ElasticSearch and F#

exampleElastic.fsx

#r "../packages/Elasticsearch.Net.2.0.4/lib/net46/Elasticsearch.Net.dll"
#r "../packages/NEST.2.0.4/lib/net46/Nest.dll"
#r "../packages/Newtonsoft.Json.8.0.2/lib/net45/Newtonsoft.Json.dll"

open System
open System.Linq
open Nest

module Utils = 
    open Microsoft.FSharp.Quotations
    open Microsoft.FSharp.Linq.RuntimeHelpers
    open System.Linq.Expressions

    (* Building expression for linq! 
        http://stackoverflow.com/questions/9134475/expressionfunct-bool-from-a-f-func
    *)
    let toLinq (expr : Expr<'a -> 'b>) = 
        let linq = LeafExpressionConverter.QuotationToExpression expr
        let call = linq :?> MethodCallExpression
        let lambda = call.Arguments.[0] :?> LambdaExpression
        Expression.Lambda<Func<'a, 'b>>(lambda.Body, lambda.Parameters)

type Post() = 
    member val UserId : int = -1 with get, set
    member val PostDate : DateTime = DateTime.MinValue with get, set
    member val PostTest : string = "" with get, set

type Example() = 
    let mutable _client = Unchecked.defaultof<ElasticClient>
    
    do 
        let node = new Uri("http://localhost:9200")
        let settings = new ConnectionSettings(node)
        settings.DefaultIndex("my_blog") |> ignore
        _client <- new ElasticClient(settings)
        let indexSettings = new IndexSettings()
        indexSettings.NumberOfReplicas <- new Nullable<int>(1)
        indexSettings.NumberOfShards <- new Nullable<int>(1)
        let indexName = new IndexName()
        indexName.Name <- "my_blog"
        indexName.Type <- typedefof<Post>
        let indexState = new IndexState()
        indexState.Settings <- indexSettings
        _client.CreateIndex
            (indexName, fun (c : CreateIndexDescriptor) -> c.InitializeUsing(indexState) :> ICreateIndexRequest) 
        |> ignore
    
    member x.InsertData : unit = 
        let newBlogPost = new Post()
        newBlogPost.UserId <- 1
        newBlogPost.PostDate <- DateTime.Now
        newBlogPost.PostTest <- "This is another blog post."
        let newBlogPost2 = new Post()
        newBlogPost2.UserId <- 2
        newBlogPost2.PostDate <- DateTime.Now
        newBlogPost2.PostTest <- "This is a third blog post."
        let newBlogPost3 = new Post()
        newBlogPost3.UserId <- 3
        newBlogPost3.PostDate <- DateTime.Now.AddDays(5.0)
        newBlogPost3.PostTest <- "This is a blog post from the future."
        _client.Index(newBlogPost) |> ignore
        _client.Index(newBlogPost2) |> ignore
        _client.Index(newBlogPost3) |> ignore
    
    member x.GetAllDocuments = _client.Search<Post>().Documents.ToList()
    
    member x.PerformTermQuery = 
        _client.Search<Post>(
            fun (s: SearchDescriptor<Post>) -> 
                s.Query(fun (j:QueryContainerDescriptor<Post>) -> 
                    j.Term(Utils.toLinq(<@ fun (q:Post) -> q.PostTest :> obj @>),"blog")) :> ISearchRequest).Documents.ToList()

    member x.PerformMatchPhrase =
        _client.Search<Post>(
            fun (s: SearchDescriptor<Post>) -> 
                s.Query(fun (q: QueryContainerDescriptor<Post>) -> 
                    q.MatchPhrase(fun (m : MatchPhraseQueryDescriptor<Post>) -> m.Field(Utils.toLinq(<@ fun (q:Post) -> q.PostTest :> obj @>)).Query("this is a third blog post") :> IMatchQuery)) :> ISearchRequest)
                        .Documents.ToList()

    member x.PerformFilter =
        _client.Search<Post>(fun (s:SearchDescriptor<Post>) ->
            s.Query(fun (q:QueryContainerDescriptor<Post>) -> 
                q.Term(Utils.toLinq(<@ fun (q:Post) -> q.PostTest :> obj @>),"blog")
            ).PostFilter(fun (f:QueryContainerDescriptor<Post>) ->
                f.DateRange(fun (r:DateRangeQueryDescriptor<Post>) ->
                    r.Field(Utils.toLinq(<@ fun (q:Post) -> q.PostTest :> obj @>)).GreaterThan(DateMath.FromString("2015-03-08"))
                    :> IDateRangeQuery
                )
            ) :> ISearchRequest
        ).Documents.ToList()


let example = new Example()

example.InsertData

let documents = example.GetAllDocuments

documents
|> Seq.toList
|> List.iter (fun i -> printfn "%A" i.PostTest)

let documents2 = example.PerformTermQuery

documents2
|> Seq.toList
|> List.iter (fun i -> printfn "%A" i.PostTest)

let documents3 = example.PerformMatchPhrase

documents3
|> Seq.toList
|> List.iter (fun i -> printfn "%A" i.PostTest)

let documents4 = example.PerformFilter

documents4
|> Seq.toList
|> List.iter (fun i -> printfn "%A" i.PostTest)