Extract iter

This commit is contained in:
Łukasz Jan Niemier 2016-03-11 01:05:40 +01:00
parent ed076070e6
commit 96e9166b0a
5 changed files with 414 additions and 19 deletions

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@ -23,12 +23,16 @@ optional = true
path = "bigint" path = "bigint"
[dependencies.num-complex] [dependencies.num-complex]
optional = false optional = true
path = "complex" path = "complex"
[dependencies.num-integer] [dependencies.num-integer]
path = "./integer" path = "./integer"
[dependencies.num-iter]
optional = false
path = "iter"
[dependencies.num-rational] [dependencies.num-rational]
optional = true optional = true
path = "rational" path = "rational"
@ -55,6 +59,6 @@ version = "0.3.8"
[features] [features]
bigint = ["num-bigint"] bigint = ["num-bigint"]
complex = [] complex = ["num-complex"]
default = ["bigint", "complex", "rand", "rational", "rustc-serialize"]
rational = ["num-rational"] rational = ["num-rational"]
default = ["bigint", "complex", "rand", "rational", "rustc-serialize"]

14
iter/Cargo.toml Normal file
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@ -0,0 +1,14 @@
[package]
authors = ["Łukasz Jan Niemier <lukasz@niemier.pl>"]
name = "num-iter"
version = "0.1.0"
[dependencies]
[dependencies.num-integer]
optional = false
path = "../integer"
[dependencies.num-traits]
optional = false
path = "../traits"

