rust/src/libsyntax/owned_slice.rs
Alex Crichton 0cb7a4062a serialize: Use assoc types + less old_orphan_check
This commit moves the libserialize crate (and will force the hand of the
rustc-serialize crate) to not require the `old_orphan_check` feature gate as
well as using associated types wherever possible. Concretely, the following
changes were made:

* The error type of `Encoder` and `Decoder` is now an associated type, meaning
  that these traits have no type parameters.

* The `Encoder` and `Decoder` type parameters on the `Encodable` and `Decodable`
  traits have moved to the corresponding method of the trait. This movement
  alleviates the dependency on `old_orphan_check` but implies that
  implementations can no longer be specialized for the type of encoder/decoder
  being implemented.

Due to the trait definitions changing, this is a:

[breaking-change]
2015-01-04 22:59:26 -08:00

118 lines
3.0 KiB
Rust

// Copyright 2014 The Rust Project Developers. See the COPYRIGHT
// file at the top-level directory of this distribution and at
// http://rust-lang.org/COPYRIGHT.
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.
use std::default::Default;
use std::fmt;
use std::iter::FromIterator;
use std::ops::Deref;
use std::vec;
use serialize::{Encodable, Decodable, Encoder, Decoder};
/// A non-growable owned slice. This is a separate type to allow the
/// representation to change.
#[derive(Hash, PartialEq, Eq, PartialOrd, Ord)]
pub struct OwnedSlice<T> {
data: Box<[T]>
}
impl<T:fmt::Show> fmt::Show for OwnedSlice<T> {
fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
self.data.fmt(fmt)
}
}
impl<T> OwnedSlice<T> {
pub fn empty() -> OwnedSlice<T> {
OwnedSlice { data: box [] }
}
#[inline(never)]
pub fn from_vec(v: Vec<T>) -> OwnedSlice<T> {
OwnedSlice { data: v.into_boxed_slice() }
}
#[inline(never)]
pub fn into_vec(self) -> Vec<T> {
self.data.into_vec()
}
pub fn as_slice<'a>(&'a self) -> &'a [T] {
&*self.data
}
pub fn move_iter(self) -> vec::IntoIter<T> {
self.into_vec().into_iter()
}
pub fn map<U, F: FnMut(&T) -> U>(&self, f: F) -> OwnedSlice<U> {
self.iter().map(f).collect()
}
}
impl<T> Deref for OwnedSlice<T> {
type Target = [T];
fn deref(&self) -> &[T] {
self.as_slice()
}
}
impl<T> Default for OwnedSlice<T> {
fn default() -> OwnedSlice<T> {
OwnedSlice::empty()
}
}
impl<T: Clone> Clone for OwnedSlice<T> {
fn clone(&self) -> OwnedSlice<T> {
OwnedSlice::from_vec(self.as_slice().to_vec())
}
}
impl<T> FromIterator<T> for OwnedSlice<T> {
fn from_iter<I: Iterator<Item=T>>(iter: I) -> OwnedSlice<T> {
OwnedSlice::from_vec(iter.collect())
}
}
#[cfg(stage0)]
impl<S: Encoder<E>, T: Encodable<S, E>, E> Encodable<S, E> for OwnedSlice<T> {
fn encode(&self, s: &mut S) -> Result<(), E> {
self.as_slice().encode(s)
}
}
#[cfg(not(stage0))]
impl<T: Encodable> Encodable for OwnedSlice<T> {
fn encode<S: Encoder>(&self, s: &mut S) -> Result<(), S::Error> {
self.as_slice().encode(s)
}
}
#[cfg(stage0)]
impl<D: Decoder<E>, T: Decodable<D, E>, E> Decodable<D, E> for OwnedSlice<T> {
fn decode(d: &mut D) -> Result<OwnedSlice<T>, E> {
Ok(OwnedSlice::from_vec(match Decodable::decode(d) {
Ok(t) => t,
Err(e) => return Err(e)
}))
}
}
#[cfg(not(stage0))]
impl<T: Decodable> Decodable for OwnedSlice<T> {
fn decode<D: Decoder>(d: &mut D) -> Result<OwnedSlice<T>, D::Error> {
Ok(OwnedSlice::from_vec(match Decodable::decode(d) {
Ok(t) => t,
Err(e) => return Err(e)
}))
}
}