Refactored int/uint range code in preparation for change to range_rev semantics.
Also added unit tests of range code to test refactoring. The num-range-rev.rs test will need to be updated when the range_rev semantics change.
This commit is contained in:
parent
41dcec2fe1
commit
3c19f1bca8
|
@ -29,28 +29,38 @@ pub static bytes : uint = ($bits / 8);
|
|||
pub static min_value: $T = (-1 as $T) << (bits - 1);
|
||||
pub static max_value: $T = min_value - 1 as $T;
|
||||
|
||||
///
|
||||
/// Iterate over the range [`lo`..`hi`)
|
||||
///
|
||||
/// # Arguments
|
||||
///
|
||||
/// * `lo` - lower bound, inclusive
|
||||
/// * `hi` - higher bound, exclusive
|
||||
///
|
||||
/// # Examples
|
||||
/// ~~~
|
||||
/// let mut sum = 0;
|
||||
/// for int::range(1, 5) |i| {
|
||||
/// sum += i;
|
||||
/// }
|
||||
/// assert!(sum == 10);
|
||||
/// ~~~
|
||||
///
|
||||
enum Range { Closed, HalfOpen }
|
||||
|
||||
#[inline]
|
||||
pub fn range_step(start: $T, stop: $T, step: $T, it: &fn($T) -> bool) -> bool {
|
||||
///
|
||||
/// Iterate through a range with a given step value.
|
||||
///
|
||||
/// Let `term` denote the closed interval `[stop-step,stop]` if `r` is Closed;
|
||||
/// otherwise `term` denotes the half-open interval `[stop-step,stop)`.
|
||||
/// Iterates through the range `[x_0, x_1, ..., x_n]` where
|
||||
/// `x_j == start + step*j`, and `x_n` lies in the interval `term`.
|
||||
///
|
||||
/// If no such nonnegative integer `n` exists, then the iteration range
|
||||
/// is empty.
|
||||
///
|
||||
fn range_step_core(start: $T, stop: $T, step: $T, r: Range, it: &fn($T) -> bool) -> bool {
|
||||
let mut i = start;
|
||||
if step == 0 {
|
||||
fail!(~"range_step called with step == 0");
|
||||
} else if step == (1 as $T) { // elide bounds check to tighten loop
|
||||
while i < stop {
|
||||
if !it(i) { return false; }
|
||||
// no need for overflow check;
|
||||
// cannot have i + 1 > max_value because i < stop <= max_value
|
||||
i += (1 as $T);
|
||||
}
|
||||
} else if step == (-1 as $T) { // elide bounds check to tighten loop
|
||||
while i > stop {
|
||||
if !it(i) { return false; }
|
||||
// no need for underflow check;
|
||||
// cannot have i - 1 < min_value because i > stop >= min_value
|
||||
i -= (1 as $T);
|
||||
}
|
||||
} else if step > 0 { // ascending
|
||||
while i < stop {
|
||||
if !it(i) { return false; }
|
||||
|
@ -66,9 +76,55 @@ pub fn range_step(start: $T, stop: $T, step: $T, it: &fn($T) -> bool) -> bool {
|
|||
i += step;
|
||||
}
|
||||
}
|
||||
return true;
|
||||
match r {
|
||||
HalfOpen => return true,
|
||||
Closed => return (i != stop || it(i))
|
||||
}
|
||||
}
|
||||
|
||||
#[inline]
|
||||
///
|
||||
/// Iterate through the range [`start`..`stop`) with a given step value.
|
||||
///
|
||||
/// Iterates through the range `[x_0, x_1, ..., x_n]` where
|
||||
/// * `x_i == start + step*i`, and
|
||||
/// * `n` is the greatest nonnegative integer such that `x_n < stop`
|
||||
///
|
||||
/// (If no such `n` exists, then the iteration range is empty.)
