Fuzzy process extract

Process.Extract

The best candidates, ranked.

public static IReadOnlyList<ExtractResult> Extract(string query, IEnumerable<string> choices, Func<string, string, double> scorer = null, int? limit = 5, double scoreCutoff = 0)

Parameters — query is what to match. choices are the candidates. scorer is the scoring function, Fuzz.WRatio when omitted. limit caps how many come back, 5 by default and null for all of them. scoreCutoff drops anything scoring below it.

Returns — IReadOnlyList<ExtractResult>, best first, at most limit long.

Example — the two best of four candidates.

using Lodestar.Fuzzy;

string[] choices = ["apple pie", "apple tart", "banana bread", "cherry pie"];

IReadOnlyList<ExtractResult> best = Process.Extract("apple pie", choices, limit: 2);

int returned = best.Count;  // => 2
string first = best[0].Choice;  // => apple pie
int where = best[0].Index;  // => 0

Remarks — the default limit of 5 is rapidfuzz's, and it is a cap rather than a guarantee: fewer come back when fewer clear the cutoff, and passing null returns every candidate ranked, which on a large list is the expensive call.

scoreCutoff is worth setting rather than filtering afterwards: it lets the scorer abandon a candidate early, so it is faster as well as shorter.

Each result carries its Index, which is how a match is traced back to the record it came from rather than to the string.

Applies to — net10.0, netstandard2.0.

See also — Process.ExtractOne, ExtractResult.