source/core.cpp

@@ -457,6 +457,32 @@ export namespace core {
 
 // Input/output operations.
 export namespace core {
+	/**
+	 * Compares `a` and `b`, returning the difference between them or `0` if they are identical.
+	 */
+	constexpr size compare(slice<u8 const> const & a, slice<u8 const> const & b) {
+		usize const range = min(a.length, b.length);
+
+		for (usize index = 0; index < range; index += 1) {
+			size const difference = static_cast<size>(a[index]) - static_cast<size>(b[index]);
+
+			if (difference != 0) return difference;
+		}
+
+		return static_cast<size>(a.length) - static_cast<size>(b.length);
+	}
+
+	/**
+	 * Copies the contents of `origin` into `target`.
+	 *
+	 * *Note*: safety-checked behavior is triggered if `target` is smaller than `origin`.
+	 */
+	void copy(slice<u8> const & target, slice<u8 const> const & origin) {
+		if (target.length < origin.length) core::unreachable();
+
+		for (usize i = 0; i < origin.length; i += 1) target[i] = origin[i];
+	}
+
 	/**
 	 * Tests the equality of `a` against `b`, returning `true` if they contain identical bytes,
 	 * otherwise `false`.
@@ -470,14 +496,14 @@ export namespace core {
 	}
 
 	/**
-	 * Copies the contents of `origin` into `target`.
+	 * Returns a hash code generated from the values in `bytes`.
-	 *
-	 * *Note*: safety-checked behavior is triggered if `target` is smaller than `origin`.
 	 */
-	void copy(slice<u8> const & target, slice<u8 const> const & origin) {
+	constexpr usize hash(slice<u8 const> const & bytes) {
-		if (target.length < origin.length) core::unreachable();
+		usize hash_code = 5381;
 
-		for (usize i = 0; i < origin.length; i += 1) target[i] = origin[i];
+		for (u8 const byte : bytes) hash_code = ((hash_code << 5) + hash_code) + byte;
+
+		return hash_code;
 	}
 
 	/**