internal compiler error

[potan]

error: internal compiler error: type_of with ty_param
note: the compiler hit an unexpected failure path. this is a bug.
note: we would appreciate a bug report: http://doc.rust-lang.org/complement-bugreport.html
note: run with `RUST_BACKTRACE=1` for a backtrace
task 'rustc' failed at 'Box<Any>', /home/pm/lang/rust/rust/src/libsyntax/diagnostic.rs:169

stack backtrace:
   1:     0x7fdc7b12c500 - rt::backtrace::imp::write::h1477ac29053ece3cgDq
   2:     0x7fdc7b12f630 - failure::on_fail::h090bf222fe08db7cDYq
   3:     0x7fdc7b8f6430 - unwind::begin_unwind_inner::h51916ee1d5d0deddGxd
   4:     0x7fdc77529790 - unwind::begin_unwind::h15240260624484748152
   5:     0x7fdc77529e70 - diagnostic::Handler::bug::had6fd9d040101c34hRF
   6:     0x7fdc7bcda490 - driver::session::Session::bug::h85ae544149280a1fTey
   7:     0x7fdc7c0b80e0 - middle::trans::type_of::type_of::h3c358519e57ad9e6Zxa
   8:     0x7fdc7c0b80e0 - middle::trans::type_of::type_of::h3c358519e57ad9e6Zxa
   9:     0x7fdc7c0b80e0 - middle::trans::type_of::type_of::h3c358519e57ad9e6Zxa
  10:     0x7fdc7c1d9270 - middle::trans::adt::struct_llfields::h6d3c4aa8a91bfda3sIu
  11:     0x7fdc7c13ec20 - middle::trans::adt::finish_type_of::h54eeac837f85766amwu
  12:     0x7fdc7c0b80e0 - middle::trans::type_of::type_of::h3c358519e57ad9e6Zxa
  13:     0x7fdc7c0b80e0 - middle::trans::type_of::type_of::h3c358519e57ad9e6Zxa
  14:     0x7fdc7c0fa410 - middle::trans::expr::trans_uniq_expr::h5a4901312595da40iC5
  15:     0x7fdc7c0face0 - middle::trans::expr::trans_unary::h7f46b3d2ee23e0f1oy5
  16:     0x7fdc7c0f0000 - middle::trans::expr::trans_unadjusted::he0f7295d106fefd2Zd4
  17:     0x7fdc7c0b3810 - middle::trans::expr::trans::haaafc6b790c7b639Vw3
  18:     0x7fdc7c0b22c0 - middle::trans::expr::trans_into::h3d5706a30846aafa1s3
  19:     0x7fdc7c0b26e0 - middle::trans::controlflow::trans_block::hd5280d031efda9d6lGZ
  20:     0x7fdc7c162fe0 - middle::trans::base::trans_closure::h0a7f4de06bee1c8cXBf
  21:     0x7fdc7c0a41f0 - middle::trans::base::trans_fn::h8f8a2c035208e8d7lNf
  22:     0x7fdc7c0a48e0 - middle::trans::monomorphize::monomorphic_fn::h2dc0c402c9883ce927Y
  23:     0x7fdc7c0dc660 - middle::trans::callee::trans_fn_ref_with_substs::hdd194b502b4a58441m2
  24:     0x7fdc7c0d9c80 - middle::trans::callee::trans_fn_ref::h4330edb19ab1b6e6zb2
  25:     0x7fdc7c0e2570 - middle::trans::callee::trans_call::closure.124125
  26:     0x7fdc7c0ba020 - middle::trans::callee::trans_call_inner::hcbca3b6787659c03JI2
  27:     0x7fdc7c0e22c0 - middle::trans::callee::trans_call::h9fcac721e6cb55314C2
  28:     0x7fdc7c0f13c0 - middle::trans::expr::trans_rvalue_dps_unadjusted::hd9a2a83d30d7aaeftR4
  29:     0x7fdc7c0b22c0 - middle::trans::expr::trans_into::h3d5706a30846aafa1s3
  30:     0x7fdc7c191c90 - middle::trans::_match::store_local::closure.128240
  31:     0x7fdc7c191a80 - middle::trans::_match::mk_binding_alloca::h482564913738985314
  32:     0x7fdc7c1597e0 - middle::trans::_match::store_local::h3d0fc4ae7771500aNZi
  33:     0x7fdc7c0b18a0 - middle::trans::base::init_local::h2cb16046bc383b89xKe
  34:     0x7fdc7c0b0c60 - middle::trans::controlflow::trans_stmt::h4f1b84665f48152afBZ
  35:     0x7fdc7c0b26e0 - middle::trans::controlflow::trans_block::hd5280d031efda9d6lGZ
  36:     0x7fdc7c162fe0 - middle::trans::base::trans_closure::h0a7f4de06bee1c8cXBf
  37:     0x7fdc7c0a41f0 - middle::trans::base::trans_fn::h8f8a2c035208e8d7lNf
  38:     0x7fdc7c0a1850 - middle::trans::base::trans_item::h5de357321a9ed4f6E6f
  39:     0x7fdc7c16e5a0 - middle::trans::base::trans_crate::hc46c87ff47e81464a5g
  40:     0x7fdc7c5bfb70 - driver::driver::phase_4_translate_to_llvm::h045fe4f7e55962abvFx
  41:     0x7fdc7c5b5e70 - driver::driver::compile_input::hf1074c4e89201e93qcx
  42:     0x7fdc7c6412a0 - driver::run_compiler::h0ecb6658398d53f6J0A
  43:     0x7fdc7c641150 - driver::run::closure.147558
  44:     0x7fdc7bd09cd0 - task::TaskBuilder<S>::try_future::closure.101668
  45:     0x7fdc7bd09ab0 - task::TaskBuilder<S>::spawn_internal::closure.101639
  46:     0x7fdc7ceb1120 - task::spawn_opts::closure.8447
  47:     0x7fdc7b9503e0 - rust_try_inner
  48:     0x7fdc7b9503d0 - rust_try
  49:     0x7fdc7b8f3cf0 - unwind::try::h15600d03dfaaa405omd
  50:     0x7fdc7b8f3b70 - task::Task::run::h2760aad0762be53e2Bc
  51:     0x7fdc7ceb0e60 - task::spawn_opts::closure.8387
  52:     0x7fdc7b8f5440 - thread::thread_start::h7a688dc7bb49fbdedWc
  53:     0x7fdc7abf3ec0 - start_thread
  54:     0x7fdc7b5b99d9 - __clone
  55:                0x0 - <unknown>

