
<A>(self: Predicate<A>, that: Predicate<A>): Predicate<A>;
};
/**
* Combines two predicates with a logical "XOR" (exclusive OR). The resulting predicate
* returns `true` if one of the predicates returns `true`, but not both.
*
* @example
* ```ts
* import * as assert from "node:assert"
* import { Predicate } from "effect"
*
* const isPositive = (n: number) => n > 0
* const isEven = (n: number) => n % 2 === 0
*
* const isPositiveXorEven = Predicate.xor(isPositive, isEven)
*
* assert.strictEqual(isPositiveXorEven(4), false) // both true -> false
* assert.strictEqual(isPositiveXorEven(3), true) // one true -> true
* assert.strictEqual(isPositiveXorEven(-2), true) // one true -> true
* assert.strictEqual(isPositiveXorEven(-1), false) // both false -> false
* ```
*
* @category combinators
* @since 2.0.0
*/
export declare const xor: {
/**
* Combines two predicates with a logical "XOR" (exclusive OR). The resulting predicate
* returns `true` if one of the predicates returns `true`, but not both.
*
* @example
* ```ts
* import * as assert from "node:assert"
* import { Predicate } from "effect"
*
* const isPositive = (n: number) => n > 0
* const isEven = (n: number) => n % 2 === 0
*
* const isPositiveXorEven = Predicate.xor(isPositive, isEven)
*
* assert.strictEqual(isPositiveXorEven(4), false) // both true -> false
* assert.strictEqual(isPositiveXorEven(3), true) // one true -> true
* assert.strictEqual(isPositiveXorEven(-2), true) // one true -> true
* assert.strictEqual(isPositiveXorEven(-1), false) // both false -> false
* ```
*
* @category combinators
* @since 2.0.0
*/
<A>(that: Predicate<A>): (self: Predicate<A>) => Predicate<A>;
/**
* Combines two predicates with a logical "XOR" (exclusive OR). The resulting predicate
* returns `true` if one of the predicates returns `true`, but not both.
*
* @example
* ```ts
* import * as assert from "node:assert"
* import { Predicate } from "effect"
*
* const isPositive = (n: number) => n > 0
* const isEven = (n: number) => n % 2 === 0
*
* const isPositiveXorEven = Predicate.xor(isPositive, isEven)
*
* assert.strictEqual(isPositiveXorEven(4), false) // both true -> false
* assert.strictEqual(isPositiveXorEven(3), true) // one true -> true
* assert.strictEqual(isPositiveXorEven(-2), true) // one true -> true
* assert.strictEqual(isPositiveXorEven(-1), false) // both false -> false
* ```
*
* @category combinators
* @since 2.0.0
*/
<A>(self: Predicate<A>, that: Predicate<A>): Predicate<A>;
};
/**
* Combines two predicates with a logical "EQV" (equivalence). The resulting predicate
* returns `true` if both predicates return the same boolean value (both `true` or both `false`).
*
* @example
* ```ts
* import * as assert from "node:assert"
* import { Predicate } from "effect"
*
* const isPositive = (n: number) => n > 0
* const isEven = (n: number) => n % 2 === 0
*
* const isPositiveEqvEven = Predicate.eqv(isPositive, isEven)
*
* assert.strictEqual(isPositiveEqvEven(4), true) // both true -> true
* assert.strictEqual(isPositiveEqvEven(3), false) // different -> false
* assert.strictEqual(isPositiveEqvEven(-2), false) // different -> false
* assert.strictEqual(isPositiveEqvEven(-1), true) // both false -> true
* ```
*
* @category combinators
* @since 2.0.0
*/
export declare const eqv: {
/**
* Combines two predicates with a logical "EQV" (equivalence). The resulting predicate
* returns `true` if both predicates return the same boolean value (both `true` or both `false`).