|
||||
///
|
||||
/// # Arguments
|
||||
///
|
||||
/// * `start` - lower bound, inclusive
|
||||
/// * `stop` - higher bound, exclusive
|
||||
///
|
||||
/// # Examples
|
||||
/// ~~~
|
||||
/// let mut sum = 0;
|
||||
/// for int::range(1, 5) |i| {
|
||||
/// sum += i;
|
||||
/// }
|
||||
/// assert!(sum == 10);
|
||||
/// ~~~
|
||||
///
|
||||
pub fn range_step(start: $T, stop: $T, step: $T, it: &fn($T) -> bool) -> bool {
|
||||
range_step_core(start, stop, step, HalfOpen, it)
|
||||
}
|
||||
|
||||
#[inline]
|
||||
///
|
||||
/// Iterate through a range with a given step value.
|
||||
///
|
||||
/// Iterates through the range `[x_0, x_1, ..., x_n]` where
|
||||
/// `x_i == start + step*i` and `x_n <= last < step + x_n`.
|
||||
///
|
||||
/// (If no such nonnegative integer `n` exists, then the iteration
|
||||
/// range is empty.)
|
||||
///
|
||||
pub fn range_step_inclusive(start: $T, last: $T, step: $T, it: &fn($T) -> bool) -> bool {
|
||||
range_step_core(start, last, step, Closed, it)
|
||||
}
|
||||
|
||||
|
||||
#[inline]
|
||||
/// Iterate over the range [`lo`..`hi`)
|
||||
pub fn range(lo: $T, hi: $T, it: &fn($T) -> bool) -> bool {
|
||||
|
|
|
@ -30,32 +30,46 @@ pub static bytes : uint = ($bits / 8);
|
|||
pub static min_value: $T = 0 as $T;
|
||||
pub static max_value: $T = 0 as $T - 1 as $T;
|
||||
|
||||
enum Range { Closed, HalfOpen }
|
||||
|
||||
#[inline]
|
||||
/**
|
||||
* Iterate through a range with a given step value.
|
||||
*
|
||||
* # Examples
|
||||
* ~~~ {.rust}
|
||||
* let nums = [1,2,3,4,5,6,7];
|
||||
*
|
||||
* for uint::range_step(0, nums.len() - 1, 2) |i| {
|
||||
* println(fmt!("%d & %d", nums[i], nums[i+1]));
|
||||
* }
|
||||
* ~~~
|
||||
*/
|
||||
pub fn range_step(start: $T, stop: $T, step: $T_SIGNED, it: &fn($T) -> bool) -> bool {
|
||||
///
|
||||
/// Iterate through a range with a given step value.
|
||||
///
|
||||
/// Let `term` denote the closed interval `[stop-step,stop]` if `r` is Closed;
|
||||
/// otherwise `term` denotes the half-open interval `[stop-step,stop)`.
|
||||
/// Iterates through the range `[x_0, x_1, ..., x_n]` where
|
||||
/// `x_j == start + step*j`, and `x_n` lies in the interval `term`.
|
||||
///
|
||||
/// If no such nonnegative integer `n` exists, then the iteration range
|
||||
/// is empty.
|
||||
///
|
||||
fn range_step_core(start: $T, stop: $T, step: $T_SIGNED, r: Range, it: &fn($T) -> bool) -> bool {
|
||||
let mut i = start;
|
||||
if step == 0 {
|
||||
fail!("range_step called with step == 0");
|
||||
} else if step == (1 as $T_SIGNED) { // elide bounds check to tighten loop
|
||||
while i < stop {
|
||||
if !it(i) { return false; }
|
||||
// no need for overflow check;
|
||||
// cannot have i + 1 > max_value because i < stop <= max_value
|
||||
i += (1 as $T);
|
||||
}
|
||||
if step >= 0 {
|
||||
} else if step == (-1 as $T_SIGNED) { // elide bounds check to tighten loop
|
||||
while i > stop {
|
||||
if !it(i) { return false; }
|
||||
// no need for underflow check;
|
||||
// cannot have i - 1 < min_value because i > stop >= min_value
|
||||
i -= (1 as $T);
|
||||
}
|
||||
} else if step > 0 { // ascending
|
||||
while i < stop {
|
||||
if !it(i) { return false; }
|
||||
// avoiding overflow. break if i + step > max_value
|
||||
if i > max_value - (step as $T) { return true; }
|
||||
i += step as $T;
|
||||
}
|
||||
} else {
|
||||
} else { // descending
|
||||
while i > stop {
|
||||
if !it(i) { return false; }
|
||||
// avoiding underflow. break if i + step < min_value
|
||||
|
@ -63,7 +77,52 @@ pub fn range_step(start: $T, stop: $T, step: $T_SIGNED, it: &fn($T) -> bool) ->
|
|||
i -= -step as $T;
|
||||
}
|
||||
}
|
||||
return true;
|
||||
match r {
|
||||
HalfOpen => return true,
|
||||
Closed => return (i != stop || it(i))
|
||||
}
|
||||
}
|
||||
|
||||
#[inline]
|
||||
///
|
||||
/// Iterate through the range [`start`..`stop`) with a given step value.
