rust/src/libstd/at_vec.rs

337 lines
9.7 KiB
Rust

// Copyright 2012 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.
//! Managed vectors
use cast::transmute;
use container::Container;
use iterator::IteratorUtil;
use kinds::Copy;
use option::Option;
use sys;
use uint;
use vec::{ImmutableVector, OwnedVector};
/// Code for dealing with @-vectors. This is pretty incomplete, and
/// contains a bunch of duplication from the code for ~-vectors.
pub mod rustrt {
use libc;
use vec;
#[cfg(stage0)]
use intrinsic::{TyDesc};
#[cfg(not(stage0))]
use unstable::intrinsics::{TyDesc};
#[abi = "cdecl"]
#[link_name = "rustrt"]
pub extern {
pub unsafe fn vec_reserve_shared_actual(t: *TyDesc,
v: **vec::raw::VecRepr,
n: libc::size_t);
}
}
/// Returns the number of elements the vector can hold without reallocating
#[inline]
pub fn capacity<T>(v: @[T]) -> uint {
unsafe {
let repr: **raw::VecRepr = transmute(&v);
(**repr).unboxed.alloc / sys::size_of::<T>()
}
}
/**
* Builds a vector by calling a provided function with an argument
* function that pushes an element to the back of a vector.
* This version takes an initial size for the vector.
*
* # Arguments
*
* * size - An initial size of the vector to reserve
* * builder - A function that will construct the vector. It receives
* as an argument a function that will push an element
* onto the vector being constructed.
*/
#[inline]
pub fn build_sized<A>(size: uint, builder: &fn(push: &fn(v: A))) -> @[A] {
let mut vec: @[A] = @[];
unsafe { raw::reserve(&mut vec, size); }
builder(|x| unsafe { raw::push(&mut vec, x) });
return unsafe { transmute(vec) };
}
/**
* Builds a vector by calling a provided function with an argument
* function that pushes an element to the back of a vector.
*
* # Arguments
*
* * builder - A function that will construct the vector. It receives
* as an argument a function that will push an element
* onto the vector being constructed.
*/
#[inline]
pub fn build<A>(builder: &fn(push: &fn(v: A))) -> @[A] {
build_sized(4, builder)
}
/**
* Builds a vector by calling a provided function with an argument
* function that pushes an element to the back of a vector.
* This version takes an initial size for the vector.
*
* # Arguments
*
* * size - An option, maybe containing initial size of the vector to reserve
* * builder - A function that will construct the vector. It receives
* as an argument a function that will push an element
* onto the vector being constructed.
*/
#[inline]
pub fn build_sized_opt<A>(size: Option<uint>,
builder: &fn(push: &fn(v: A)))
-> @[A] {
build_sized(size.get_or_default(4), builder)
}
// Appending
/// Iterates over the `rhs` vector, copying each element and appending it to the
/// `lhs`. Afterwards, the `lhs` is then returned for use again.
#[inline]
pub fn append<T:Copy>(lhs: @[T], rhs: &[T]) -> @[T] {
do build_sized(lhs.len() + rhs.len()) |push| {
for lhs.iter().advance |x| { push(copy *x); }
for uint::range(0, rhs.len()) |i| { push(copy rhs[i]); }
}
}
/// Apply a function to each element of a vector and return the results
pub fn map<T, U>(v: &[T], f: &fn(x: &T) -> U) -> @[U] {
do build_sized(v.len()) |push| {
for v.iter().advance |elem| {
push(f(elem));
}
}
}
/**
* Creates and initializes an immutable vector.
*
* Creates an immutable vector of size `n_elts` and initializes the elements
* to the value returned by the function `op`.
*/
pub fn from_fn<T>(n_elts: uint, op: &fn(uint) -> T) -> @[T] {
do build_sized(n_elts) |push| {
let mut i: uint = 0u;
while i < n_elts { push(op(i)); i += 1u; }
}
}
/**
* Creates and initializes an immutable vector.
*
* Creates an immutable vector of size `n_elts` and initializes the elements
* to the value `t`.
*/
pub fn from_elem<T:Copy>(n_elts: uint, t: T) -> @[T] {
do build_sized(n_elts) |push| {
let mut i: uint = 0u;
while i < n_elts { push(copy t); i += 1u; }
}
}
/**
* Creates and initializes an immutable managed vector by moving all the
* elements from an owned vector.
*/
pub fn to_managed_consume<T>(v: ~[T]) -> @[T] {
let mut av = @[];
unsafe {
raw::reserve(&mut av, v.len());
for v.consume_iter().advance |x| {
raw::push(&mut av, x);
}
transmute(av)
}
}
/**
* Creates and initializes an immutable managed vector by copying all the
* elements of a slice.
