public static void LinqFuncEitherTest()
{
var cxt = new EitherCxt <string>();
var init = 5;
var computation =
from x in MaybeT.Lift(cxt.FromRight(45))
from y in MaybeT.Lift(cxt.FromRight(90))
from _ in MaybeT.HoistEither(cxt, Maybe.JustIf(init > 0, () => new Unit()))
from z in MaybeT.Lift(cxt.FromRight(100))
select x + y + z;
var value = computation.Run;
Assert.True(value.IsRight);
Assert.True(value.Right().HasValue);
Assert.Equal(45 + 90 + 100, value.Right().Value());
init = 0;
computation =
from x in MaybeT.Lift(cxt.FromRight(45))
from y in MaybeT.Lift(cxt.FromRight(90))
from _ in MaybeT.HoistEither(cxt, Maybe.JustIf(init > 0, () => new Unit()))
from z in MaybeT.Lift(cxt.FromRight(100))
select x + y + z;
value = computation.Run;
Assert.False(value.IsLeft);
}
HoistEither <TLeft, TValue>(
EitherCxt <TLeft> _cxt,
Maybe <TValue> value)
{
var m = new MaybeT <Either <TLeft, TValue>, Either <TLeft, Maybe <TValue> >, Maybe <TValue>, TValue>();
return((MaybeT <Either <TLeft, TValue>, Either <TLeft, Maybe <TValue> >, Maybe <TValue>, TValue>)m.Hoist(value));
}