|
||||
///
|
||||
/// Iterates through the range `[x_0, x_1, ..., x_n]` where
|
||||
/// - `x_i == start + step*i`, and
|
||||
/// - `n` is the greatest nonnegative integer such that `x_n < stop`
|
||||
///
|
||||
/// (If no such `n` exists, then the iteration range is empty.)
|
||||
///
|
||||
/// # Arguments
|
||||
///
|
||||
/// * `start` - lower bound, inclusive
|
||||
/// * `stop` - higher bound, exclusive
|
||||
///
|
||||
/// # Examples
|
||||
/// ~~~ {.rust}
|
||||
/// let nums = [1,2,3,4,5,6,7];
|
||||
///
|
||||
/// for uint::range_step(0, nums.len() - 1, 2) |i| {
|
||||
/// println(fmt!("%d & %d", nums[i], nums[i+1]));
|
||||
/// }
|
||||
/// ~~~
|
||||
///
|
||||
pub fn range_step(start: $T, stop: $T, step: $T_SIGNED, it: &fn($T) -> bool) -> bool {
|
||||
range_step_core(start, stop, step, HalfOpen, it)
|
||||
}
|
||||
|
||||
#[inline]
|
||||
///
|
||||
/// Iterate through a range with a given step value.
|
||||
///
|
||||
/// Iterates through the range `[x_0, x_1, ..., x_n]` where
|
||||
/// `x_i == start + step*i` and `x_n <= last < step + x_n`.
|
||||
///
|
||||
/// (If no such nonnegative integer `n` exists, then the iteration
|
||||
/// range is empty.)
|
||||
///
|
||||
pub fn range_step_inclusive(start: $T, last: $T, step: $T_SIGNED, it: &fn($T) -> bool) -> bool {
|
||||
range_step_core(start, last, step, Closed, it)
|
||||
}
|
||||
|
||||
#[inline]
|
||||
|
|
|
@ -0,0 +1,114 @@
|
|||
// Copyright 2013 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::int;
|
||||
use std::uint;
|
||||
|
||||
fn uint_range(lo: uint, hi: uint, it: &fn(uint) -> bool) -> bool {
|
||||
uint::range(lo, hi, it)
|
||||
}
|
||||
|
||||
fn int_range(lo: int, hi: int, it: &fn(int) -> bool) -> bool {
|
||||
int::range(lo, hi, it)
|
||||
}
|
||||
|
||||
fn uint_range_rev(hi: uint, lo: uint, it: &fn(uint) -> bool) -> bool {
|
||||
uint::range_rev(hi, lo, it)
|
||||
}
|
||||
|
||||
fn int_range_rev(hi: int, lo: int, it: &fn(int) -> bool) -> bool {
|
||||
int::range_rev(hi, lo, it)
|
||||
}
|
||||
|
||||
fn int_range_step(a: int, b: int, step: int, it: &fn(int) -> bool) -> bool {
|
||||
int::range_step(a, b, step, it)
|
||||
}
|
||||
|
||||
fn uint_range_step(a: uint, b: uint, step: int, it: &fn(uint) -> bool) -> bool {
|
||||
uint::range_step(a, b, step, it)
|
||||
}
|
||||
|
||||
|
||||
pub fn main() {
|
||||
// int and uint have same result for
|
||||
// Sum{100 > i >= 2} == (Sum{1 <= i <= 99} - 1) == n*(n+1)/2 - 1 for n=99
|
||||
let mut sum = 0u;
|
||||
for uint_range_rev(99, 1) |i| {
|
||||
sum += i;
|
||||
}
|
||||
assert_eq!(sum, 4949);
|
||||
|
||||
let mut sum = 0i;
|
||||
