/// <seealso cref="Monad.Lift{T1, T2, T3, T4, T5, TResult}"/>
public static Monad <TResult> ZipWith <T1, T2, T3, T4, T5, TResult>(
this Monad <T1> @this,
Monad <T2> second,
Monad <T3> third,
Monad <T4> fourth,
Monad <T5> fifth,
Func <T1, T2, T3, T4, T5, TResult> zipper)
{
Require.NotNull(@this, nameof(@this));
Require.NotNull(second, nameof(second));
Require.NotNull(third, nameof(third));
Require.NotNull(fourth, nameof(fourth));
Require.NotNull(fifth, nameof(fifth));
Require.NotNull(zipper, nameof(zipper));
// > return @this.Bind(
// > arg1 => second.Bind(
// > arg2 => third.Bind(
// > arg3 => fourth.Bind(
// > arg4 => fifth.Select(
// > arg5 => zipper(arg1, arg2, arg3, arg4, arg5))))));
return(@this.Bind(
arg1 => second.ZipWith(
third,
fourth,
fifth,
(arg2, arg3, arg4, arg5) => zipper(arg1, arg2, arg3, arg4, arg5))));
}
public static Monad <TSource> PassBy <TSource, TOther>(
this Monad <TSource> @this,
Monad <TOther> other)
{
Require.NotNull(@this, nameof(@this));
return(@this.ZipWith(other, (arg, _) => arg));
}
public static Monad <TResult> ContinueWith <TSource, TResult>(
this Monad <TSource> @this,
Monad <TResult> other)
{
Require.NotNull(@this, nameof(@this));
return(@this.Bind(_ => other));
}
public static Monad <TResult> ReplaceBy <TSource, TResult>(
this Monad <TSource> @this,
TResult value)
{
Require.NotNull(@this, nameof(@this));
return(@this.Select(_ => value));
}
/// <seealso cref="Gather{TSource, TResult}" />
public static Monad <TResult> Apply <TSource, TResult>(
this Monad <Func <TSource, TResult> > @this,
Monad <TSource> value)
{
Require.NotNull(value, nameof(value));
return(value.Gather(@this));
}
public static Monad <TResult> Select <TSource, TResult>(
this Monad <TSource> @this,
Func <TSource, TResult> selector)
{
Require.NotNull(@this, nameof(@this));
Require.NotNull(selector, nameof(selector));
return(@this.Bind(val => Monad <TResult> .η(selector(val))));
}
/// <seealso cref="Apply{TSource, TResult}(Monad{Func{TSource, TResult}}, Monad{TSource})" />
public static Monad <TResult> Gather <TSource, TResult>(
this Monad <TSource> @this,
Monad <Func <TSource, TResult> > applicative)
{
Require.NotNull(@this, nameof(@this));
Require.NotNull(applicative, nameof(applicative));
return(applicative.Bind(func => @this.Select(func)));
}
// Select() with automatic resource management.
public static Monad <TResult> Using <TSource, TResult>(
this Monad <TSource> @this,
Func <TSource, TResult> selector)
where TSource : IDisposable
{
Require.NotNull(@this, nameof(@this));
Require.NotNull(selector, nameof(selector));
return(@this.Select(val => { using (val) { return selector(val); } }));
}
// Bind() with automatic resource management.
public static Monad <TResult> Using <TSource, TResult>(
this Monad <TSource> @this,
Func <TSource, Monad <TResult> > binder)
where TSource : IDisposable
{
Require.NotNull(@this, nameof(@this));
Require.NotNull(binder, nameof(binder));
return(@this.Bind(val => { using (val) { return binder(val); } }));
}
// Generalizes both Bind() and ZipWith<T1, T2, TResult>().
public static Monad <TResult> SelectMany <TSource, TMiddle, TResult>(
this Monad <TSource> @this,
Func <TSource, Monad <TMiddle> > selector,
Func <TSource, TMiddle, TResult> resultSelector)
{
Require.NotNull(@this, nameof(@this));
Require.NotNull(selector, nameof(selector));
Require.NotNull(resultSelector, nameof(resultSelector));
return(@this.Bind(
val => selector(val).Select(
middle => resultSelector(val, middle))));
}
/// <seealso cref="Monad.Lift{T1, T2, TResult}"/>
public static Monad <TResult> ZipWith <T1, T2, TResult>(
this Monad <T1> @this,
Monad <T2> second,
Func <T1, T2, TResult> zipper)
{
Require.NotNull(@this, nameof(@this));
Require.NotNull(second, nameof(second));
Require.NotNull(zipper, nameof(zipper));
return(@this.Bind(
arg1 => second.Select(
arg2 => zipper(arg1, arg2))));
}
/// <seealso cref="Monad.Lift{T1, T2, T3, TResult}"/>
public static Monad <TResult> ZipWith <T1, T2, T3, TResult>(
this Monad <T1> @this,
Monad <T2> second,
Monad <T3> third,
Func <T1, T2, T3, TResult> zipper)
{
Require.NotNull(@this, nameof(@this));
Require.NotNull(second, nameof(second));
Require.NotNull(third, nameof(third));
Require.NotNull(zipper, nameof(zipper));
// This is the same as:
// > return @this.Bind(
// > arg1 => second.Bind(
// > arg2 => third.Select(
// > arg3 => zipper(arg1, arg2, arg3))));
// but faster if ZipWith is locally shadowed.
return(@this.Bind(
arg1 => second.ZipWith(
third, (arg2, arg3) => zipper(arg1, arg2, arg3))));
}
internal static Monad <T> μ(Monad <Monad <T> > square) => square.Bind(Stubs <Monad <T> > .Ident);
public static Monad <unit> Skip <TSource>(this Monad <TSource> @this)
{
Require.NotNull(@this, nameof(@this));
return(@this.ContinueWith(Monad.Unit));
}
/// <summary> /// Removes one level of structure, projecting its bound value into the outer level. /// </summary> public static Monad <T> Flatten <T>(this Monad <Monad <T> > @this) => Monad <T> .μ(@this);
