public static State <S, Reader <E, V> > SelectMany <S, E, T, U, V>(
this State <S, T> self,
Func <T, Reader <E, U> > bind,
Func <T, U, V> project
)
{
if (bind == null)
{
throw new ArgumentNullException("bind");
}
if (project == null)
{
throw new ArgumentNullException("project");
}
return((S s) =>
{
var resT = self(s);
if (resT.IsBottom)
{
return StateResult.Bottom <S, Reader <E, V> >(s);
}
return StateResult.Return <S, Reader <E, V> >(resT.State, envInner =>
{
var resU = bind(resT.Value)(envInner);
if (resU.IsBottom)
{
return new ReaderResult <V>(default(V), true);
}
return ReaderResult.Return(project(resT.Value, resU.Value));
});
});
}
public static Writer <Out, Reader <E, V> > SelectMany <Out, E, T, U, V>(
this Writer <Out, T> self,
Func <T, Reader <E, U> > bind,
Func <T, U, V> project
)
{
if (bind == null)
{
throw new ArgumentNullException("bind");
}
if (project == null)
{
throw new ArgumentNullException("project");
}
return(() =>
{
var resT = self();
if (resT.IsBottom)
{
return WriterResult.Bottom <Out, Reader <E, V> >(resT.Output);
}
return WriterResult.Return <Out, Reader <E, V> >(env =>
{
var resU = bind(resT.Value)(env);
if (resU.IsBottom)
{
return ReaderResult.Bottom <V>();
}
return ReaderResult.Return(project(resT.Value, resU.Value));
}, resT.Output);
});
}
public static Reader <Env, A> tryread <Env, A>(Reader <Env, A> m) =>
state =>
{
try
{
return(m(state));
}
catch (Exception e)
{
return(ReaderResult <A> .New(Common.Error.New(e)));
}
};
private static ReaderResult <Unit> bmap <T>(ReaderResult <T> r, Action <T> f)
{
if (r.IsBottom)
{
return(Bottom <Unit>());
}
else
{
f(r.Value);
return(Return(unit));
}
}
internal static Reader <Env, List <B> > TraverseFast <Env, A, B>(this IEnumerable <Reader <Env, A> > ma, Func <A, B> f) => env =>
{
var values = new List <B>();
foreach (var item in ma)
{
var resA = item(env);
if (resA.IsFaulted)
{
return(ReaderResult <List <B> > .New(resA.ErrorInt));
}
values.Add(f(resA.Value));
}
return(ReaderResult <List <B> > .New(values));
};
internal static Reader <Env, List <A> > SequenceFast <Env, A>(this IEnumerable <Reader <Env, A> > ta) => env =>
{
var values = new List <A>();
foreach (var item in ta)
{
var resA = item(env);
if (resA.IsFaulted)
{
return(ReaderResult <List <A> > .New(resA.ErrorInt));
}
values.Add(resA.Value);
}
return(ReaderResult <List <A> > .New(values));
};
public static Reader <Env, A> ReaderFail <Env, A>(Exception exception) => env => ReaderResult <A> .New(Common.Error.New(exception));
public static Reader <Env, A> ReaderFail <Env, A>(int code, string error) => env => ReaderResult <A> .New(Common.Error.New(code, error));
private static ReaderResult <R> bmap <T, R>(ReaderResult <T> r, Func <T, R> f) =>
r.IsBottom
? Bottom <R>()
: Return(f(r.Value));
private static ReaderResult <T> Bottom <T>() => ReaderResult.Bottom <T>();
private static ReaderResult <T> Return <T>(T value) => ReaderResult.Return(value);
