Getting Started

Getting started

The best way to start with suggest package is to write some working example.

First of all, we should download suggest package via go get command.

$ go get github.com/suggest-go/suggest

We should specify the dictionary on which we are going to perform approximate string search. Here we use InMemoryDictionary, that holds all dictionary items in RAM memory.

dict := dictionary.NewInMemoryDictionary([]string{
    "Nissan March",
    "Nissan Juke",
    "Nissan Maxima",
    "Nissan Murano",
    "Nissan Note",
    "Toyota Mark II",
    "Toyota Corolla",
    "Toyota Corona",
})

We have to tell suggest package how to build the search index for the dictionary above.

indexDescription := suggest.IndexDescription {
    Name:      "cars",
    NGramSize: 3,
    Wrap:      [2]string{"$", "$"},
    Pad:       "$",
    Alphabet:  []string{"english", "$"},
}

where

Name - is the dictionary name. suggest provides fuzzy search support for multiple dictionaries.
NGramSize - is the size of n-grams.
Wrap - is a [2]string array, where the first and the last elements are used for wrapping each dictionary word. It allows searching candidates with more precision.
Pad - Symbols that are not in the Alphabet, will be replaced with the pad.
Alphabet - is a allowed sequence of characters.

Create index builder, service. Here we create Runtime index builder, which will build search index on fly. (otherwise we should create a search index with indexer cli)

builder, err := suggest.NewRAMBuilder(dict, indexDescription)

if err != nil {
    log.Fatalf("Unexpected error: %v", err)
}

service := suggest.NewService()

if err := service.AddIndex(indexDescription.Name, dict, builder); err != nil {
    log.Fatalf("Unexpected error: %v", err)
}

And it is all. Now to perform a query to the service, we do the next:

// declare a search configuration (query, topK elements, type of metric, min similarity)
searchConf, err := suggest.NewSearchConfig("niss ma", 5, metric.CosineMetric(), 0.4)

if err != nil {
    log.Fatalf("Unexpected error: %v", err)
}

result, err := service.Suggest("cars", searchConf)

if err != nil {
    log.Fatalf("Unexpected error: %v", err)
}

values := make([]string, 0, len(result))

for _, item := range result {
    values = append(values, item.Value)
}

fmt.Println(values)
// Output: [Nissan Maxima Nissan March]