55 lines
1.1 KiB
Rust
55 lines
1.1 KiB
Rust
import a::*;
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trait plus {
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fn plus() -> int;
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}
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mod a {
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impl uint: plus { fn plus() -> int { self as int + 20 } }
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}
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mod b {
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impl ~str: plus { fn plus() -> int { 200 } }
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}
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trait uint_utils {
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fn str() -> ~str;
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fn multi(f: fn(uint));
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}
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impl uint: uint_utils {
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fn str() -> ~str { uint::str(self) }
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fn multi(f: fn(uint)) {
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let mut c = 0u;
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while c < self { f(c); c += 1u; }
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}
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}
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trait vec_utils<T> {
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fn length_() -> uint;
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fn iter_(f: fn(T));
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fn map_<U>(f: fn(T) -> U) -> ~[U];
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}
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impl<T> ~[T]: vec_utils<T> {
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fn length_() -> uint { vec::len(self) }
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fn iter_(f: fn(T)) { for self.each |x| { f(x); } }
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fn map_<U>(f: fn(T) -> U) -> ~[U] {
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let mut r = ~[];
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for self.each |elt| { r += ~[f(elt)]; }
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r
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}
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}
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fn main() {
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assert 10u.plus() == 30;
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assert (~"hi").plus() == 200;
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assert (~[1]).length_().str() == ~"1";
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assert (~[3, 4]).map_(|a| a + 4 )[0] == 7;
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assert (~[3, 4]).map_::<uint>(|a| a as uint + 4u )[0] == 7u;
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let mut x = 0u;
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10u.multi(|_n| x += 2u );
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assert x == 20u;
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}
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