Type-Level Exponentiation in TypeScript
This challenge involves implementing exponentiation directly at the TypeScript type level. You'll be creating a type that can calculate Base ^ Exponent for non-negative integer Base and Exponent types. This is a fundamental exercise in exploring the expressive power of TypeScript's advanced type manipulation, useful for building complex type-safe libraries and domain-specific languages.
Problem Description
Your task is to define a TypeScript type TypeLevelExponentiation<Base extends number, Exponent extends number> that computes the result of Base raised to the power of Exponent at compile time.
Key Requirements:
- The
BaseandExponentwill be positive integers (represented asnumberliterals in TypeScript types). - The type should handle the base case where
Exponentis 0, in which case the result is 1. - The type should recursively apply multiplication for positive exponents.
- Consider edge cases like
Base = 0andExponent = 0.
Expected Behavior:
The type TypeLevelExponentiation<B, E> should resolve to a number literal representing B ^ E.
Edge Cases to Consider:
TypeLevelExponentiation<any, any>: While the problem focuses on number literals, think about how the type might behave withany. (For this challenge, assume valid number literals).- Large exponents: TypeScript's recursive depth can be a limitation. For this challenge, focus on correctness for reasonably sized exponents that won't hit compiler limits.
- Negative exponents: Not required for this challenge. Assume
Exponent >= 0. - Non-integer bases/exponents: Not required. Assume integer literals.
Examples
Example 1:
type Result1 = TypeLevelExponentiation<2, 3>;
// Expected: Result1 should be type 8
Explanation: 2 ^ 3 is calculated as 2 * 2 * 2 = 8.
Example 2:
type Result2 = TypeLevelExponentiation<5, 0>;
// Expected: Result2 should be type 1
Explanation: Any non-zero number raised to the power of 0 is 1.
Example 3:
type Result3 = TypeLevelExponentiation<0, 5>;
// Expected: Result3 should be type 0
Explanation: 0 raised to any positive power is 0.
Example 4:
type Result4 = TypeLevelExponentiation<1, 10>;
// Expected: Result4 should be type 1
Explanation: 1 raised to any power is 1.
Example 5:
type Result5 = TypeLevelExponentiation<0, 0>;
// Expected: Result5 should be type 1
Explanation: Conventionally, 0^0 is considered 1 in many mathematical contexts, particularly in combinatorics and polynomial expansions.
Constraints
BaseandExponentwill be non-negative integer number literals (e.g.,0,1,5,10).- The solution should only use TypeScript's type system features. No runtime code is involved.
- Focus on correctness for exponents up to a reasonable limit (e.g., 10-15) to avoid hitting TypeScript's recursion depth limits.
Notes
This problem requires understanding and applying recursive type definitions. You'll likely need a helper type to manage the multiplication process. Consider how to decrement the exponent in each recursive step and how to accumulate the result. The base case of Exponent = 0 is crucial for terminating the recursion.