public static RWS <R, W, S, C> M <R, W, S, A, B, C>(RWS <R, W, S, A> ma, RWS <R, W, S, B> mb, Func <A, B, C> liftFn)
where S : class
{
return(from a in ma
from b in mb
select liftFn(a, b));
}
/// <summary>
/// Select Many
/// </summary>
public static RWS <R, W, S, V> SelectMany <R, W, S, T, U, V>(
this RWS <R, W, S, T> self,
Func <T, RWS <R, W, S, U> > bind,
Func <T, U, V> project
)
where S : class
{
if (bind == null)
{
throw new ArgumentNullException("bind");
}
if (project == null)
{
throw new ArgumentNullException("project");
}
return((R r, S s) =>
{
var resT = self(r, s);
var resU = bind(resT.Value).Invoke(r, resT.State ?? s);
var resV = project(resT.Value, resU.Value);
return RWSResult.Create <W, S, V>(resV, resT.Output.Concat(resU.Output), resU.State ?? resT.State ?? s);
});
}
public static RWS <R, W, S, D> M <R, W, S, A, B, C, D>(RWS <R, W, S, A> ma, RWS <R, W, S, B> mb, RWS <R, W, S, C> mc, Func <A, B, C, D> liftFn)
where S : class
{
return(from a in ma
from b in mb
from c in mc
select liftFn(a, b, c));
}
public static RWS <R, W, S, R> Ask <R, W, S, T>(this RWS <R, W, S, T> self, Func <R, R> f)
{
if (f == null)
{
throw new ArgumentNullException("f");
}
return((R r, S s) => RWSResult.Create(f(r), new W[0], s));
}
/// <summary>
/// Select
/// </summary>
public static RWS <R, W, S, U> Select <R, W, S, T, U>(this RWS <R, W, S, T> self, Func <T, U> select)
where S : class
{
if (select == null)
{
throw new ArgumentNullException("select");
}
return((R r, S s) =>
{
var resT = self(r, s);
var resU = select(resT.Value);
return RWSResult.Create <W, S, U>(resU, resT.Output, resT.State ?? s);
});
}
public static RWS <R, W, S, U> M <R, W, S, T, U>(RWS <R, W, S, T> m, Func <T, U> liftFn)
where S : class
{
return(from v in m select liftFn(v));
}
public static RWS <R, W, S, IO <U> > IO <R, W, S, T, U>(RWS <R, W, S, IO <T> > m, Func <T, U> liftFn)
where S : class
{
return(from v in m select Lift.M(v, liftFn));
}
/// <summary>
/// Memoize the result
/// </summary>
public static Func <RWSResult <W, S, T> > Memo <R, W, S, T>(this RWS <R, W, S, T> self, R r, S s)
{
var res = self(r, s);
return(() => res);
}
public static RWS <R, W, S, R> Ask <R, W, S, T>(this RWS <R, W, S, T> self)
{
return((R r, S s) => RWSResult.Create(r, new W[0], s));
}
