| // Copyright 2012-2015 The Rust Project Developers. See the COPYRIGHT |
| // file at the top-level directory of this distribution and at |
| // http://rust-lang.org/COPYRIGHT. |
| // |
| // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or |
| // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license |
| // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your |
| // option. This file may not be copied, modified, or distributed |
| // except according to those terms. |
| |
| enum Nil {NilValue} |
| struct Cons<T> {head:isize, tail:T} |
| trait Dot {fn dot(&self, other:Self) -> isize;} |
| impl Dot for Nil { |
| fn dot(&self, _:Nil) -> isize {0} |
| } |
| impl<T:Dot> Dot for Cons<T> { |
| fn dot(&self, other:Cons<T>) -> isize { |
| self.head * other.head + self.tail.dot(other.tail) |
| } |
| } |
| fn test<T:Dot> (n:isize, i:isize, first:T, second:T) ->isize { //~ ERROR recursion limit |
| match n { 0 => {first.dot(second)} |
| // FIXME(#4287) Error message should be here. It should be |
| // a type error to instantiate `test` at a type other than T. |
| _ => {test (n-1, i+1, Cons {head:2*i+1, tail:first}, Cons{head:i*i, tail:second})} |
| } |
| } |
| pub fn main() { |
| let n = test(1, 0, Nil::NilValue, Nil::NilValue); |
| println!("{}", n); |
| } |
