public static CondAsync <A, C> Select <A, B, C>(this Cond <A, B> self, Func <B, Task <C> > map) =>
input =>
from b in self.ToAsync()(input)
from c in b.Match(
Some: b2 => map(b2).ContinueWith(b3 => Optional(b3.Result)),
None: () => Option <C> .None.AsTask())
select c;
public static Func <A, Task <B> > Else <A, B>(this Cond <A, B> self, Task <B> Else) =>
input =>
from b in self.ToAsync()(input)
from c in b.Match(
Some: c1 => c1.AsTask(),
None: () => Else)
select c;
public static Func <Task <A>, Task <B> > ElseAsync <A, B>(this Cond <A, B> self, Func <Task <B> > Else) =>
input =>
from a in input
from b in self.ToAsync()(a)
from c in b.Match(
Some: c1 => c1.AsTask(),
None: () => Else())
select c;
public static CondAsync <A, B> All <A, B>(this Cond <A, B> self, params Func <B, Task <bool> >[] predicates) =>
input =>
from x in self.ToAsync()(input)
from y in x.Match(
Some: b => Tasks.ForAll(predicates.Map(p => p(b)), identity),
None: () => false.AsTask())
select y
? x
: None;
public static CondAsync <A, B> Any <A, B>(this Cond <A, B> self, params Func <B, Task <bool> >[] predicates) =>
input =>
from x in self.ToAsync()(input)
from y in x.Match(
Some: b => Tasks.Exists(predicates.Map(p => p(b)), identity),
None: () => Task.FromResult(false))
select y
? x
: None;
public static CondAsync <A, D> SelectMany <A, B, C, D>(
this Cond <A, B> self,
Func <B, CondAsync <A, C> > bind,
Func <B, C, D> project) =>
input =>
from b in self.ToAsync()(input)
from c in b.Match(
Some: b1 => bind(b1)(input),
None: () => Option <C> .None.AsTask())
select(from x in b
from y in c
select project(x, y));
public static CondAsync <A, B> Where <A, B>(this Cond <A, B> self, Func <B, Task <bool> > pred) => input => from b in self.ToAsync()(input) from p in b.Map(pred).IfNone(false.AsTask()) select p ? b : None;
public static CondAsync <A, B> Then <A, B>(this Cond <A, A> self, Func <A, Task <B> > f) => self.ToAsync().Select(f);