example of how to use synonyms in nest - elasticsearch

Question

i haven't found a solid example on how to create and use synonyms using Nest for Elasticsearch. if anyone has one it would be helpful.
my attempt looks like this, but i don't know how to apply it to a field.
var syn = new SynonymTokenFilter
{
Synonyms = new [] { "pink, p!nk => pink", "lil, little", "ke$ha, kesha => ke$ha" },
IgnoreCase = true,
Tokenizer = "standard"
};
client.CreateIndex("myindex", i =>
{
i
.Analysis(a => a.Analyzers(an => an
.Add("fullTermCaseInsensitive", fullTermCaseInsensitive)
)
.TokenFilters(x => x
.Add("synonym", syn)
)
)
...

Answer 1

it's very simple :)
you will need to define first the Synonym filter the you can use it in your custom Analyzer...where you can add also other type of filters.
Small example :
.Analysis(descriptor => descriptor
.Analyzers(bases => bases
.Add("folded_word", new CustomAnalyzer()
{
Filter = new List<string> { "icu_folding", "trim", "synonym" },
Tokenizer = "standard"
}
)
)
.TokenFilters(i => i
.Add("synonym", new SynonymTokenFilter()
{
SynonymsPath="analysis/synonym.txt",
Format = "Solr"
}
)
)
Then you can use the custom analyzer in the mapping part

Answer 2

Assuming your fullTermCaseInsensitive analyzer is custom, you need to add your synonym filter to it:
var fullTermCaseInsensitive = new CustomAnalyzer()
{
.
.
.
Filter = new string[] { "syn" }
};
And upon creating your index, you can add a mapping and apply the fullTermCaseInsensitive analyzer to your field(s):
client.CreateIndex("myindex", c => c
.Analysis(a => a
.Analyzers(an => an.Add("fullTermCaseInsensitive", fullTermCaseInsensitive))
.TokenFilters(tf => tf.Add("syn", syn)))
.AddMapping<MyType>(m => m
.Properties(p => p
.String(s => s.Name(t => t.MyField).Analyzer("fullTermCaseInsensitive")))));