Embeddings sentencepiecevocabulary gethashcode

Development build. This page describes main, not a released package. The latest published Lodestar.Embeddings is 0.4.0 — read its documentation.

SentencePieceVocabulary.GetHashCode

A hash consistent with that equality.

public int GetHashCode()

Returns — int, over the count and the special ids rather than every piece.

Example — equal vocabularies hash alike.

using Lodestar.Embeddings.Tokenization;

SentencePiece[] pieces =
[
    new SentencePiece("<unk>", 0.0, 0),
    new SentencePiece("<s>", 0.0, 1),
    new SentencePiece("▁alpha", -1.5, 2),
    new SentencePiece("▁beta", -2.5, 3),
];
SentencePieceType[] types =
[
    SentencePieceType.Unknown,
    SentencePieceType.Control,
    SentencePieceType.Normal,
    SentencePieceType.Normal,
];
var vocabulary = new SentencePieceVocabulary(pieces, types, UnkId: 0, BosId: 1, EosId: -1, PadId: -1);

var same = new SentencePieceVocabulary(pieces, types, UnkId: 0, BosId: 1, EosId: -1, PadId: -1);

bool equal = vocabulary.Equals(same);  // => True
bool hashesAlike = vocabulary.GetHashCode() == same.GetHashCode();  // => True

Remarks — hashing thirty-two thousand pieces on every call is a cost that buys nothing, so the hash reads the size and the four special ids. Two different vocabularies of the same size and special ids collide, which is permitted: Equals is what decides, and it reads everything.

Applies to — net10.0, netstandard2.0.

See also — SentencePieceVocabulary.Equals.