while compile code:

#![feature(unboxed_closures, overloaded_calls, unboxed_closure_sugar)]

pub trait Seq<T> {
    fn pop(self) -> Result<(T, Self, Self), Self>;
}

impl<'a> Seq<char> for &'a str {
    fn pop(self) -> Result<(char, &'a str, &'a str), &'a str> {
        if self.is_empty() {
            Err(self)
        } else {
            Ok((self.char_at(0), self, self.slice_from(1)))
        }
    }
}

type ParseResult<S /*:Seq<C>*/,T> = Result<(T, S, S),S>;
type Parser<S /*:Seq<C>*/,T> = Box<|&: S| -> ParseResult<S /*:Seq<C>*/,T>>;

fn elem<T, S:Seq<T>, Res>(e:Box<|&: T| -> Option<Res>>) -> Parser<S, Res> {
  box |&: s:S| {
    match s.pop() {
      Err(b) => Err(b),
      Ok((c, b, n)) => match e.call((c,)) {
                         Some(r) => Ok((r, b, n)),
                         None => Err(b)
                       }
    }
  }
}

fn concat<C,S:Seq<C>,T1,T2>(p1: Parser<S, T1>, p2: Parser<S, T2>) -> Parser<S,(T1,T2)> {
  box |&: s:S| {
    match p1.call((s,)) {
       Err(b) => Err(b),
       Ok((r1, b, n1)) => {
         match p2.call((n1,)) {
            Err(_) => Err(b),
            Ok((r2, _, n2)) => Ok(((r1,r2), b, n2))
         }
       }
    }
  }
}

fn alter<C,S:Seq<C>,T>(p1: Parser<S, T>, p2: Parser<S, T>) -> Parser<S, T> {
  box |&: s:S| {
    match p1.call((s,)) {
       Err(b) => p2.call((b,)),
       r => r
    }
  }
}

fn digit(r:&int) -> Box<|&: char| -> Option<int>> {
  box |&: c:char| {
   let i = match c {
             '0'...'9' => { c as int - '0' as int },
             'a'...'z' => { 10 + c as int - 'a' as int },
             'A'...'Z' => { 10 + c as int - 'A' as int },
             _ => *r
           };
   if i < *r {
    Some(i)
   } else {
    None
   }
  }
}

fn do_fold<S,T,R>(p:&Parser<S,T>, l:&Box<|&: T,R| -> R>, b:S, i:R, s:S) -> ParseResult<S,R> {
  match p.call((s,)) {
    Err(n) => Ok((i,b,n)),
    Ok((r,_,n)) => {
      let v = l.call((r,i));
      do_fold(p,l,b,v,n)
    }
  }
}

fn fold1<S,T,R:Clone>(p:Parser<S,T>, l: Box<|&: T,R| -> R>, i:R) -> Parser<S,R> {
  box |&: s:S| {
    match p.call((s,)) {
      Err(e) => Err(e),
      Ok((r,b,n)) => {
        let v = l.call((r,i.clone()));
        do_fold(&p,&l,b,v,n)
      }
    }
  }
}

fn main() {
    static RADIX:int = 13;
    let p1 = fold1(elem(digit(&RADIX)), box |&: c:int, v:int| -> int {v*RADIX+c}, 0i) ;
    let p2 = alter(elem(box |&: c:char| { if c == 'z' { Some('Z') } else { None } }),
                   elem(box |&: c:char| { if c == 'w' { Some('W') } else { None } })) ;
    println!("{}", concat(p1, p2).call(("1awert",)));
}

