vivainio

open System

module Ast =
    type var = string
    type Expr =
    | Number   of float
    | BinOp    of (float -> float -> float) * Expr * Expr
    | FunApply of var * Expr list
    with
        static member Sum (e1, e2) = BinOp (( + ), e1, e2)

vivainio

open FSharp.Data
open System.IO
type provider = XmlProvider<"./sample.xml">

[<EntryPoint>]
let main argv = 
    let path = @"C:\blah.csproj"
    let f = File.ReadAllText path
    let data = provider.Parse f
    

vivainio

    public class Collector<TKey>
    {
        private HashSet<TKey> seen = new HashSet<TKey>();

        public IEnumerable<TData> CollectBy<TData>(IEnumerable<TData> input, Func<TData, TKey> extractKey)
        {
            foreach (var inp in input)
            {
                var key = extractKey(inp);
                if (seen.Contains(key))

vivainio

open System.IO
open OfficeOpenXml
open System.Data

[<EntryPoint>]
let main argv = 
    let f = FileInfo("test.xlsx")
    use p = new ExcelPackage(f)
    let ws = p.Workbook.Worksheets.Add("testi")
    use dt = new DataTable("mundata")

vivainio

// deprecate a set of properties. Handy e.g. to see bad access in angular directives where TypeScript doesn't help you
class FooClass { ... }

function deprecate(klass: any, props: string[]) {
    props.forEach(prop => {
        Object.defineProperty(klass.prototype, prop, {
            get: () => { debugger; console.log('BAD READ', prop) },
            set: () => console.log('BAD WRITE', prop)
        })
    })

vivainio

[
    { "key": "ctrl+left", "command": "cursorHome" },
    { "key": "ctrl+right", "command": "cursorEnd" }    
]

vivainio

class CheckedTranslate {
    static $inject = ['$rootScope', '$translate']
    constructor(private $rootScope: ng.IRootScopeService, private $translate: ng.translate.ITranslateService) {}
    translate(localizations: any) {
        // obviously this mutates passed localizations object behind your back
        this.$rootScope.$on('$translateChangeSuccess', () => {
            for (var key in localizations) {
                localizations[key] = this.$translate.instant(localizations[key]);
            }
        })

vivainio

emphasis { font-style: italic; }
strong { font-weight: bold; }
header { color: rgba(0, 0, 128, 1); }
comment { color: rgba(96, 139, 78, 1); }
constant.language { color: rgba(86, 156, 214, 1); }
constant.numeric { color: rgba(181, 206, 168, 1); }
constant.regexp { color: rgba(100, 102, 149, 1); }
constant.rgb-value { color: rgba(212, 212, 212, 1); }
entity.name.tag { color: rgba(86, 156, 214, 1); }
entity.name.function { color: rgba(212, 212, 212, 1); }

vivainio

FSharp intro

Why

Less code, little to no C# like source bloat because of:

• Type inference
• Automatic generics
• Functions instead of methods
• seqs and tuples + unpacking (a'la python)
• pattern matching ("switch case" that matches types & unpacks)

vivainio

(f => { 
  try {
    document.write(f("Vampire"));
  }
  catch (e) {}; 
})(function SaveWorld(startup) {
  return world.savedBy(startup);
});