F# Weekly #39, 2013

Welcome to F# Weekly,

A roundup of F# content from this past week:




That’s all for now.  Have a great week.

Previous F# Weekly edition – #38

Dropbox for .NET developers

Some days ago, I was faced with the task of developing Dropbox connector that should be able to enumerate and download files from Dropbox. The ideal case for me is a wrapper library for .NET 3.5 with an ability to authorize in Dropbox without user interaction. This is a list of .NET libraries/components that are currently available:

Sprint.NET and Xamarin component are not my options for now. DropNet also does not fit my needs, because it is .NET 4+ only. But if your application is for .NET 4+, then DropNet should be the best choice for you. I chose SharpBox, it looks like a dead project – no commits since 2011, but nevertheless the latest version is available on NuGet.

At the beginning, you need to go to Dropbox App Console and create a new app. Click on “Create app” button and answer to the questions like in the picture below.


When you finish all these steps, you will get an App key and App secret, please copy them somewhere – you will need them in future. Now we are ready to create our application. Let’s create a new F# project and add AppLimit.CloudComputing.SharpBox package from NuGet.

After package is downloaded, go to packages\AppLimit.CloudComputing.SharpBox.\lib\net40-full folder, find and start DropBoxTokenIssuer.exe application.


Fill Application Key and Application Secret with values that you received during app creation, fill Output-File path with c:\token.txt and click “Authorize”. Wait some seconds(depends on your Internet connection) and follow the steps that will appear in browser control on the form – you will need to authorize in Dropbox with your Dropbox account and grant access to your files for your app. When file with your token will be created, you can click on “Test Token” button to make sure that it is correct.

Using token file, you are able to work with Dropbox files without direct user interaction, as shown in the sample below:

open System.IO
open AppLimit.CloudComputing.SharpBox

let main argv =
    let dropBoxStorage = new CloudStorage()
    let dropBoxConfig = CloudStorage.GetCloudConfigurationEasy(nSupportedCloudConfigurations.DropBox)
    // load a valid security token from file
    use fs = File.Open(@"C:\token.txt", FileMode.Open, FileAccess.Read, FileShare.None)
    let accessToken = dropBoxStorage.DeserializeSecurityToken(fs)
    // open the connection
    let storageToken = dropBoxStorage.Open(dropBoxConfig, accessToken);

    for folder in dropBoxStorage.GetRoot() do
        printfn "%s" (folder.Name)


F# Weekly #38, 2013

Welcome to F# Weekly,

A roundup of F# content from this past week:




That’s all for now.  Have a great week.

Previous F# Weekly edition – #37

F# Weekly #37 2013

Welcome to F# Weekly,

A roundup of F# content from this past week:



That’s all for now.  Have a great week.

Previous F# Weekly edition – #36

Stanford Word Segmenter is available on NuGet

Update (2014, January 3): Links and/or samples in this post might be outdated. The latest version of samples are available on new Stanford.NLP.NET site.


Tokenization of raw text is a standard pre-processing step for many NLP tasks. For English, tokenization usually involves punctuation splitting and separation of some affixes like possessives. Other languages require more extensive token pre-processing, which is usually called segmentation.

The Stanford Word Segmenter currently supports Arabic and Chinese. The provided segmentation schemes have been found to work well for a variety of applications.

One more tool from Stanford NLP Software Package become ready on NuGet today. It is a Stanford Word Segmenter. This is a fourth one Stanford NuGet package published by me, previous ones were a “Stanford Parser“, “Stanford Named Entity Recognizer (NER)” and “Stanford Log-linear Part-Of-Speech Tagger“. Please follow next steps to get started:

F# Sample

For more details see source code on GitHub.

open java.util
open edu.stanford.nlp.ie.crf

let main argv =
if (argv.Length <> 1) then
printf "usage: StanfordSegmenter.Csharp.Samples.exe filename"
let props = Properties();
props.setProperty("sighanCorporaDict", @"..\..\..\..\temp\stanford-segmenter-2013-06-20\data") |> ignore
props.setProperty("serDictionary", @"..\..\..\..\temp\stanford-segmenter-2013-06-20\data\dict-chris6.ser.gz") |> ignore
props.setProperty("testFile", argv.[0]) |> ignore
props.setProperty("inputEncoding", "UTF-8") |> ignore
props.setProperty("sighanPostProcessing", "true") |> ignore

let segmenter = CRFClassifier(props)
segmenter.loadClassifierNoExceptions(@"..\..\..\..\temp\stanford-segmenter-2013-06-20\data\ctb.gz", props)

