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IsLiteral<T>

IsLiteral<T> = IsPrimitive<T> extends true ? IsNotFalse<IsLiteralUnion<T>> : false

Defined in: packages/react-querybuilder/src/types/type-fest/is-literal.ts:288

Returns a boolean for whether the given type is a literal type.

Useful for:

  • providing strongly-typed functions when given literal arguments
  • type utilities, such as when constructing parsers and ASTs

Type Parameters​

Type Parameter
T

Example​

import type {IsLiteral} from 'type-fest';

// https://github.com/inocan-group/inferred-types/blob/master/src/types/string-literals/StripLeading.ts
export type StripLeading<A, B> =
	A extends string
		? B extends string
			? IsLiteral<A> extends true
				? string extends B ? never : A extends `${B & string}${infer After}` ? After : A
				: string
			: A
		: A;

function stripLeading<Input extends string, Strip extends string>(input: Input, strip: Strip) {
	return input.replace(`^${strip}`, '') as StripLeading<Input, Strip>;
}

stripLeading('abc123', 'abc');
//=> '123'

const str = 'abc123' as string;

stripLeading(str, 'abc');
//=> string
caution

API documentation is generated from the latest commit on the main branch. It may be somewhat inconsistent with official releases of React Query Builder.