for int_range_rev(99, 1) |i| {
|
||||
sum += i;
|
||||
}
|
||||
assert_eq!(sum, 4949);
|
||||
|
||||
|
||||
// elements are visited in correct order
|
||||
let primes = [2,3,5,7,11];
|
||||
let mut prod = 1i;
|
||||
for uint_range_rev(4, 0) |i| {
|
||||
println(fmt!("uint 4 downto 0: %u", i));
|
||||
prod *= int::pow(primes[i], i);
|
||||
}
|
||||
assert_eq!(prod, 11*11*11*11*7*7*7*5*5*3);
|
||||
let mut prod = 1i;
|
||||
for int_range_rev(4, 0) |i| {
|
||||
println(fmt!("int 4 downto 0: %d", i));
|
||||
prod *= int::pow(primes[i], i as uint);
|
||||
}
|
||||
assert_eq!(prod, 11*11*11*11*7*7*7*5*5*3);
|
||||
|
||||
|
||||
// range and range_rev are symmetric.
|
||||
let mut sum_up = 0u;
|
||||
for uint_range(10, 30) |i| {
|
||||
sum_up += i;
|
||||
}
|
||||
let mut sum_down = 0u;
|
||||
for uint_range_rev(29, 9) |i| {
|
||||
sum_down += i;
|
||||
}
|
||||
assert_eq!(sum_up, sum_down);
|
||||
|
||||
let mut sum_up = 0;
|
||||
for int_range(-20, 10) |i| {
|
||||
sum_up += i;
|
||||
}
|
||||
let mut sum_down = 0;
|
||||
for int_range_rev(9, -21) |i| {
|
||||
sum_down += i;
|
||||
}
|
||||
assert_eq!(sum_up, sum_down);
|
||||
|
||||
|
||||
// empty ranges
|
||||
for int_range_rev(10, 10) |_| {
|
||||
fail!("range should be empty when start == stop");
|
||||
}
|
||||
|
||||
for uint_range_rev(0, 1) |_| {
|
||||
// fail!("range should be empty when start-1 underflows");
|
||||
}
|
||||
|
||||
// range iterations do not wrap/underflow
|
||||
let mut uflo_loop_visited = ~[];
|
||||
for int_range_step(int::min_value+15, int::min_value, -4) |x| {
|
||||
uflo_loop_visited.push(x - int::min_value);
|
||||
}
|
||||
assert_eq!(uflo_loop_visited, ~[15, 11, 7, 3]);
|
||||
|
||||
let mut uflo_loop_visited = ~[];
|
||||
for uint_range_step(uint::min_value+15, uint::min_value, -4) |x| {
|
||||
uflo_loop_visited.push(x - uint::min_value);
|
||||
}
|
||||
assert_eq!(uflo_loop_visited, ~[15, 11, 7, 3]);
|
||||
}
|
|
@ -0,0 +1,119 @@
|
|||
// Copyright 2013 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::int;
|
||||
use std::uint;
|
||||
|
||||
fn uint_range(lo: uint, hi: uint, it: &fn(uint) -> bool) -> bool {
|
||||
uint::range(lo, hi, it)
|
||||
}
|
||||
|
||||
fn int_range(lo: int, hi: int, it: &fn(int) -> bool) -> bool {
|
||||
int::range(lo, hi, it)
|
||||
}
|
||||
|
||||
fn int_range_step(a: int, b: int, step: int, it: &fn(int) -> bool) -> bool {
|
||||
int::range_step(a, b, step, it)
|
||||
}
|
||||
|
||||
fn uint_range_step(a: uint, b: uint, s: int, it: &fn(uint) -> bool) -> bool {
|
||||
uint::range_step(a, b, s, it)
|
||||
}
|
||||
|
||||
pub fn main() {
|
||||
println(fmt!("num-range start"));
|
||||
