/// <summary>
/// Map both the input and output of a decoder to
/// produce a new decoder.
/// </summary>
public static Decoder <TRaw2, T2> Dimap <TRaw1, T1, TRaw2, T2>(
this Decoder <TRaw1, T1> decoder,
[NotNull] Func <TRaw2, TRaw1> f,
[NotNull] Func <T1, T2> g)
{
if (f == null)
{
throw new ArgumentNullException(nameof(f));
}
if (g == null)
{
throw new ArgumentNullException(nameof(g));
}
return(new Decoder <TRaw2, T2>((id, x) => decoder.Run(id, f(x)).Map(g), decoder.Id));
}
/// <summary>
/// Return a new Decoder computed from the result of the first.
/// </summary>
public static Decoder <TRaw, T2> Bind <TRaw, T1, T2>(
this Decoder <TRaw, T1> decoder,
[NotNull] Func <T1, Decoder <TRaw, T2> > f)
{
if (f == null)
{
throw new ArgumentNullException(nameof(f));
}
return(new Decoder <TRaw, T2>(
(id, x) =>
from result1 in decoder.Run(id, x)
from result2 in f(result1).Run(id, x)
select result2,
decoder.Id));
}
/// <summary>
/// Create a Decoder that will select the first succesful result, or
/// the last failure.
/// </summary>
public static Decoder <TRaw, T> Or <TRaw, T>(
this Decoder <TRaw, T> decoder1,
Decoder <TRaw, T> decoder2)
{
return(new Decoder <TRaw, T>((id, x) => decoder1.Run(id, x) || decoder2.Run(id, x)));
}
