{"record":{"id":"4081e2c2ad00a6c2","repo":"rohitg00/ai-engineering-from-scratch","slug":"shingle-width-must-be-positive","errorCode":null,"errorMessage":"shingle_width must be positive","messagePattern":"shingle_width must be positive","errorType":"validation","errorClass":"ValueError","httpStatus":null,"severity":"error","filePath":"phases/19-capstone-projects/42-large-corpus-downloader/code/main.py","lineNumber":126,"sourceCode":"    The signature uses universal hashing of the form ((a * x + b) mod p) mod 2^64.\n    Two coefficients are derived deterministically from the seed so the family\n    of hash functions is reproducible across runs and machines.\n    \"\"\"\n\n    digest = hashlib.blake2b(seed.to_bytes(8, \"little\"), digest_size=16).digest()\n    a = int.from_bytes(digest[:8], \"little\") | 1  # ensure a is non-zero\n    b = int.from_bytes(digest[8:], \"little\")\n    return a, b\n\n\nclass MinHasher:\n    \"\"\"MinHash signature builder with a fixed family of hash seeds.\"\"\"\n\n    def __init__(self, num_hashes: int = DEFAULT_NUM_HASHES, shingle_width: int = DEFAULT_SHINGLE_WIDTH) -> None:\n        if num_hashes <= 0:\n            raise ValueError(\"num_hashes must be positive\")\n        if shingle_width <= 0:\n            raise ValueError(\"shingle_width must be positive\")\n        self.num_hashes = num_hashes\n        self.shingle_width = shingle_width\n        self._coefficients: list[tuple[int, int]] = [_hash_seed_pair(i) for i in range(num_hashes)]\n\n    def shingles(self, text: str) -> list[str]:\n        \"\"\"Return overlapping whitespace-token shingles.\"\"\"\n\n        tokens = text.split()\n        if len(tokens) < self.shingle_width:\n            return [\" \".join(tokens)] if tokens else []\n        shingles: list[str] = []\n        for start in range(len(tokens) - self.shingle_width + 1):\n            shingles.append(\" \".join(tokens[start : start + self.shingle_width]))\n        return shingles\n\n    @staticmethod\n    def _hash_shingle(shingle: str) -> int:\n        digest = hashlib.blake2b(shingle.encode(\"utf-8\"), digest_size=8).digest()","sourceCodeStart":108,"sourceCodeEnd":144,"githubUrl":"https://github.com/rohitg00/ai-engineering-from-scratch/blob/39ea8a1c6d0b61f071226eff7ede4d4105fed820/phases/19-capstone-projects/42-large-corpus-downloader/code/main.py#L108-L144","documentation":"Error \"shingle_width must be positive\" thrown in rohitg00/ai-engineering-from-scratch.","triggerScenarios":"Thrown at phases/19-capstone-projects/42-large-corpus-downloader/code/main.py:126 when the library encounters an invalid state.","commonSituations":"See trigger scenarios.","solutions":[],"exampleFix":null,"handlingStrategy":null,"validationCode":null,"typeGuard":null,"tryCatchPattern":null,"preventionTips":[],"tags":[],"backgroundTag":null,"analyzedSha":"39ea8a1c6d0b61f071226eff7ede4d4105fed820","analyzedAt":"2026-08-26T03:13:46.626Z","schemaVersion":2},"datasetVersion":"2026-08-26T07:17:17.940Z"}