```typescript
export function parseSemver(version: string): { major: number; minor: number; patch: number; prerelease: string | null; build: string | null } {
    const regex = /^v?(\d+)\.(\d+)\.(\d+)(-(.+))?(\+(.+))?$/;
    const match = version.match(regex);

    if (!match) {
        throw new Error("Invalid semver format");
    }

    const [_, major, minor, patch, prereleaseOpt, buildOpt] = match;

    return {
        major: parseInt(major, 10),
        minor: parseInt(minor, 10),
        patch: parseInt(patch, 10),
        prerelease: prereleaseOpt || null,
        build: buildOpt || null
    };
}
```