 ```ts
export function parseSemver(version: string): { major: number; minor: number; patch: number; prerelease: string | null; build: string | null } {
    const parts = version.match(/^(\d+)\.(\d+)\.(\d+)(?:-([0-9A-Za-z-]+(?:\.[0-9A-Za-z-]+)*))?(?:\+([0-9A-Za-z-]+(?:\.[0-9A-Za-z-]+)*))?$/);
    if (!parts) {
        throw new Error(`Invalid semantic version string: ${version}`);
    }
    const [, major, minor, prerelease, build] = parts;
    return {
        major: parseInt(major, 10),
        minor: parseInt(minor, 10),
        patch: parseInt(parts[3], 10),
        prerelease: prerelease || null,
        build: build || null,
    };
}
```