[Feature request] Enum.lookup(value) support for cenums

[TechnicalFowl]

It would be appreciated to be able to call lookup on a const enum type similar to how it used to work with inline associated members.

Example usage:

import std;

enum Foo : const
{
	VAL1 = 1,
	VAL2 = 2,
	VAL42 = 42,
}

fn void main()
{
	Foo f = Foo.lookup(42);
	io::printfn("Value: %s", f);
}

[lerno]

Hmm.. what would be the use of this? Given that this works it will still just print 42.

[lerno]

Maybe you're thinking of a name lookup? In that case it would be more like:

fn void main()
{
  Foo f = (Foo)42;
  String name = f.lookup_name();  
  io::printfn("Value: %s", name);
}

[TechnicalFowl]

Yeah sorry, some way of going back to the name of the enum entry, Foo.names[f.ordinal] would also work I suppose if that was supported again. I realize now that the way I wrote the original code was a little bit dumb :)

This was my temp solution

fn String Foo.get_name(&self)
{
	for (int i = 0; i < Foo.values.len; ++i)
	{
		if (*self == Foo.values[i])
		{
			return Foo.names[i];
		}
	}
	return "Unknown";
}

[lerno]

That one seems correct, although you can write it more succinctly as:

fn String Foo.get_name(&self)
{
	foreach (i, &val : Foo.values)
	{
		if (*self == *val)
		{
			return Foo.names[i];
		}
	}
	return "Unknown";
}

But you can also create a compile time foreach, like:

fn String Foo.get_name(&self)
{
  $foreach $i, $foo : Foo.values:
  if (*self == $foo) return Foo.names[$i];
  $endforach
  return "Unknown";
}

[lerno]

Is this feature needed still you think?