public static void LinqReaderTest()
{
var cxt = new ReaderCxt <Dictionary <int, int> >();
var computation =
from x in MaybeT.Lift(cxt.Get())
from y in MaybeT.Lift(cxt.With(env => env[4]))
from z in MaybeT.Lift(cxt.Local(dict => {
var d2 = new Dictionary <int, int>(dict)
{
[99] = 150
}; return(d2);
}, from u in cxt.Get() select u[99]))
from _ in MaybeT.HoistReader(cxt, Maybe.JustIf(x.ContainsKey(120), () => new Unit()))
select x[1] + y + z;
var value = computation.Run.Run(new Dictionary <int, int> {
{ 1, 2 }, { 4, 8 }, { 16, 32 }, { 120, 0 }
});
Assert.True(value.HasValue);
Assert.Equal(2 + 8 + 150, value.Value());
value = computation.Run.Run(new Dictionary <int, int> {
{ 1, 2 }, { 4, 8 }, { 16, 32 }
});
Assert.False(value.HasValue);
}
HoistReader <TEnvironment, TValue>(
ReaderCxt <TEnvironment> _cxt,
Maybe <TValue> value)
{
var m = new MaybeT <Reader <TEnvironment, TValue>, Reader <TEnvironment, Maybe <TValue> >, Maybe <TValue>, TValue>();
return((MaybeT <Reader <TEnvironment, TValue>, Reader <TEnvironment, Maybe <TValue> >, Maybe <TValue>, TValue>)m.Hoist(value));
}