376
iter/src/lib.rs Normal file
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@ -0,0 +1,376 @@
// Copyright 2013-2014 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.
//! External iterators for generic mathematics
extern crate num_traits as traits;
extern crate num_integer as integer;
use integer::Integer;
use traits::{Zero, One, CheckedAdd, ToPrimitive};
use std::ops::{Add, Sub};
/// An iterator over the range [start, stop)
#[derive(Clone)]
pub struct Range<A> {
state: A,
stop: A,
one: A
}
/// Returns an iterator over the given range [start, stop) (that is, starting
/// at start (inclusive), and ending at stop (exclusive)).
///
/// # Example
///
/// ```rust
/// use num::iter;
///
/// let array = [0, 1, 2, 3, 4];
///
/// for i in iter::range(0, 5) {
/// println!("{}", i);
/// assert_eq!(i, array[i]);
/// }
/// ```
#[inline]
pub fn range<A>(start: A, stop: A) -> Range<A>
where A: Add<A, Output = A> + PartialOrd + Clone + One
{
Range{state: start, stop: stop, one: One::one()}
}
// FIXME: rust-lang/rust#10414: Unfortunate type bound
impl<A> Iterator for Range<A>
where A: Add<A, Output = A> + PartialOrd + Clone + ToPrimitive
{
type Item = A;
#[inline]
fn next(&mut self) -> Option<A> {
if self.state < self.stop {
let result = self.state.clone();
self.state = self.state.clone() + self.one.clone();
Some(result)
} else {
None
}
}
#[inline]
fn size_hint(&self) -> (usize, Option<usize>) {
// This first checks if the elements are representable as i64. If they aren't, try u64 (to
// handle cases like range(huge, huger)). We don't use usize/int because the difference of
// the i64/u64 might lie within their range.
let bound = match self.state.to_i64() {
Some(a) => {
let sz = self.stop.to_i64().map(|b| b.checked_sub(a));
match sz {
Some(Some(bound)) => bound.to_usize(),
_ => None,
}
},
None => match self.state.to_u64() {
Some(a) => {
let sz = self.stop.to_u64().map(|b| b.checked_sub(a));
match sz {
Some(Some(bound)) => bound.to_usize(),
_ => None
}
},
None => None
}
};
match bound {
Some(b) => (b, Some(b)),
// Standard fallback for unbounded/unrepresentable bounds
None => (0, None)
}
}
}
/// `Integer` is required to ensure the range will be the same regardless of
/// the direction it is consumed.
impl<A> DoubleEndedIterator for Range<A>
where A: Integer + Clone + ToPrimitive
{
#[inline]
fn next_back(&mut self) -> Option<A> {
if self.stop > self.state {
self.stop = self.stop.clone() - self.one.clone();
Some(self.stop.clone())
} else {
None
}
}
}
/// An iterator over the range [start, stop]
#[derive(Clone)]
pub struct RangeInclusive<A> {
range: Range<A>,
done: bool,
}
/// Return an iterator over the range [start, stop]
#[inline]
pub fn range_inclusive<A>(start: A, stop: A) -> RangeInclusive<A>
where A: Add<A, Output = A> + PartialOrd + Clone + One
{
RangeInclusive{range: range(start, stop), done: false}
}
impl<A> Iterator for RangeInclusive<A>
where A: Add<A, Output = A> + PartialOrd + Clone + ToPrimitive
{
type Item = A;
#[inline]
fn next(&mut self) -> Option<A> {
match self.range.next() {
Some(x) => Some(x),
None => {
if !self.done && self.range.state == self.range.stop {
self.done = true;
Some(self.range.stop.clone())
} else {
None
}
}
}
}
#[inline]
fn size_hint(&self) -> (usize, Option<usize>) {
let (lo, hi) = self.range.size_hint();
if self.done {
(lo, hi)
} else {
let lo = lo.saturating_add(1);
let hi = match hi {
Some(x) => x.checked_add(1),
None => None
};
(lo, hi)
}
}
}
impl<A> DoubleEndedIterator for RangeInclusive<A>
where A: Sub<A, Output = A> + Integer + Clone + ToPrimitive
{
#[inline]
fn next_back(&mut self) -> Option<A> {
if self.range.stop > self.range.state {
let result = self.range.stop.clone();
self.range.stop = self.range.stop.clone() - self.range.one.clone();
Some(result)
} else if !self.done && self.range.state == self.range.stop {
self.done = true;
Some(self.range.stop.clone())
} else {
None
}
}
}
/// An iterator over the range [start, stop) by `step`. It handles overflow by stopping.
#[derive(Clone)]
pub struct RangeStep<A> {
state: A,
stop: A,
step: A,
rev: bool,
}
/// Return an iterator over the range [start, stop) by `step`. It handles overflow by stopping.
#[inline]
pub fn range_step<A>(start: A, stop: A, step: A) -> RangeStep<A>
where A: CheckedAdd + PartialOrd + Clone + Zero
{
let rev = step < Zero::zero();
RangeStep{state: start, stop: stop, step: step, rev: rev}
}
impl<A> Iterator for RangeStep<A>
where A: CheckedAdd + PartialOrd + Clone
{
type Item = A;
#[inline]
fn next(&mut self) -> Option<A> {
if (self.rev && self.state > self.stop) || (!self.rev && self.state < self.stop) {
let result = self.state.clone();
match self.state.checked_add(&self.step) {
Some(x) => self.state = x,
None => self.state = self.stop.clone()
}
Some(result)
} else {
None
}
}
}
/// An iterator over the range [start, stop] by `step`. It handles overflow by stopping.
#[derive(Clone)]
pub struct RangeStepInclusive<A> {
state: A,
stop: A,
step: A,
rev: bool,
done: bool,
}
/// Return an iterator over the range [start, stop] by `step`. It handles overflow by stopping.
#[inline]
pub fn range_step_inclusive<A>(start: A, stop: A, step: A) -> RangeStepInclusive<A>
where A: CheckedAdd + PartialOrd + Clone + Zero
{
let rev = step < Zero::zero();
RangeStepInclusive{state: start, stop: stop, step: step, rev: rev, done: false}
}
impl<A> Iterator for RangeStepInclusive<A>
where A: CheckedAdd + PartialOrd + Clone + PartialEq
{
type Item = A;
#[inline]
fn next(&mut self) -> Option<A> {
if !self.done && ((self.rev && self.state >= self.stop) ||
(!self.rev && self.state <= self.stop)) {
let result = self.state.clone();
match self.state.checked_add(&self.step) {
Some(x) => self.state = x,
None => self.done = true
}
Some(result)
} else {
None
}
}
}
#[cfg(test)]
mod tests {
use std::usize;
use std::ops::{Add, Mul};
use std::cmp::Ordering;
use {One, ToPrimitive};
#[test]
fn test_range() {
/// A mock type to check Range when ToPrimitive returns None
struct Foo;
impl ToPrimitive for Foo {
fn to_i64(&self) -> Option<i64> { None }
fn to_u64(&self) -> Option<u64> { None }
}
impl Add<Foo> for Foo {
type Output = Foo;
fn add(self, _: Foo) -> Foo {
Foo
}
}
impl PartialEq for Foo {
fn eq(&self, _: &Foo) -> bool {
true
}
}
impl PartialOrd for Foo {
fn partial_cmp(&self, _: &Foo) -> Option<Ordering> {
None
}
}
impl Clone for Foo {
fn clone(&self) -> Foo {
Foo
}
}
impl Mul<Foo> for Foo {
type Output = Foo;
fn mul(self, _: Foo) -> Foo {
Foo
}
}
impl One for Foo {
fn one() -> Foo {
Foo
}
}
assert!(super::range(0, 5).collect::<Vec<isize>>() == vec![0, 1, 2, 3, 4]);
assert!(super::range(-10, -1).collect::<Vec<isize>>() ==
vec![-10, -9, -8, -7, -6, -5, -4, -3, -2]);
assert!(super::range(0, 5).rev().collect::<Vec<isize>>() == vec![4, 3, 2, 1, 0]);
assert_eq!(super::range(200, -5).count(), 0);
assert_eq!(super::range(200, -5).rev().count(), 0);
assert_eq!(super::range(200, 200).count(), 0);
assert_eq!(super::range(200, 200).rev().count(), 0);
assert_eq!(super::range(0, 100).size_hint(), (100, Some(100)));
// this test is only meaningful when sizeof usize < sizeof u64
assert_eq!(super::range(usize::MAX - 1, usize::MAX).size_hint(), (1, Some(1)));
assert_eq!(super::range(-10, -1).size_hint(), (9, Some(9)));
}
#[test]
fn test_range_inclusive() {
assert!(super::range_inclusive(0, 5).collect::<Vec<isize>>() ==
vec![0, 1, 2, 3, 4, 5]);
assert!(super::range_inclusive(0, 5).rev().collect::<Vec<isize>>() ==
vec![5, 4, 3, 2, 1, 0]);
assert_eq!(super::range_inclusive(200, -5).count(), 0);
assert_eq!(super::range_inclusive(200, -5).rev().count(), 0);
assert!(super::range_inclusive(200, 200).collect::<Vec<isize>>() == vec![200]);
assert!(super::range_inclusive(200, 200).rev().collect::<Vec<isize>>() == vec![200]);
}
#[test]
fn test_range_step() {
assert!(super::range_step(0, 20, 5).collect::<Vec<isize>>() ==
vec![0, 5, 10, 15]);
assert!(super::range_step(20, 0, -5).collect::<Vec<isize>>() ==
vec![20, 15, 10, 5]);
assert!(super::range_step(20, 0, -6).collect::<Vec<isize>>() ==
vec![20, 14, 8, 2]);
assert!(super::range_step(200u8, 255, 50).collect::<Vec<u8>>() ==
vec![200u8, 250]);
assert!(super::range_step(200, -5, 1).collect::<Vec<isize>>() == vec![]);
assert!(super::range_step(200, 200, 1).collect::<Vec<isize>>() == vec![]);
}
#[test]
fn test_range_step_inclusive() {
assert!(super::range_step_inclusive(0, 20, 5).collect::<Vec<isize>>() ==
vec![0, 5, 10, 15, 20]);
assert!(super::range_step_inclusive(20, 0, -5).collect::<Vec<isize>>() ==
vec![20, 15, 10, 5, 0]);
assert!(super::range_step_inclusive(20, 0, -6).collect::<Vec<isize>>() ==
vec![20, 14, 8, 2]);
assert!(super::range_step_inclusive(200u8, 255, 50).collect::<Vec<u8>>() ==
vec![200u8, 250]);
assert!(super::range_step_inclusive(200, -5, 1).collect::<Vec<isize>>() ==
vec![]);
assert!(super::range_step_inclusive(200, 200, 1).collect::<Vec<isize>>() ==
vec![200]);
}
}