*/
pub fn to_managed<T:Copy>(v: &[T]) -> @[T] {
from_fn(v.len(), |i| copy v[i])
}
#[cfg(not(test))]
pub mod traits {
use at_vec::append;
use vec::Vector;
use kinds::Copy;
use ops::Add;
impl<'self,T:Copy, V: Vector<T>> Add<V,@[T]> for @[T] {
#[inline]
fn add(&self, rhs: &V) -> @[T] {
append(*self, rhs.as_slice())
}
}
}
#[cfg(test)]
pub mod traits {}
pub mod raw {
use at_vec::{capacity, rustrt};
use cast::{transmute, transmute_copy};
use libc;
use ptr;
use sys;
use uint;
use unstable::intrinsics::{move_val_init};
use vec;
#[cfg(stage0)]
use intrinsic::{get_tydesc};
#[cfg(not(stage0))]
use unstable::intrinsics::{get_tydesc};
pub type VecRepr = vec::raw::VecRepr;
pub type SliceRepr = vec::raw::SliceRepr;
/**
* Sets the length of a vector
*
* This will explicitly set the size of the vector, without actually
* modifing its buffers, so it is up to the caller to ensure that
* the vector is actually the specified size.
*/
#[inline]
pub unsafe fn set_len<T>(v: @[T], new_len: uint) {
let repr: **mut VecRepr = transmute(&v);
(**repr).unboxed.fill = new_len * sys::size_of::<T>();
}
/**
* Pushes a new value onto this vector.
*/
#[inline]
pub unsafe fn push<T>(v: &mut @[T], initval: T) {
let repr: **VecRepr = transmute_copy(&v);
let fill = (**repr).unboxed.fill;
if (**repr).unboxed.alloc > fill {
push_fast(v, initval);
} else {
push_slow(v, initval);
}
}
#[inline] // really pretty please
unsafe fn push_fast<T>(v: &mut @[T], initval: T) {
let repr: **mut VecRepr = ::cast::transmute(v);
let fill = (**repr).unboxed.fill;
(**repr).unboxed.fill += sys::size_of::<T>();
let p = &((**repr).unboxed.data);
let p = ptr::offset(p, fill) as *mut T;
move_val_init(&mut(*p), initval);
}
unsafe fn push_slow<T>(v: &mut @[T], initval: T) {
reserve_at_least(&mut *v, v.len() + 1u);
push_fast(v, initval);
}
/**
* Reserves capacity for exactly `n` elements in the given vector.
*
* If the capacity for `v` is already equal to or greater than the
* requested capacity, then no action is taken.
*
* # Arguments
*
* * v - A vector
* * n - The number of elements to reserve space for
*/
pub unsafe fn reserve<T>(v: &mut @[T], n: uint) {
// Only make the (slow) call into the runtime if we have to
if capacity(*v) < n {
let ptr: **VecRepr = transmute(v);
rustrt::vec_reserve_shared_actual(get_tydesc::<T>(),
ptr, n as libc::size_t);
}
}
/**
* Reserves capacity for at least `n` elements in the given vector.
*
* This function will over-allocate in order to amortize the
* allocation costs in scenarios where the caller may need to
* repeatedly reserve additional space.
*
* If the capacity for `v` is already equal to or greater than the
* requested capacity, then no action is taken.
*
* # Arguments
*
* * v - A vector
* * n - The number of elements to reserve space for
*/
pub unsafe fn reserve_at_least<T>(v: &mut @[T], n: uint) {
reserve(v, uint::next_power_of_two(n));
}
}
#[cfg(test)]
mod test {
use super::*;
use uint;
#[test]
fn test() {
// Some code that could use that, then:
fn seq_range(lo: uint, hi: uint) -> @[uint] {
do build |push| {
for uint::range(lo, hi) |i| {
push(i);
}
}
}
assert_eq!(seq_range(10, 15), @[10, 11, 12, 13, 14]);
assert_eq!(from_fn(5, |x| x+1), @[1, 2, 3, 4, 5]);
assert_eq!(from_elem(5, 3.14), @[3.14, 3.14, 3.14, 3.14, 3.14]);
}
#[test]
fn append_test() {
assert_eq!(@[1,2,3] + &[4,5,6], @[1,2,3,4,5,6]);
}
#[test]
fn test_to_managed_consume() {
assert_eq!(to_managed_consume::<int>(~[]), @[]);
assert_eq!(to_managed_consume(~[true]), @[true]);
assert_eq!(to_managed_consume(~[1, 2, 3, 4, 5]), @[1, 2, 3, 4, 5]);
assert_eq!(to_managed_consume(~[~"abc", ~"123"]), @[~"abc", ~"123"]);
assert_eq!(to_managed_consume(~[~[42]]), @[~[42]]);
}
#[test]
fn test_to_managed() {
assert_eq!(to_managed::<int>([]), @[]);
assert_eq!(to_managed([true]), @[true]);
assert_eq!(to_managed([1, 2, 3, 4, 5]), @[1, 2, 3, 4, 5]);
assert_eq!(to_managed([@"abc", @"123"]), @[@"abc", @"123"]);
assert_eq!(to_managed([@[42]]), @[@[42]]);
}
}