Jared Hester cloudRoutine

Optimizing a simple problem

I was introduced to a simple optimization problem by one of my interns last week. He was about to participate in a friendly competition where they were asked to find a performant solution to the problem:

The problem

Monadic JSON Transformers

Full source for JSON Transformer: https://gist.github.com/mrange/7c39333de480a8de5c812a1f6ba70173

Full source for XML Transformer: https://gist.github.com/mrange/552cb0b474b517b706333cebb64f44aa

A popular approach in Functional Languages to create parsers is to use parser combinators.

Functional Track talks from NDC Oslo 2016

Wednesday 2016-06-08

Hello software developers,

Please check your code to ensure you're not making one of the following mistakes related to cryptography.

I. General Mistakes

Writing your own home-grown cryptography primitives (For example: Mifare Classic)
- Exception: For the sake of learning, but don't deploy it in production.
Using a fast hash function (e.g. MD5, SHA256) for storing passwords. Use bcrypt instead.
Not using a cryptographically secure random number generator

Make things easy for yourself and start by running posh as admin

If you already have dnvm installed remember to run update-self if you haven't recently

Clone and checkout the coreclr branch of Kevin Ransom's Fork of the Visual F# Compiler and Tools

Installing DNVM

You need DNVM as a starting point. DNVM enables you to acquire a (or multiple) .NET Execution Environment (DNX).

	[<Struct;StructLayout(LayoutKind.Explicit, Pack=1,Size=32)>]
	type Bucket =
	struct
	[<FieldOffset(0)>]val mutable Free : int64
	[<FieldOffset(8)>]val mutable FreeCount: int
	[<FieldOffset(12)>]val mutable Used: int
	[<FieldOffset(16)>]val mutable Size: int
	[<FieldOffset(20)>]val mutable Full: bool
	end

	C:\Program Files (x86)\MSBuild\12.0\Bin\Microsoft.Common.CurrentVersion.targets
	<Target Name="_CheckForInvalidConfigurationAndPlatform"></Target>
	<Target Name="Build" Condition=" '$(_InvalidConfigurationWarning)' != 'true' " DependsOnTargets="$(BuildDependsOn)" Returns="$(TargetPath)" />
	<Target Name="BeforeBuild" />
	<Target Name="AfterBuild" />
	<Target Name="CoreBuild" DependsOnTargets="$(CoreBuildDependsOn)"></Target>
	<Target Name="Rebuild" Condition=" '$(_InvalidConfigurationWarning)' != 'true' " DependsOnTargets="$(RebuildDependsOn)" Returns="$(TargetPath)" />
	<Target Name="BeforeRebuild" />
	<Target Name="AfterRebuild" />
	<Target Name="BuildGenerateSources" DependsOnTargets="BuildGenerateSourcesTraverse;$(BuildGenerateSourcesAction)" />

	// Install-Package -ProviderName nuget SharpDX -Destination $pwd\packages
	#r "packages/SharpDX.2.6.3/Bin/DirectX11-Signed-net40/SharpDX.dll"
	#r "packages/SharpDX.2.6.3/Bin/DirectX11-Signed-net40/SharpDX.D3DCompiler.dll"
	#r "packages/SharpDX.2.6.3/Bin/DirectX11-Signed-net40/SharpDX.DXGI.dll"
	#r "packages/SharpDX.2.6.3/Bin/DirectX11-Signed-net40/SharpDX.Direct3D11.dll"

	open System
	open System.Collections.Generic
	open System.Diagnostics

	open System
	open System.Globalization
	open FParsec

	type Token =
	\| KeyGroup of string list
	\| KeyValue of string * obj

	let (<\|\|>) p1 p2 = attempt (p1 \|>> box) <\|> attempt (p2 \|>> box)
	let spc = many (anyOf [' '; '\t'])

	[<System.Runtime.CompilerServices.Extension>]
	type ExtensionMethods() =
	[<System.Runtime.CompilerServices.Extension>]
	static member inline GetOption< ^a,'k,'v when 'a : (member TryGetValue : 'k * ('v byref) -> bool)>(this : ^a, key : 'k) =
	let mutable v = Unchecked.defaultof<'v>
	let scc = ( ^a : (member TryGetValue : 'k * ('v byref) -> bool) this, key, &v)
	if scc then
	Some v
	else
	None