public static MonadZero <TResult> ReplaceBy <TSource, TResult>(
this MonadZero <TSource> @this,
TResult value)
{
Require.NotNull(@this, nameof(@this));
return(@this.Select(_ => value));
}
/// <seealso cref="Apply{TSource, TResult}(MonadZero{Func{TSource, TResult}}, MonadZero{TSource})" />
public static MonadZero <TResult> Gather <TSource, TResult>(
this MonadZero <TSource> @this,
MonadZero <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 MonadZero <TResult> Using <TSource, TResult>(
this MonadZero <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); } }));
}
private static Func <TKey, MonadZero <TInner> > GetKeyLookup <TInner, TKey>(
MonadZero <TInner> inner,
Func <TInner, TKey> innerKeySelector,
IEqualityComparer <TKey> comparer)
{
Debug.Assert(inner != null);
Debug.Assert(innerKeySelector != null);
return(outerKey =>
inner.Select(innerKeySelector)
.Where(innerKey => (comparer ?? EqualityComparer <TKey> .Default).Equals(innerKey, outerKey))
.ContinueWith(inner));
}
/// <seealso cref="MonadZero.Lift{T1, T2, TResult}"/>
public static MonadZero <TResult> ZipWith <T1, T2, TResult>(
this MonadZero <T1> @this,
MonadZero <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))));
}