31 lines
917 B
Rust
31 lines
917 B
Rust
// Copyright 2012 The Rust Project Developers. See the COPYRIGHT
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// file at the top-level directory of this distribution and at
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// http://rust-lang.org/COPYRIGHT.
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//
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// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
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// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
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// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
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// option. This file may not be copied, modified, or distributed
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// except according to those terms.
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// xfail-fast
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fn fix_help<A, B>(f: extern fn(@fn(A) -> B, A) -> B, x: A) -> B {
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return f( |a| fix_help(f, a), x);
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}
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fn fix<A, B>(f: extern fn(@fn(A) -> B, A) -> B) -> @fn(A) -> B {
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return |a| fix_help(f, a);
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}
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fn fact_(f: @fn(v: int) -> int, n: int) -> int {
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// fun fact 0 = 1
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return if n == 0 { 1 } else { n * f(n - 1) };
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}
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pub fn main() {
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let fact = fix(fact_);
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assert!((fact(5) == 120));
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assert!((fact(2) == 2));
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}
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