auto merge of #9583 : blake2-ppc/rust/connect-vec, r=huonw

std::vec: Sane implementations for connect_vec and concat_vec

Avoid unnecessary copying of subvectors, and calculate the needed space
beforehand. These implementations are simple but better than the
previous.

Also only implement it once, for all `Vector<T>` using:

    impl<'self, T: Clone, V: Vector<T>> VectorVector<T> for &'self [V]

Closes #9581
This commit is contained in:
bors 2013-09-28 07:31:02 -07:00
commit c635fba748
3 changed files with 45 additions and 54 deletions

View File

@ -773,12 +773,12 @@ pub fn specialize(cx: &MatchCheckCtxt,
let num_elements = before.len() + after.len();
if num_elements < arity && slice.is_some() {
Some(vec::append(
vec::concat(&[
[
before,
vec::from_elem(
arity - num_elements, wild()),
after
]),
].concat_vec(),
r.tail()
))
} else if num_elements == arity {

View File

@ -173,12 +173,11 @@ impl Clean<Item> for doctree::Module {
visibility: self.vis.clean(),
id: self.id,
inner: ModuleItem(Module {
items: std::vec::concat(&[self.structs.clean(),
self.enums.clean(), self.fns.clean(),
std::vec::concat(self.foreigns.clean()),
self.mods.clean(), self.typedefs.clean(),
self.statics.clean(), self.traits.clean(),
self.impls.clean(), self.view_items.clean()])
items: [self.structs.clean(), self.enums.clean(),
self.fns.clean(), self.foreigns.clean().concat_vec(),
self.mods.clean(), self.typedefs.clean(),
self.statics.clean(), self.traits.clean(),
self.impls.clean(), self.view_items.clean()].concat_vec()
})
}
}

View File

@ -340,59 +340,36 @@ pub fn flat_map<T, U>(v: &[T], f: &fn(t: &T) -> ~[U]) -> ~[U] {
result
}
/// Flattens a vector of vectors of T into a single vector of T.
pub fn concat<T:Clone>(v: &[~[T]]) -> ~[T] { v.concat_vec() }
/// Concatenate a vector of vectors, placing a given separator between each
pub fn connect<T:Clone>(v: &[~[T]], sep: &T) -> ~[T] { v.connect_vec(sep) }
/// Flattens a vector of vectors of T into a single vector of T.
pub fn concat_slices<T:Clone>(v: &[&[T]]) -> ~[T] { v.concat_vec() }
/// Concatenate a vector of vectors, placing a given separator between each
pub fn connect_slices<T:Clone>(v: &[&[T]], sep: &T) -> ~[T] { v.connect_vec(sep) }
#[allow(missing_doc)]
pub trait VectorVector<T> {
// FIXME #5898: calling these .concat and .connect conflicts with
// StrVector::con{cat,nect}, since they have generic contents.
/// Flattens a vector of vectors of T into a single vector of T.
fn concat_vec(&self) -> ~[T];
/// Concatenate a vector of vectors, placing a given separator between each.
fn connect_vec(&self, sep: &T) -> ~[T];
}
impl<'self, T:Clone> VectorVector<T> for &'self [~[T]] {
/// Flattens a vector of slices of T into a single vector of T.
impl<'self, T: Clone, V: Vector<T>> VectorVector<T> for &'self [V] {
fn concat_vec(&self) -> ~[T] {
self.flat_map(|inner| (*inner).clone())
}
/// Concatenate a vector of vectors, placing a given separator between each.
fn connect_vec(&self, sep: &T) -> ~[T] {
let mut r = ~[];
let mut first = true;
for inner in self.iter() {
if first { first = false; } else { r.push((*sep).clone()); }
r.push_all((*inner).clone());
let size = self.iter().fold(0u, |acc, v| acc + v.as_slice().len());
let mut result = with_capacity(size);
for v in self.iter() {
result.push_all(v.as_slice())
}
r
}
}
impl<'self,T:Clone> VectorVector<T> for &'self [&'self [T]] {
/// Flattens a vector of slices of T into a single vector of T.
fn concat_vec(&self) -> ~[T] {
self.flat_map(|&inner| inner.to_owned())
result
}
/// Concatenate a vector of slices, placing a given separator between each.
fn connect_vec(&self, sep: &T) -> ~[T] {
let mut r = ~[];
let size = self.iter().fold(0u, |acc, v| acc + v.as_slice().len());
let mut result = with_capacity(size + self.len());
let mut first = true;
for &inner in self.iter() {
if first { first = false; } else { r.push((*sep).clone()); }
r.push_all(inner);
for v in self.iter() {
if first { first = false } else { result.push(sep.clone()) }
result.push_all(v.as_slice())
}
r
result
}
}
@ -3109,24 +3086,21 @@ mod tests {
#[test]
fn test_concat() {
assert_eq!(concat([~[1], ~[2,3]]), ~[1, 2, 3]);
let v: [~[int], ..0] = [];
assert_eq!(v.concat_vec(), ~[]);
assert_eq!([~[1], ~[2,3]].concat_vec(), ~[1, 2, 3]);
assert_eq!(concat_slices([&[1], &[2,3]]), ~[1, 2, 3]);
assert_eq!([&[1], &[2,3]].concat_vec(), ~[1, 2, 3]);
}
#[test]
fn test_connect() {
assert_eq!(connect([], &0), ~[]);
assert_eq!(connect([~[1], ~[2, 3]], &0), ~[1, 0, 2, 3]);
assert_eq!(connect([~[1], ~[2], ~[3]], &0), ~[1, 0, 2, 0, 3]);
let v: [~[int], ..0] = [];
assert_eq!(v.connect_vec(&0), ~[]);
assert_eq!([~[1], ~[2, 3]].connect_vec(&0), ~[1, 0, 2, 3]);
assert_eq!([~[1], ~[2], ~[3]].connect_vec(&0), ~[1, 0, 2, 0, 3]);
assert_eq!(connect_slices([], &0), ~[]);
assert_eq!(connect_slices([&[1], &[2, 3]], &0), ~[1, 0, 2, 3]);
assert_eq!(connect_slices([&[1], &[2], &[3]], &0), ~[1, 0, 2, 0, 3]);
assert_eq!(v.connect_vec(&0), ~[]);
assert_eq!([&[1], &[2, 3]].connect_vec(&0), ~[1, 0, 2, 3]);
assert_eq!([&[1], &[2], &[3]].connect_vec(&0), ~[1, 0, 2, 0, 3]);
}
@ -3758,7 +3732,9 @@ mod tests {
#[cfg(test)]
mod bench {
use extra::test::BenchHarness;
use iter::range;
use vec;
use vec::VectorVector;
use option::*;
#[bench]
@ -3798,4 +3774,20 @@ mod bench {
xs + ys;
}
}
#[bench]
fn concat(bh: &mut BenchHarness) {
let xss: &[~[uint]] = vec::from_fn(100, |i| range(0, i).collect());
do bh.iter {
xss.concat_vec();
}
}
#[bench]
fn connect(bh: &mut BenchHarness) {
let xss: &[~[uint]] = vec::from_fn(100, |i| range(0, i).collect());
do bh.iter {
xss.connect_vec(&0);
}
}
}