[bkoropoff]

The code is garbled, but the backtrace and error look related to #16791

[bkoropoff]

@potan, can you re-test on the latest master now that the fix for #16791 went in?

[potan]

Internal compiler error has fixed.
Now rustc outputs "error: cannot infer an appropriate lifetime due to conflicting requirements", but earlier this code worked :-).

[bkoropoff]

One problem is that unboxed closures now default to by-ref capture where previously it was by move. After sprinkling the move keyword around, there were a few legitimate lifetime errors and missing bounds. After fixing them up it builds and runs. This bug can be closed.

#![feature(unboxed_closures, overloaded_calls, unboxed_closure_sugar)]

pub trait Seq<T> {
    fn pop(self) -> Result<(T, Self, Self), Self>;
}

impl<'a> Seq<char> for &'a str {
    fn pop(self) -> Result<(char, &'a str, &'a str), &'a str> {
        if self.is_empty() {
            Err(self)
        } else {
            Ok((self.char_at(0), self, self.slice_from(1)))
        }
    }
}

type ParseResult<S,T> = Result<(T, S, S),S>;
type Parser<S,T> = Box<|&: S| -> ParseResult<S,T>>;

fn elem<T, S:Seq<T>, Res>(e:Box<|&: T| -> Option<Res>>) -> Parser<S, Res> {
  box move |&: s:S| {
    match s.pop() {
      Err(b) => Err(b),
      Ok((c, b, n)) => match e.call((c,)) {
        Some(r) => Ok((r, b, n)),
        None => Err(b)
      }
    }
  }
}

fn concat<C,S:Seq<C>,T1,T2>(p1: Parser<S, T1>, p2: Parser<S, T2>) -> Parser<S,(T1,T2)> {
  box move |&: s:S| {
    match p1.call((s,)) {
       Err(b) => Err(b),
       Ok((r1, b, n1)) => {
         match p2.call((n1,)) {
            Err(_) => Err(b),
            Ok((r2, _, n2)) => Ok(((r1,r2), b, n2))
         }
       }
    }
  }
}

fn alter<C,S:Seq<C>,T>(p1: Parser<S, T>, p2: Parser<S, T>) -> Parser<S, T> {
  box move |&: s:S| {
    match p1.call((s,)) {
       Err(b) => p2.call((b,)),
       r => r
    }
  }
}

fn digit(r:&int) -> Box<|&: char| -> Option<int>> {
  let r = *r;
  box move |&: c:char| {
   let i = match c {
     '0'...'9' => { c as int - '0' as int },
     'a'...'z' => { 10 + c as int - 'a' as int },
     'A'...'Z' => { 10 + c as int - 'A' as int },
     _ => r
   };
   if i < r {
    Some(i)
   } else {
    None
   }
  }
}

fn do_fold<S,T,R>(p:&Parser<S,T>, l:&Box<|&: T,R| -> R>, b:S, i:R, s:S) -> ParseResult<S,R> {
  match p.call((s,)) {
    Err(n) => Ok((i,b,n)),
    Ok((r,_,n)) => {
      let v = l.call((r,i));
      do_fold(p,l,b,v,n)
    }
  }
}

fn fold1<S,T,R:Clone+'static>(p:Parser<S,T>, l: Box<|&: T,R| -> R>, i:R) -> Parser<S,R> {
  box move |&: s:S| {
    match p.call((s,)) {
      Err(e) => Err(e),
      Ok((r,b,n)) => {
        let v = l.call((r,i.clone()));
        do_fold(&p,&l,b,v,n)
      }
    }
  }
}

fn main() {
    static RADIX:int = 13;
    let p1 = fold1(elem(digit(&RADIX)), box |&: c:int, v:int| -> int {v*RADIX+c}, 0i) ;
    let p2 = alter(elem(box |&: c:char| { if c == 'z' { Some('Z') } else { None } }),
                   elem(box |&: c:char| { if c == 'w' { Some('W') } else { None } })) ;
    println!("{}", concat(p1, p2).call(("1awert",)));
}

[nodakai]

@aturon Can you check the status of this issue? Seems like you can close this

[nikomatsakis]

Going to close this on basis of @bkoropoff's comments. Re-open if you think there is still a problem.