kyleheadley

trait Nat {}
struct Zero;
impl Nat for Zero {}
struct Succ<N>(N);
impl<N:Nat> Nat for Succ<N> {}

type One = Succ <Zero >;

trait AddOne : Nat { type Result:Nat; }
impl<N:Nat> AddOne for N { type Result = Succ<N>; }

kyleheadley

#![allow(unused)]

// Meta values and functions
// -------------------------

// Bool values
struct False;
struct True;

// Option values

kyleheadley

use std::ops::Deref;
use std::rc::Rc;
use std::sync::Arc;

trait PtrFunc<A> {type Ptr:Sized+Clone+Deref+From<A>;}

struct RcPtr;
impl<A> PtrFunc<A> for RcPtr {type Ptr = Rc<A>;}
struct ArcPtr;
impl<A> PtrFunc<A> for ArcPtr {type Ptr = Arc<A>;}

kyleheadley

/// Higher-order macro fold function for pre-parsing comma separated lists
///
/// The commas on KEYWORD lines can be changed to parse lists with any
/// separator. 

/// run a macro on a list of lists after splitting the input at commas
macro_rules! split_comma {
    // no defaults
    {$fun:ident <= $($item:tt)*} => {
        split_comma![$fun () () () <= $($item)*]

kyleheadley

//! Demo of static "inheritance"
//!
//! Use trait objects to get dynamic inheritance,
//! but casting to a subtype is not explored here

////////////////////////////////////////////////////////
// Define Base type, interface, and what is overloadable
////////////////////////////////////////////////////////

/// The main type that will be extended

kyleheadley

#![allow(unused)]
//#![feature(optin_builtin_traits)]

// Booleans
struct True;
struct False;
trait BoolOr<B> {type BoolOr;}
impl<B> BoolOr<B> for True {type BoolOr=True;}
impl BoolOr<True> for False {type BoolOr=True;}
impl BoolOr<False> for False {type BoolOr=False;}