// int and uint have same result for
|
||||
// Sum{2 <= i < 100} == (Sum{1 <= i <= 99} - 1) == n*(n+1)/2 - 1 for n=99
|
||||
let mut sum = 0u;
|
||||
for uint_range(2, 100) |i| {
|
||||
sum += i;
|
||||
}
|
||||
assert_eq!(sum, 4949);
|
||||
|
||||
let mut sum = 0i;
|
||||
for int_range(2, 100) |i| {
|
||||
sum += i;
|
||||
}
|
||||
assert_eq!(sum, 4949);
|
||||
|
||||
|
||||
// elements are visited in correct order
|
||||
let primes = [2,3,5,7];
|
||||
let mut prod = 1i;
|
||||
for uint_range(0, 4) |i| {
|
||||
prod *= int::pow(primes[i], i);
|
||||
}
|
||||
assert_eq!(prod, 1*3*5*5*7*7*7);
|
||||
let mut prod = 1i;
|
||||
for int_range(0, 4) |i| {
|
||||
prod *= int::pow(primes[i], i as uint);
|
||||
}
|
||||
assert_eq!(prod, 1*3*5*5*7*7*7);
|
||||
|
||||
|
||||
// empty ranges
|
||||
for int_range(10, 10) |_| {
|
||||
fail!("range should be empty when start == stop");
|
||||
}
|
||||
|
||||
for uint_range(10, 10) |_| {
|
||||
fail!("range should be empty when start == stop");
|
||||
}
|
||||
|
||||
|
||||
// range iterations do not wrap/overflow
|
||||
let mut oflo_loop_visited = ~[];
|
||||
for uint_range_step(uint::max_value-15, uint::max_value, 4) |x| {
|
||||
oflo_loop_visited.push(uint::max_value - x);
|
||||
}
|
||||
assert_eq!(oflo_loop_visited, ~[15, 11, 7, 3]);
|
||||
|
||||
let mut oflo_loop_visited = ~[];
|
||||
for int_range_step(int::max_value-15, int::max_value, 4) |x| {
|
||||
oflo_loop_visited.push(int::max_value - x);
|
||||
}
|
||||
assert_eq!(oflo_loop_visited, ~[15, 11, 7, 3]);
|
||||
|
||||
|
||||
// range_step never passes nor visits the stop element
|
||||
for int_range_step(0, 21, 3) |x| {
|
||||
assert!(x < 21);
|
||||
}
|
||||
|
||||
// range_step_inclusive will never pass stop element, and may skip it.
|
||||
let mut saw21 = false;
|
||||
for uint::range_step_inclusive(0, 21, 4) |x| {
|
||||
assert!(x <= 21);
|
||||
if x == 21 { saw21 = true; }
|
||||
}
|
||||
assert!(!saw21);
|
||||
let mut saw21 = false;
|
||||
for int::range_step_inclusive(0, 21, 4) |x| {
|
||||
assert!(x <= 21);
|
||||
if x == 21 { saw21 = true; }
|
||||
}
|
||||
assert!(!saw21);
|
||||
|
||||
// range_step_inclusive will never pass stop element, but may visit it.
|
||||
let mut saw21 = false;
|
||||
for uint::range_step_inclusive(0, 21, 3) |x| {
|
||||
assert!(x <= 21);
|
||||
println(fmt!("saw: %u", x));
|
||||
if x == 21 { saw21 = true; }
|
||||
}
|
||||
assert!(saw21);
|
||||
let mut saw21 = false;
|
||||
for int::range_step_inclusive(0, 21, 3) |x| {
|
||||
assert!(x <= 21);
|
||||
if x == 21 { saw21 = true; }
|
||||
}
|
||||
assert!(saw21);
|
||||
|
||||
}
|
Loading…
Reference in New Issue