*
* @example
* ```ts
* import * as assert from "node:assert"
* import { Predicate } from "effect"
*
* const isPositive = (n: number) => n > 0
* const isEven = (n: number) => n % 2 === 0
*
* const isPositiveEqvEven = Predicate.eqv(isPositive, isEven)
*
* assert.strictEqual(isPositiveEqvEven(4), true) // both true -> true
* assert.strictEqual(isPositiveEqvEven(3), false) // different -> false
* assert.strictEqual(isPositiveEqvEven(-2), false) // different -> false
* assert.strictEqual(isPositiveEqvEven(-1), true) // both false -> true
* ```
*
* @category combinators
* @since 2.0.0
*/
<A>(that: Predicate<A>): (self: Predicate<A>) => Predicate<A>;
/**
* Combines two predicates with a logical "EQV" (equivalence). The resulting predicate
* returns `true` if both predicates return the same boolean value (both `true` or both `false`).
*
* @example
* ```ts
* import * as assert from "node:assert"
* import { Predicate } from "effect"
*
* const isPositive = (n: number) => n > 0
* const isEven = (n: number) => n % 2 === 0
*
* const isPositiveEqvEven = Predicate.eqv(isPositive, isEven)
*
* assert.strictEqual(isPositiveEqvEven(4), true) // both true -> true
* assert.strictEqual(isPositiveEqvEven(3), false) // different -> false
* assert.strictEqual(isPositiveEqvEven(-2), false) // different -> false
* assert.strictEqual(isPositiveEqvEven(-1), true) // both false -> true
* ```
*
* @category combinators
* @since 2.0.0
*/
<A>(self: Predicate<A>, that: Predicate<A>): Predicate<A>;
};
/**
* Creates a predicate that represents a logical "if-then" rule.
*
* Think of it as a conditional promise: **"If `antecedent` holds true, then I promise `consequent` will also be true."**
*
* This function is invaluable for defining complex validation logic where one condition dictates another.
*
* ### How It Works
*
* The rule only fails (returns `false`) when the "if" part is `true`, but the "then" part is `false`.
* In all other cases, the promise is considered kept, and the result is `true`.
*
* This includes the concept of **"vacuous truth"**: if the "if" part is `false`, the rule doesn't apply,
* so the promise isn't broken, and the result is `true`. (e.g., "If it rains, I'll bring an umbrella."
* If it doesn't rain, you haven't broken your promise, no matter what).
*
* ### Key Details
*
* - **Logical Equivalence**: `implies(p, q)` is the same as `not(p).or(q)`, or simply `!p || q`
* in plain JavaScript. This can be a helpful way to reason about its behavior.
*
* - **Type-Safety Warning**: This function always returns a `Predicate`, never a type-narrowing
* `Refinement`. A `true` result doesn't guarantee the `consequent` passed (it could be `true`
* simply because the `antecedent` was `false`), so it cannot be used to safely narrow a type.
*
* @example
* ```ts
* // Rule: A user can only be an admin if they also belong to the "staff" group.
* import * as assert from "node:assert"
* import { Predicate } from "effect"
*
* type User = {
* isStaff: boolean
* isAdmin: boolean
* }
*
* const isValidUserPermission = Predicate.implies(
* // antecedent: "if" the user is an admin...
* (user: User) => user.isAdmin,
* // consequent: "then" they must be staff.
* (user: User) => user.isStaff
* )
*
* // A non-admin who is not staff. Rule doesn't apply (antecedent is false).
* assert.strictEqual(isValidUserPermission({ isStaff: false, isAdmin: false }), true)
*
* // A staff member who is not an admin. Rule doesn't apply (antecedent is false).
* assert.strictEqual(isValidUserPermission({ isStaff: true, isAdmin: false }), true)
*
* // An admin who is also staff. The rule was followed.
* assert.strictEqual(isValidUserPermission({ isStaff: true, isAdmin: true }), true)
*
* // An admin who is NOT staff. The rule was broken!
* assert.strictEqual(isValidUserPermission({ isStaff: false, isAdmin: true }), false)
* ```
*
* @category combinators
* @since 2.0.0
*/
export declare const implies: {
/**
* Creates a predicate that represents a logical "if-then" rule.
*
* Think of it as a conditional promise: **"If `antecedent` holds true, then I promise `consequent` will also be true."**
*
* This function is invaluable for defining complex validation logic where one condition dictates another.
*
* ### How It Works
*
* The rule only fails (returns `false`) when the "if" part is `true`, but the "then" part is `false`.
