David Tchepak dtchepak

Survey CSV exercise

Background

We are surveying developers at a number of sites to find their favourite programming language. Each response from a site is stored in a type that contains the site name, and a map/dictionary of programming languages and the number of votes they received. In C# this could look something like this:

class SurveyResponse {
    public string Site;
 public Dictionary Results;

	using System;
	using NUnit.Framework;

	namespace Workshop
	{
	public static class ReaderExtensions
	{
	public static Func<T, B> Select<T, A, B>(this Func<T, A> reader, Func<A, B> f)
	{
	return t => f(reader(t));

	using System;
	using NUnit.Framework;

	namespace Workshop
	{
	public static class ReaderExtensions
	{
	public static Func<T, B> Select<T, A, B>(this Func<T, A> reader, Func<A, B> f)
	{
	throw new NotImplementedException("TODO: pass example 1 and 2");

	{- LANGUAGE OverloadedStrings -}
	import Control.Applicative ((<*))
	import Data.Functor ((<$))
	import Data.Text (Text)
	import Text.Parsec
	import Text.Parsec.Text (GenParser)
	type Parser = GenParser ()

	defaultDelim :: Parser Char
	defaultDelim = newline <\|> char ',' -- <\|> is "or". default delimiter is newline or comma

	import Data.Char
	import Data.Maybe

	newline = is '\n'
	comma = is ','
	defaultDelim = newline \|\|\| comma
	customDelim = do
	is '/'
	is '/'
	delim <- char

	import Data.Char
	import Data.List
	import Data.Maybe
	import Data.Monoid
	import Data.Traversable (traverse)

	data ProgrammingLanguage
	= CSharp
	\| FSharp
	\| Haskell

	(* This attempt at the problem (https://gist.github.com/dtchepak/5640717) was
	based on some real code I had to write.
	The aim of this particular approach was to have a deterministic column order,
	plus ensure headers and data stayed in the correct order. I ended up with a
	DSL-sort-of-thing to define columns:
	* `col` to make a column with a particular header and selector; and
	* `lookupCol` to make a header and selector to lookup a result for a language.

	This is probably unecessary for this case, but seemed appropriate for the real
	case which had more columns and column types, so I thought I'd try it out here too.

	using System;
	using NUnit.Framework;
	using Shouldly;

	public class Mushroom { }
	public sealed class Xenum : IEquatable<Xenum> {
	private readonly Mushroom _mushroom;
	private readonly string _s;
	private readonly int _a;
	private readonly int _b;

	//monads.js
	//
	exports.bestSellingCategories = function () {
	return [ createCat(42, "MOL", false)
	, createCat(101, "Both kinds", false)
	, createCat(418, "http", true)
	];
	}

	createCat = function(id,name,shh) { return { id: id, name: name, isSecret: shh}; }



	http://cloud.feedly.com/#subscription%2Ffeed%2F%s