Text tfidfvectorizer saveasync

TfidfVectorizer.SaveAsync

Write a fitted vectorizer out without blocking the caller.

public Task SaveAsync(Stream destination, CancellationToken cancellationToken = default)

Parameters — destination is a writable stream, left open. cancellationToken cancels the write.

Returns — Task, completing when the vectorizer has been written.

Exceptions — InvalidOperationException when nothing has been fitted yet. ArgumentNullException for a null stream. OperationCanceledException when cancelled.

Example — the round trip, asynchronously.

using Lodestar.Text.Vectorization;

static async Task<string> RoundTripAsync()
{
    var tv = new TfidfVectorizer();
    tv.Fit(["the cat eats", "the dog eats"]);

    using var buffer = new MemoryStream();
    await tv.SaveAsync(buffer);
    buffer.Position = 0;

    TfidfVectorizer restored = await TfidfVectorizer.LoadAsync(buffer);
    return restored.GetFeatureNames()[0];
}

string first = RoundTripAsync().GetAwaiter().GetResult();  // => cat

The GetAwaiter().GetResult() is only what lets a synchronous example drive an async one; in async code the call is simply await.

Remarks — as with CountVectorizer.SaveAsync there is no string path overload: opening the file with useAsync: true is the caller's decision, and hiding it here would hide whether the asynchrony reaches the disk.

Applies to — net10.0, netstandard2.0.

See also — TfidfVectorizer.Save, TfidfVectorizer.LoadAsync.