cartermp

d1egoaz

If you want to learn Scala, I’d suggest:

• Install IntelliJ + Scala Plugin
• Don’t do the Coursera courses yet.
• Don’t do the “red book” Functional Programming in Scala yet.
• Do: http://underscore.io/books/
  • Essential Scala
  • Essential Play
  • Essential Slick
• Do Scala for the Impatient: https://www.amazon.com/Scala-Impatient-Cay-S-Horstmann/dp/0321774094
• The Neophyte’s Guide to Scala http://danielwestheide.com/scala/neophytes.html

swlaschin

Functional Track talks from NDC Oslo 2017

Also, here is the list of all videos from NDC Oslo 2017:

• YouTube
• Vimeo

Wednesday 2017-06-14

swlaschin

Functional Track talks from NDC London 2017

Also, here is the list of all videos from NDC London 2017:

• YouTube
• Vimeo

Wednesday 2017-01-18

mrange

On the topic of 2D array performance in .NET

Full source code can be found here

It popped up a discussion in FSSF Slack over 2D arrays and performance. I thought it could be good to share some performance numbers for different alternatives in .NET.

For this I am computing the matrix product:

let naiveMultiply () =

mrange

On the topic of data locality and performance

Full source code can be found here

It is well-known that a hard disk has a long delay from that we request the data to that we get the data. Usually we measure the hard disk latency in milliseconds which is an eternity for a CPU. The bandwidth of a hard disk is decent good as SSD:s today can reach 1 GiB/second.

What is less known is that RAM has the same characteristics, bad latency with good bandwidth.

You can measure RAM latency and badndwidth using Intel® Memory Latency Checker. On my machine the RAM latency under semi-high load is ~120 ns (The 3r:1w bandwidth is 16GiB/second). This means that the CPU on my machine has to wait for ~400 cycles for data, an eternity.

mrange

Performance comparison of different data pipelines in .NET

Full source code can be found here

Changelog

1. 2016-12-20
2. New performance test - Paul Westcott (@manofstick) made me aware that SeqComposer has a more performant API. SeqComposer2 uses this API.
3. 2016-12-23

vbfox

module DapperFSharp =
    open System.Data.SqlClient
    open System.Dynamic
    open System.Collections.Generic
    open Dapper

    let dapperQuery<'Result> (query:string) (connection:SqlConnection) =
        connection.Query<'Result>(query)
    
    let dapperParametrizedQuery<'Result> (query:string) (param:obj) (connection:SqlConnection) : 'Result seq =

DotNetNerd

[<CLIMutable>] 
type Person = { Name : string; Age : int }

//Nuget: ImpromptuInterface.FSharp

use conn = new SqlCeConnection("Data Source=C:\Databases\MyDB.sdf;Persist Security Info=False;") 
    conn.Open()

    let result = 
        conn.Query("SELECT * FROM People") 

robertpi

namespace MyNamespace

type IMyInterface =
    abstract GetValue: unit -> string

type MyRecord = 
    { MyField1: int
      MyField2: string }
    interface IMyInterface with
        member x.GetValue() = x.MyField2