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@ -57,14 +57,15 @@
html_root_url = "http://rust-num.github.io/num/", html_root_url = "http://rust-num.github.io/num/",
html_playground_url = "http://play.rust-lang.org/")] html_playground_url = "http://play.rust-lang.org/")]
extern crate num_traits; pub extern crate num_traits;
extern crate num_integer; pub extern crate num_integer;
#[cfg(feature = "complex")] pub extern crate num_iter;
extern crate num_complex; #[cfg(feature = "num-complex")]
pub extern crate num_complex;
#[cfg(feature = "num-bigint")] #[cfg(feature = "num-bigint")]
extern crate num_bigint; pub extern crate num_bigint;
#[cfg(feature = "num-rational")] #[cfg(feature = "num-rational")]
extern crate num_rational; pub extern crate num_rational;
#[cfg(feature = "rustc-serialize")] #[cfg(feature = "rustc-serialize")]
extern crate rustc_serialize; extern crate rustc_serialize;
@ -84,7 +85,7 @@ pub use bigint::{BigInt, BigUint};
pub use rational::Rational; pub use rational::Rational;
#[cfg(all(feature = "num-rational", feature="num-bigint"))] #[cfg(all(feature = "num-rational", feature="num-bigint"))]
pub use rational::BigRational; pub use rational::BigRational;
#[cfg(feature = "complex")] #[cfg(feature = "num-complex")]
pub use complex::Complex; pub use complex::Complex;
pub use integer::Integer; pub use integer::Integer;
pub use iter::{range, range_inclusive, range_step, range_step_inclusive}; pub use iter::{range, range_inclusive, range_step, range_step_inclusive};
@ -99,8 +100,8 @@ use std::ops::{Mul};
#[cfg(feature = "num-bigint")] #[cfg(feature = "num-bigint")]
pub use num_bigint as bigint; pub use num_bigint as bigint;
pub use num_complex as complex; pub use num_complex as complex;
pub use num_integer as integers; pub use num_integer as integer;
pub mod iter; pub use num_iter as iter;
pub use num_traits as traits; pub use num_traits as traits;
#[cfg(feature = "num-rational")] #[cfg(feature = "num-rational")]
pub use num_rational as rational; pub use num_rational as rational;

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@ -21,13 +21,13 @@ pub use sign::{Signed, Unsigned};
pub use int::PrimInt; pub use int::PrimInt;
pub use cast::*; pub use cast::*;
mod identities; pub mod identities;
mod sign; pub mod sign;
mod ops; pub mod ops;
mod bounds; pub mod bounds;
mod float; pub mod float;
mod int; pub mod int;
mod cast; pub mod cast;
/// The base trait for numeric types /// The base trait for numeric types
pub trait Num: PartialEq + Zero + One pub trait Num: PartialEq + Zero + One