88 lines
1.4 KiB
Rust
88 lines
1.4 KiB
Rust
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/*!
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The Finally trait provides a method, `finally` on
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stack closures that emulates Java-style try/finally blocks.
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# Example
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~~~
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do || {
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...
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}.finally {
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alway_run_this();
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}
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~~~
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*/
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use ops::Drop;
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use task::{spawn, failing};
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pub trait Finally<T> {
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fn finally(&self, +dtor: &fn()) -> T;
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}
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impl<T> &fn() -> T: Finally<T> {
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// XXX: Should not require a mode here
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fn finally(&self, +dtor: &fn()) -> T {
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let _d = Finallyalizer {
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dtor: dtor
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};
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(*self)()
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}
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}
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struct Finallyalizer {
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dtor: &fn()
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}
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impl Finallyalizer: Drop {
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fn finalize(&self) {
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(self.dtor)();
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}
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}
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#[test]
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fn test_success() {
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let mut i = 0;
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do (|| {
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i = 10;
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}).finally {
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assert !failing();
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assert i == 10;
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i = 20;
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}
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assert i == 20;
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}
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#[test]
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#[ignore(cfg(windows))]
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#[should_fail]
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fn test_fail() {
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let mut i = 0;
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do (|| {
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i = 10;
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fail;
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}).finally {
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assert failing();
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assert i == 10;
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}
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}
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#[test]
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fn test_retval() {
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let i = do (fn&() -> int {
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10
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}).finally { };
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assert i == 10;
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}
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#[test]
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fn test_compact() {
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// XXX Should be able to use a fn item instead
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// of a closure for do_some_fallible_work,
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// but it's a type error.
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let do_some_fallible_work: &fn() = || { };
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fn but_always_run_this_function() { }
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do_some_fallible_work.finally(
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but_always_run_this_function);
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}
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