Re: Recursive data-types

[Rikki Cattermole via Digitalmars-d-learn]

On 27/09/2014 11:26 p.m., ponce wrote:

I'm dabbling with Scheme interpreter and ultimately I would need to
declare the following types.

--------------

struct Function
{
     Environment env;
     Atom params;
     Atom body_;
}

// An atom is either a string, a double, a symbol, a function or a list
of atoms
alias Atom = Algebraic!(string, double, Symbol, Function, This[]);

--------------

These definitions can't work since Function and Atom need each other in
this recursive definition.

How to get out of this trap?
Do I have to drop Algebraic and go back to manual tagged unions?

Converting Function to a class. No where near ideal. But it'll work.