```ts
/**
 * Parse a semantic version string into its components.
 */
export function parseSemver(
  version: string,
): { major: number; minor: number; patch: number; prerelease: string | null; build: string | null } {
  const semVerRegex =
    /^(?<major>0|[1-9]\d*)\.(?<minor>0|[1-9]\d*)\.(?<patch>0|[1-9]\d*)(?:-(?<prerelease>[0-9A-Za-z-]+))?(?:\+(?<build>[0-9A-Za-z-]+))?$/;
  const match = semVerRegex.exec(version);
  if (!match?.groups) {
    throw new Error(`Invalid semantic version: ${version}`);
  }

  return {
    major: Number(match.groups.major),
    minor: Number(match.groups.minor),
    patch: Number(match.groups.patch),
    prerelease: match.groups.prerelease ?? null,
    build: match.groups.build ?? null,
  };
}
```