Closed
Description
Will minify later
pub mod ltseal {
use std::marker::PhantomData;
#[derive(Copy)]
pub struct ContraLifetimeCell<'a, T>(T, PhantomData<*mut FnOnce(&'a ())>);
#[derive(Copy)]
pub struct ContraLifetimeSeal<'a>(PhantomData<*mut FnOnce(&'a ())>);
impl<'s> ContraLifetimeSeal<'s> {
pub fn seal<'a, T>(&'a self, t: T) -> ContraLifetimeCell<'s, T> {
ContraLifetimeCell(t, PhantomData)
}
pub fn unseal<'a, T>(&'a self, c: ContraLifetimeCell<'s, T>) -> T {
c.0
}
pub fn ref_unseal<'a, 'b, T>(&'a self,
c: &'b ContraLifetimeCell<'s, T>)
-> &'b T {
&c.0
}
pub fn with_seal<T, F: for<'a> FnOnce(ContraLifetimeSeal<'a>) -> T>
(f: F) -> T {
f(ContraLifetimeSeal(PhantomData))
}
}
}
pub mod deep {
/* language with only let, variables, addition as PoC */
use ltseal::ContraLifetimeCell as CLC;
pub enum Op {
Add,
}
pub enum Expr<'var, VAR> {
Lit(u32),
Op(Op, Box<Expr<'var, VAR>>, Box<Expr<'var, VAR>>),
Var(CLC<'var, VAR>),
Let(Box<Expr<'var, VAR>>,
Box<for<'v: 'var> Fn(Expr<'v, VAR>) -> Expr<'v, VAR> + 'var>)
}
pub fn add<'var, VAR, E1: ExprLike<'var, VAR>,
E2: ExprLike<'var, VAR>>
(a: E1, b: E2) -> Expr<'var, VAR> {
Expr::Op(Op::Add, a.as_expr(), b.as_expr())
}
pub fn let_<'var, VAR, E: ExprLike<'var, VAR>,
F: for<'v: 'var>
Fn(Expr<'v, VAR>) -> Expr<'v, VAR>>
(a: E, b: F) -> Expr<'var, VAR> {
Expr::Let(a.as_expr(), Box::new(b))
}
pub trait ExprLike<'var, VAR> {
fn as_expr(self) -> Box<Expr<'var, VAR>>;
}
impl<'var, VAR> ExprLike<'var, VAR> for u32 {
fn as_expr(self) -> Box<Expr<'var, VAR>> { Box::new(Expr::Lit(self)) }
}
impl<'var, VAR> ExprLike<'var, VAR> for Expr<'var, VAR> {
fn as_expr(self) -> Box<Expr<'var, VAR>> { Box::new(self) }
}
}
pub use deep::Expr as E;
pub use deep as d;
fn main() {
//let x=5 in let y=3 in let x=x+y in x
let ex = d::let_(5, |x| {
d::let_(3, |y| {
d::let_(d::add(x, y), |x|x
)})
});
drop(ex);
}Errors:
rror: internal compiler error: unexpected panic
note: the compiler unexpectedly panicked. this is a bug.
note: we would appreciate a bug report: https://github.com/rust-lang/rust/blob/master/CONTRIBUTING.md#bug-reports
note: run with `RUST_BACKTRACE=1` for a backtrace
thread 'rustc' panicked at 'called `Option::unwrap()` on a `None` value', /home/rustbuild/src/rust-buildbot/slave/nightly-dist-rustc-linux/build/src/libcore/option.rs:362