115 lines
3.1 KiB
Rust
115 lines
3.1 KiB
Rust
// Copyright 2013 The Rust Project Developers. See the COPYRIGHT
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// file at the top-level directory of this distribution and at
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// http://rust-lang.org/COPYRIGHT.
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//
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// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
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// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
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// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
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// option. This file may not be copied, modified, or distributed
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// except according to those terms.
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use std::int;
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use std::uint;
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fn uint_range(lo: uint, hi: uint, it: &fn(uint) -> bool) -> bool {
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range(lo, hi).advance(it)
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}
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fn int_range(lo: int, hi: int, it: &fn(int) -> bool) -> bool {
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range(lo, hi).advance(it)
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}
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fn uint_range_rev(hi: uint, lo: uint, it: &fn(uint) -> bool) -> bool {
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uint::range_rev(hi, lo, it)
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}
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fn int_range_rev(hi: int, lo: int, it: &fn(int) -> bool) -> bool {
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int::range_rev(hi, lo, it)
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}
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fn int_range_step(a: int, b: int, step: int, it: &fn(int) -> bool) -> bool {
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int::range_step(a, b, step, it)
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}
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fn uint_range_step(a: uint, b: uint, step: int, it: &fn(uint) -> bool) -> bool {
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uint::range_step(a, b, step, it)
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}
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pub fn main() {
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// int and uint have same result for
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// Sum{100 > i >= 2} == (Sum{1 <= i <= 99} - 1) == n*(n+1)/2 - 1 for n=99
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let mut sum = 0u;
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for uint_range_rev(100, 2) |i| {
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sum += i;
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}
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assert_eq!(sum, 4949);
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let mut sum = 0i;
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for int_range_rev(100, 2) |i| {
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sum += i;
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}
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assert_eq!(sum, 4949);
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// elements are visited in correct order
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let primes = [2,3,5,7,11];
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let mut prod = 1i;
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for uint_range_rev(5, 0) |i| {
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printfln!("uint 4 downto 0: %u", i);
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prod *= int::pow(primes[i], i);
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}
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assert_eq!(prod, 11*11*11*11*7*7*7*5*5*3*1);
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let mut prod = 1i;
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for int_range_rev(5, 0) |i| {
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printfln!("int 4 downto 0: %d", i);
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prod *= int::pow(primes[i], i as uint);
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}
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assert_eq!(prod, 11*11*11*11*7*7*7*5*5*3*1);
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// range and range_rev are symmetric.
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let mut sum_up = 0u;
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for uint_range(10, 30) |i| {
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sum_up += i;
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}
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let mut sum_down = 0u;
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for uint_range_rev(30, 10) |i| {
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sum_down += i;
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}
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assert_eq!(sum_up, sum_down);
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let mut sum_up = 0;
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for int_range(-20, 10) |i| {
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sum_up += i;
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}
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let mut sum_down = 0;
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for int_range_rev(10, -20) |i| {
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sum_down += i;
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}
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assert_eq!(sum_up, sum_down);
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// empty ranges
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for int_range_rev(10, 10) |_| {
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fail!("range should be empty when start == stop");
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}
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for uint_range_rev(0, 1) |_| {
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fail!("range should be empty when start-1 underflows");
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}
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// range iterations do not wrap/underflow
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let mut uflo_loop_visited = ~[];
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for int_range_step(int::min_value+15, int::min_value, -4) |x| {
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uflo_loop_visited.push(x - int::min_value);
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}
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assert_eq!(uflo_loop_visited, ~[15, 11, 7, 3]);
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let mut uflo_loop_visited = ~[];
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for uint_range_step(uint::min_value+15, uint::min_value, -4) |x| {
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uflo_loop_visited.push(x - uint::min_value);
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}
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assert_eq!(uflo_loop_visited, ~[15, 11, 7, 3]);
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}
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