22 lines
464 B
Rust
22 lines
464 B
Rust
// xfail-fast
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#[legacy_modes];
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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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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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