```ts
/** Parse a semantic version string into components. */
export function parseSemver(version: string): { major: number; minor: number; patch: number; prerelease: string | null; build: string | null } {
    const regex = /^(\d{1,2})\.(\d{1,2})\.(\d{1,2})(?:-(.+?))?(?:\+(.+?))?$/;
    const match = version.match(regex);
    if (match) {
        return {
            major: parseInt(match[1], 10),
            minor: parseInt(match[2], 10),
            patch: parseInt(match[3], 10),
            prerelease: match[4] || null,
            build: match[5] || null
        };
    } else {
        throw new Error(`Invalid semantic version: ${version}`);
    }
}
```