C# Sample

For more details see source code on GitHub.

using java.util;
using edu.stanford.nlp.ie.crf;

namespace StanfordSegmenter.Csharp.Samples
class Program
static void Main(string[] args)
if (args.Length != 1)
System.Console.WriteLine("usage: StanfordSegmenter.Csharp.Samples.exe filename");

var props = new Properties();
props.setProperty("sighanCorporaDict", @"..\..\..\..\temp\stanford-segmenter-2013-06-20\data");
props.setProperty("serDictionary", @"..\..\..\..\temp\stanford-segmenter-2013-06-20\data\dict-chris6.ser.gz");
props.setProperty("testFile", args[0]);
props.setProperty("inputEncoding", "UTF-8");
props.setProperty("sighanPostProcessing", "true");

var segmenter = new CRFClassifier(props);
segmenter.loadClassifierNoExceptions(@"..\..\..\..\temp\stanford-segmenter-2013-06-20\data\ctb.gz", props);

F# Weekly #36 2013

Welcome to F# Weekly,

A roundup of F# content from this past week:




That’s all for now.  Have a great week.

Previous F# Weekly edition – #35

F# Weekly #35 2013

Welcome to F# Weekly,

A roundup of F# content from this past week:




P.S. 100 Most Influential Books According to Stack Overflow.

That’s all for now.  Have a great week.

Previous F# Weekly edition – #34

MSR-SPLAT Overview for F# (.NET NLP)

Some weeks ago, Microsoft Research announced NLP toolkit called MSR SPLAT. It is time to play with it and take a look what it can do.

Statistical Parsing and Linguistic Analysis Toolkit is a linguistic analysis toolkit. Its main goal is to allow easy access to the linguistic analysis tools produced by the Natural Language Processing group at Microsoft Research. The tools include both traditional linguistic analysis tools such as part-of-speech taggers and parsers, and more recent developments, such as sentiment analysis (identifying whether a particular of text has positive or negative sentiment towards its focus)

SPLAT has a nice Silverlight DEMO app that lets you try all available functionality.


SPLAT also has WCF and RESTful endpoints, but if you want to use them, you need to request an access key(please email to Pallavi Choudhury). For more details, please read an overview article “MSR SPLAT, a language analysis toolkit“.

Important links:

Test Drive

I have received my GUID with example of using Json service from C# that you can find below.

private static void CallSplatJsonService()
    var requestStr = String.Format("http://msrsplat.cloudapp.net/SplatServiceJson.svc/Analyzers?language={0}&json=x", "en");

    string language = "en";
    string input = "I live in Seattle";
    string analyzerList = "POS_tags,Tokens";

    string requestAnanlyse = String.Format("http://msrsplat.cloudapp.net/SplatServiceJson.svc/Analyze?language={0}&analyzers={1}&appId={2}&json=x&input={3}",
        language, analyzerList, appId, input);

    var request = WebRequest.Create(requestAnanlyse);
    request.ContentType = "application.json; charset=utf-8";
    request.Method = "GET";
    string postData = String.Format("/{0}?language={1}&json=x","Analyzers", "en");

    using(Stream s = request.GetResponse().GetResponseStream())
        using(StreamReader sr = new StreamReader(s))
            var jsonData = sr.ReadToEnd();

In following samples, I used WCF endpoint since WsdlService Type Provider can dramatically simplify access to the service.

#r "FSharp.Data.TypeProviders.dll"
#r "System.ServiceModel.dll"
#r "System.Runtime.Serialization.dll"
open System
open Microsoft.FSharp.Data.TypeProviders

type MSRSPLAT = WsdlService<"http://msrsplat.cloudapp.net/SplatService.svc?wsdl">
let splat = MSRSPLAT.GetBasicHttpBinding_ISplatService()

In the first call we ask the SPLAT to return list of supported languages splat.Languages() and you will see [|”en”; “bg”|] (English and Bulgarian). The mystical Bulgaria… I do not know why, but NLP guys like Bulgaria. There is something special for NLP :).

