reader spik

reader.cs

void Main()
{
	var id = new Id();
	Func<Id, Customer> customerById = x => new Customer();
	Func<Criteria, CreditHistory> creditHistoryByCriteria = x => new CreditHistory();
	Func<Report, Unit> print = x => new Unit();
	
	var history = GetCustomer(id)
		.Map(GetCustomerCreditHistory)
		.Uncurry()
		.Map(PrintReport)
		(customerById, creditHistoryByCriteria)
		(print);		
}

Func<Func<Criteria, CreditHistory>, CreditHistory> GetCustomerCreditHistory(Customer customer) => 
	getCreditHistory => getCreditHistory(new Criteria {Context = customer.ToString()})

Func<Func<Id, Customer>, Customer> GetCustomer(Id id) => 
	getCustomer => getCustomer(id);	
	
Func<Func<Report, Unit>, Unit> PrintReport(CreditHistory r) => print => 
	print(new Report(r));

public static class Ex
{
	public static Func<A, B, C> Uncurry<A, B, C>(this Func<A, Func<B,C>> f_a_f_b_c) => (a,b) => f_a_f_b_c(a)(b);
	
	// (A<T>, T -> R) -> A<R>
	// where A : Func<Env,_>
	public static Func<Env,B> Map<Env, A, B>(
		this Func<Env,A> fun_e_a, 
		Func<A, B> f_a_b) => 
		env => f_a_b(fun_e_a(env));

	public static Func<Env1, Env2, B> Map<Env1, Env2, A, B>(
		this Func<Env1, Env2, A> fun_e_a,
		Func<A, B> f_a_b) =>
		(env1, env2) => f_a_b(fun_e_a(env1, env2));

	// (A<T>, T -> A<R>) -> A<R>
	// where A : Func<Env,_>
	public static Func<Env, B> Bind<Env, A, B>(
		this Func<Env, A> fun_e_a, 
		Func<A, Func<Env,B>> f_a_f_e_b) => 
		env => f_a_f_e_b(fun_e_a(env))(env);

	public static Func<Env, C> Bind<Env, A, B, C>(
		this Func<Env, A> fun_e_a, 
		Func<A, Func<Env,B>> f_a_f_e_b, 
		Func<A,B,C> f_a_b_c) =>
		env => f_a_b_c(fun_e_a(env), f_a_f_e_b(fun_e_a(env))(env));
}

class Id { }
class Customer { }
class Criteria
{
	public string Context { get; set; }
}
class Report
{
	public Report(CreditHistory c)
	{

	}
}
class Unit { }
class CreditHistory { }