Add utilities to check hex values.

diff --git a/src/utils/index.ts b/src/utils/index.ts
index fa4cc8a236cc4b1e71dfec8b275a6b12d825dcd1..795e7d0e7824d26d3c527d2128739aa0e39987ca 100644 (file)
--- a/src/utils/index.ts
+++ b/src/utils/index.ts
@@ -30,6 +30,47 @@ type Averages = {
        truncatedHarmonic: number,
 }
 
+/**
+* Checks if value is a string representing an N-byte hexadecimal number.
+*
+* @param {unknown} value - Value to check.
+* @param {(number|null)} byteLength - Number of bytes the string should represent, or 'null' for any number greater than zero.
+* @returns True if value is a 2N-character hexadecimal string, else false.
+*/
+export function isHexN (value: unknown, byteLength: number | null): value is string {
+       if (typeof value !== 'string') return false
+       const v = value.replace(/^0[Xx]/, '')
+       const length = byteLength === null ? '+' : `{${2 * byteLength}}`
+       const r = new RegExp(`^[A-Fa-f\\d]${length}\$`)
+       return r.test(v)
+}
+
+/**
+* Checks if value is a string representing an 8-byte hexadecimal number.
+*
+* @param {unknown} value - Value to check.
+* @returns True if value is a 16-character hexadecimal string, else false.
+*/
+export function isHex8 (value: unknown): value is string {
+       return isHexN(value, 8)
+}
+
+/**
+* Checks if value is a string representing a 32-byte hexadecimal number.
+*
+* @param {unknown} value - Value to check.
+* @returns True if value is a 64-character hex string, else false.
+*/
+export function isHex32 (value: unknown): value is string {
+       return isHexN(value, 32)
+}
+
+/**
+* Computes various types of averages for a set of numbers.
+*
+* @param {number[]} times - List of numbers, often timing durations.
+* @returns Object with averaged values for the specified list.
+*/
 export function stats (times: number[]): Averages | null {
        if (times == null || times.length === 0) return null