The next call is splat.Analyzers(“en”) that returns list of all analyzers that are available for English language (All of them are available from DEMO app)

  • Base Forms-LexToDeriv-DerivFormsC#”
  • Chunker-SpecializedChunks-ChunkerC++”
  • Constituency_Forest-PennTreebank3-SplitMerge”
  • Constituency_Tree-PennTreebank3-SplitMerge”
  • Constituency_Tree_Score-Score-SplitMerge”
  • CoRef-PennTreebank3-UsingMentionsAndHeadFinder”
  • Dependency_Tree-PennTreebank3-ConvertFromConstTree”
  • Katakana_Transliterator-Katakana_to_English-Perceptron”
  • Lemmas-LexToLemma-LemmatizerC#”
  • Named_Entities-CONLL-CRF”
  • POS_Tags-PennTreebank3-cmm”
  • Semantic_Roles-PropBank-kristout”
  • Semantic_Roles_Scores-PropBank-kristout”
  • Sentiment-PosNeg-MaxEntClassifier”
  • Stemmer-PorterStemmer-PorterStemmerC#”
  • Tokens-PennTreebank3-regexes”
  • Triples-SimpleTriples-ExtractFromDeptree”

This is a list of full names of analyzers that are available for now. The part of the analyzer’s name that you have to pass to the service to perform corresponding analysis is highlighted in bold. To perform the analysis, you need to have an access guid and pass it as an email to splat.Analyze method. It is probably a typo, but as it is.  Let’s call all analyzers on the one of our favorite sentences “All your types are belong to us” and look at the result.


let analyzers = String.Join(",", splat.Analyzers("en")
                |> Array.map (fun s -> s.Split([|'-'|]).[0]))
let text = "All your types are belong to us"
let bag = splat.Analyze("en", analyzers, text, appId)


The result is

  "["[NP All your types] [VP are] [VP belong] [PP to] [NP us] \u000a"]";
  "["@@All your types are belong to us\u000d\u000a0\u0009G_DT..."]";
  "["(TOP (S (NP (PDT All) (PRP$ your) (NNS types)) (VP (VBP are) (VP (VB belong) (PP (TO to) (NP (PRP us)))))))"]";
  "["14.50%: アリオータイプサレベロングタス","13.27%: オールユアタイプサレベロングタス","13.26%: アルユアタイプサレベロングタス","13.26%: アリオールタイプサレベロングタス","11.34%: アリオウルタイプサレベロングタス","7.81%: アルルユアタイプサレベロングタス","7.10%: アリアウータイプサレベロングタス","6.60%: アリアウルタイプサレベロングタス","6.46%: アリーオータイプサレベロングタス","6.40%: アリオータイプサリベロングタス"]";
  "[["4-4\/belong[A1=0-2\/All_your_types, A1=5-6\/to_us]"]]";
  "[["are_belong_to(types, us)"]]"|]

As you see, service returns result as string[]. All result strings are readable for human eyes and formatted according to “NLP standards”, but some of them are really hard to parse programmatically. FSharp.Data and JSON Type Provider can help with strings that contain correct Json objects.

For example, if you need to use “Sentiment-PosNeg-MaxEntClassifier” analyzer in strongly typed way, then you can do it as follows:

#r @"..\packages\FSharp.Data.1.1.9\lib\net40\FSharp.Data.dll"
open FSharp.Data

type SentimentsProvider = JsonProvider<""" {"Classification":"pos","Probability":0.59141720028208355} """>

let bag2 = splat.Analyze("en", "Sentiment", "I love F#.", appId)
let sentiments = SentimentsProvider.Parse(bag2.Analyses.[0])

printfn "Class:'%s' Probability:'%M'"
    (sentiments.Classification) (sentiments.Probability)

For analyzers like “Constituency_Tree-PennTreebank3-SplitMerge” you need to write custom parser that proceses bracket expression (“(TOP (S (NP (PDT All) (PRP$ your) (NNS types)) (VP (VBP are) (VP (VB belong) (PP (TO to) (NP (PRP us)))))))”) and builds a tree for you. If you are lazy to do it yourself (you should be so), you can download  SilverlightSplatDemo.xap and decompile source code. All parsers are already implemented there for DEMO app. But this approach is not so easy as it should be.


MSR SPLAT looks like a really powerful and promising toolkit. I hope that it continues growing.

The only wish is an API improvement. I think there should be possible to use services in a strongly typed way. The easiest way is to add an ability to get all results as Json without any cnf forms and so on. Also it can be achieved by changing WCF service and exposing analysis results in a typed way instead of string[].