* In all other cases, the promise is considered kept, and the result is `true`.
*
* This includes the concept of **"vacuous truth"**: if the "if" part is `false`, the rule doesn't apply,
* so the promise isn't broken, and the result is `true`. (e.g., "If it rains, I'll bring an umbrella."
* If it doesn't rain, you haven't broken your promise, no matter what).
*
* ### Key Details
*
* - **Logical Equivalence**: `implies(p, q)` is the same as `not(p).or(q)`, or simply `!p || q`
* in plain JavaScript. This can be a helpful way to reason about its behavior.
*
* - **Type-Safety Warning**: This function always returns a `Predicate`, never a type-narrowing
* `Refinement`. A `true` result doesn't guarantee the `consequent` passed (it could be `true`
* simply because the `antecedent` was `false`), so it cannot be used to safely narrow a type.
*
* @example
* ```ts
* // Rule: A user can only be an admin if they also belong to the "staff" group.
* import * as assert from "node:assert"
* import { Predicate } from "effect"
*
* type User = {
* isStaff: boolean
* isAdmin: boolean
* }
*
* const isValidUserPermission = Predicate.implies(
* // antecedent: "if" the user is an admin...
* (user: User) => user.isAdmin,
* // consequent: "then" they must be staff.
* (user: User) => user.isStaff
* )
*
* // A non-admin who is not staff. Rule doesn't apply (antecedent is false).
* assert.strictEqual(isValidUserPermission({ isStaff: false, isAdmin: false }), true)
*
* // A staff member who is not an admin. Rule doesn't apply (antecedent is false).
* assert.strictEqual(isValidUserPermission({ isStaff: true, isAdmin: false }), true)
*
* // An admin who is also staff. The rule was followed.
* assert.strictEqual(isValidUserPermission({ isStaff: true, isAdmin: true }), true)
*
* // An admin who is NOT staff. The rule was broken!
* assert.strictEqual(isValidUserPermission({ isStaff: false, isAdmin: true }), false)
* ```
*
* @category combinators
* @since 2.0.0
*/
<A>(consequent: Predicate<A>): (antecedent: Predicate<A>) => Predicate<A>;
/**
* Creates a predicate that represents a logical "if-then" rule.
*
* Think of it as a conditional promise: **"If `antecedent` holds true, then I promise `consequent` will also be true."**
*
* This function is invaluable for defining complex validation logic where one condition dictates another.
*
* ### How It Works
*
* The rule only fails (returns `false`) when the "if" part is `true`, but the "then" part is `false`.
* In all other cases, the promise is considered kept, and the result is `true`.
*
* This includes the concept of **"vacuous truth"**: if the "if" part is `false`, the rule doesn't apply,
* so the promise isn't broken, and the result is `true`. (e.g., "If it rains, I'll bring an umbrella."
* If it doesn't rain, you haven't broken your promise, no matter what).
*
* ### Key Details
*
* - **Logical Equivalence**: `implies(p, q)` is the same as `not(p).or(q)`, or simply `!p || q`
* in plain JavaScript. This can be a helpful way to reason about its behavior.
*
* - **Type-Safety Warning**: This function always returns a `Predicate`, never a type-narrowing
* `Refinement`. A `true` result doesn't guarantee the `consequent` passed (it could be `true`
* simply because the `antecedent` was `false`), so it cannot be used to safely narrow a type.
*
* @example
* ```ts
* // Rule: A user can only be an admin if they also belong to the "staff" group.
* import * as assert from "node:assert"
* import { Predicate } from "effect"
*
* type User = {
* isStaff: boolean
* isAdmin: boolean
* }
*
* const isValidUserPermission = Predicate.implies(
* // antecedent: "if" the user is an admin...
* (user: User) => user.isAdmin,
* // consequent: "then" they must be staff.
* (user: User) => user.isStaff
* )
*
* // A non-admin who is not staff. Rule doesn't apply (antecedent is false).
* assert.strictEqual(isValidUserPermission({ isStaff: false, isAdmin: false }), true)
*
* // A staff member who is not an admin. Rule doesn't apply (antecedent is false).
