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authorTill Höppner2016-03-09 21:27:17 +0100
committerTill Höppner2016-03-09 21:27:17 +0100
commitc7f8c7e985173e504191b95286f53e0927db2d78 (patch)
tree360f8a90b79fa32e363c7f9e3a78d62027ad8d17 /src/lazy.rs
parentb402a084e7d7bbeb59d58e400fadb7bbdbf0e699 (diff)
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[ci skip] Remove accidentally commited scratch files
Diffstat (limited to 'src/lazy.rs')
-rw-r--r--src/lazy.rs74
1 files changed, 0 insertions, 74 deletions
diff --git a/src/lazy.rs b/src/lazy.rs
deleted file mode 100644
index b4f801b..0000000
--- a/src/lazy.rs
+++ /dev/null
@@ -1,74 +0,0 @@
-#![macro_escape]
-
-use std::ptr;
-use std::cell::UnsafeCell;
-use std::ops::Deref;
-use std::boxed::FnBox;
-
-pub enum State<V> {
- Evaluated(V),
- Evaluating,
- Unevaluated(Box<FnBox() -> V>)
-}
-
-pub struct Lazy<V> {
- state: UnsafeCell<State<V>>,
-}
-
-impl<V> Lazy<V> {
- pub fn new(f: Box<FnBox() -> V>) -> Lazy<V> {
- Lazy { state: UnsafeCell::new(State::Unevaluated(f)) }
- }
-
- pub fn ready(v: V) -> Lazy<V> {
- Lazy { state: UnsafeCell::new(State::Evaluated(v)) }
- }
-
- pub fn force(&mut self) {
- self.value();
- }
-
- pub fn unwrap(self) -> V {
- unsafe {
- match self.state.into_inner() {
- State::Unevaluated(f) => f(),
- State::Evaluating => panic!("Illegal state, can't call unwrap during evaluation"),
- State::Evaluated(v) => v
- }
- }
- }
-
- pub fn value(&self) -> &V {
- unsafe {
- let state = self.state.get();
- match *state {
- State::Evaluated(ref v) => v,
- State::Evaluating => panic!("Illegal state, can't call value during evaluation"),
- State::Unevaluated(_) => {
- if let State::Unevaluated(f) = ptr::replace(state, State::Evaluating) {
- ptr::replace(state, State::Evaluated(f()));
- }
- if let State::Evaluated(ref v) = *state { return v }
- unreachable!()
- }
- }
- }
- }
-}
-
-impl<V> Deref for Lazy<V> {
- type Target = V;
- fn deref(&self) -> &V { self.value() }
-}
-
-#[macro_export]
-macro_rules! lazy {
- (@as_expr $val: expr) => { $val };
- ($($val: tt)*) => { Lazy::new(Box::new(move || lazy![@as_expr { $($val)* }])) };
-}
-
-#[macro_export]
-macro_rules! eager {
- (@as_expr $val: expr) => { $val };
- ($($val: tt)*) => { Lazy::<_>::ready(eager![@as_expr { $($val)* }]) };
-}