* assert.strictEqual(isValidUserPermission({ isStaff: true, isAdmin: false }), true)
*
* // An admin who is also staff. The rule was followed.
* assert.strictEqual(isValidUserPermission({ isStaff: true, isAdmin: true }), true)
*
* // An admin who is NOT staff. The rule was broken!
* assert.strictEqual(isValidUserPermission({ isStaff: false, isAdmin: true }), false)
* ```
*
* @category combinators
* @since 2.0.0
*/
<A>(antecedent: Predicate<A>, consequent: Predicate<A>): Predicate<A>;
};
/**
* Combines two predicates with a logical "NOR" (negated OR). The resulting predicate
* returns `true` only if both predicates return `false`.
* This is equivalent to `not(or(p, q))`.
*
* @category combinators
* @since 2.0.0
*/
export declare const nor: {
/**
* Combines two predicates with a logical "NOR" (negated OR). The resulting predicate
* returns `true` only if both predicates return `false`.
* This is equivalent to `not(or(p, q))`.
*
* @category combinators
* @since 2.0.0
*/
<A>(that: Predicate<A>): (self: Predicate<A>) => Predicate<A>;
/**
* Combines two predicates with a logical "NOR" (negated OR). The resulting predicate
* returns `true` only if both predicates return `false`.
* This is equivalent to `not(or(p, q))`.
*
* @category combinators
* @since 2.0.0
*/
<A>(self: Predicate<A>, that: Predicate<A>): Predicate<A>;
};
/**
* Combines two predicates with a logical "NAND" (negated AND). The resulting predicate
* returns `true` if at least one of the predicates returns `false`.
* This is equivalent to `not(and(p, q))`.
*
* @category combinators
* @since 2.0.0
*/
export declare const nand: {
/**
* Combines two predicates with a logical "NAND" (negated AND). The resulting predicate
* returns `true` if at least one of the predicates returns `false`.
* This is equivalent to `not(and(p, q))`.
*
* @category combinators
* @since 2.0.0
*/
<A>(that: Predicate<A>): (self: Predicate<A>) => Predicate<A>;
/**
* Combines two predicates with a logical "NAND" (negated AND). The resulting predicate
* returns `true` if at least one of the predicates returns `false`.
* This is equivalent to `not(and(p, q))`.
*
* @category combinators
* @since 2.0.0
*/
<A>(self: Predicate<A>, that: Predicate<A>): Predicate<A>;
};
/**
* Takes an iterable of predicates and returns a new predicate. The new predicate
* returns `true` if all predicates in the collection return `true` for a given value.
*
* This is like `Array.prototype.every` but for a collection of predicates.
*
* @example
* ```ts
* import * as assert from "node:assert"
* import { Predicate } from "effect"
*
* const isPositive = (n: number) => n > 0
* const isEven = (n: number) => n % 2 === 0
*
* const isPositiveAndEven = Predicate.every([isPositive, isEven])
*
* assert.strictEqual(isPositiveAndEven(4), true)
* assert.strictEqual(isPositiveAndEven(3), false)
* assert.strictEqual(isPositiveAndEven(-2), false)
* ```
*
* @category elements
* @since 2.0.0
* @see some
*/
export declare const every: <A>(collection: Iterable<Predicate<A>>) => Predicate<A>;
/**
* Takes an iterable of predicates and returns a new predicate. The new predicate
* returns `true` if at least one predicate in the collection returns `true` for a given value.
*
* This is like `Array.prototype.some` but for a collection of predicates.
*
* @example
* ```ts
* import * as assert from "node:assert"
* import { Predicate } from "effect"
*
* const isNegative = (n: number) => n < 0
* const isOdd = (n: number) => n % 2 !== 0
*
* const isNegativeOrOdd = Predicate.some([isNegative, isOdd])
*
* assert.strictEqual(isNegativeOrOdd(-2), true) // isNegative is true
* assert.strictEqual(isNegativeOrOdd(3), true) // isOdd is true
* assert.strictEqual(isNegativeOrOdd(4), false) // both are false
* ```
*
* @category elements
* @since 2.0.0
* @see every
*/
export declare const some: <A>(collection: Iterable<Predicate<A>>) => Predicate<A>;
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