291 lines
8.4 KiB
Rust
291 lines
8.4 KiB
Rust
#[doc = "Operations and constants for `uint`"];
|
|
|
|
const min_value: uint = 0u;
|
|
const max_value: uint = 0u - 1u;
|
|
|
|
pure fn min(x: uint, y: uint) -> uint { if x < y { x } else { y } }
|
|
pure fn max(x: uint, y: uint) -> uint { if x > y { x } else { y } }
|
|
|
|
pure fn add(x: uint, y: uint) -> uint { ret x + y; }
|
|
pure fn sub(x: uint, y: uint) -> uint { ret x - y; }
|
|
pure fn mul(x: uint, y: uint) -> uint { ret x * y; }
|
|
pure fn div(x: uint, y: uint) -> uint { ret x / y; }
|
|
pure fn rem(x: uint, y: uint) -> uint { ret x % y; }
|
|
|
|
pure fn lt(x: uint, y: uint) -> bool { ret x < y; }
|
|
pure fn le(x: uint, y: uint) -> bool { ret x <= y; }
|
|
pure fn eq(x: uint, y: uint) -> bool { ret x == y; }
|
|
pure fn ne(x: uint, y: uint) -> bool { ret x != y; }
|
|
pure fn ge(x: uint, y: uint) -> bool { ret x >= y; }
|
|
pure fn gt(x: uint, y: uint) -> bool { ret x > y; }
|
|
|
|
|
|
#[doc = "
|
|
Divide two numbers, return the result, rounded up.
|
|
|
|
# Arguments
|
|
|
|
* x - an integer
|
|
* y - an integer distinct from 0u
|
|
|
|
# Return value
|
|
|
|
The smallest integer `q` such that `x/y <= q`.
|
|
"]
|
|
pure fn div_ceil(x: uint, y: uint) -> uint {
|
|
let div = div(x, y);
|
|
if x % y == 0u { ret div;}
|
|
else { ret div + 1u; }
|
|
}
|
|
|
|
#[doc = "
|
|
Divide two numbers, return the result, rounded to the closest integer.
|
|
|
|
# Arguments
|
|
|
|
* x - an integer
|
|
* y - an integer distinct from 0u
|
|
|
|
# Return value
|
|
|
|
The integer `q` closest to `x/y`.
|
|
"]
|
|
pure fn div_round(x: uint, y: uint) -> uint {
|
|
let div = div(x, y);
|
|
if x % y * 2u < y { ret div;}
|
|
else { ret div + 1u; }
|
|
}
|
|
|
|
#[doc = "
|
|
Divide two numbers, return the result, rounded down.
|
|
|
|
Note: This is the same function as `div`.
|
|
|
|
# Arguments
|
|
|
|
* x - an integer
|
|
* y - an integer distinct from 0u
|
|
|
|
# Return value
|
|
|
|
The smallest integer `q` such that `x/y <= q`. This
|
|
is either `x/y` or `x/y + 1`.
|
|
"]
|
|
pure fn div_floor(x: uint, y: uint) -> uint { ret x / y; }
|
|
|
|
#[doc = "Produce a uint suitable for use in a hash table"]
|
|
pure fn hash(x: uint) -> uint { ret x; }
|
|
|
|
#[doc = "Iterate over the range [`lo`..`hi`)"]
|
|
#[inline(always)]
|
|
fn range(lo: uint, hi: uint, it: fn(uint)) {
|
|
let mut i = lo;
|
|
while i < hi { it(i); i += 1u; }
|
|
}
|
|
|
|
#[doc = "
|
|
Iterate over the range [`lo`..`hi`), or stop when requested
|
|
|
|
# Arguments
|
|
|
|
* lo - The integer at which to start the loop (included)
|
|
* hi - The integer at which to stop the loop (excluded)
|
|
* it - A block to execute with each consecutive integer of the range.
|
|
Return `true` to continue, `false` to stop.
|
|
|
|
# Return value
|
|
|
|
`true` If execution proceeded correctly, `false` if it was interrupted,
|
|
that is if `it` returned `false` at any point.
|
|
"]
|
|
fn iterate(lo: uint, hi: uint, it: fn(uint) -> bool) -> bool {
|
|
let mut i = lo;
|
|
while i < hi {
|
|
if (!it(i)) { ret false; }
|
|
i += 1u;
|
|
}
|
|
ret true;
|
|
}
|
|
|
|
#[doc = "Returns the smallest power of 2 greater than or equal to `n`"]
|
|
fn next_power_of_two(n: uint) -> uint {
|
|
let halfbits: uint = sys::size_of::<uint>() * 4u;
|
|
let mut tmp: uint = n - 1u;
|
|
let mut shift: uint = 1u;
|
|
while shift <= halfbits { tmp |= tmp >> shift; shift <<= 1u; }
|
|
ret tmp + 1u;
|
|
}
|
|
|
|
#[doc = "
|
|
Parse a buffer of bytes
|
|
|
|
# Arguments
|
|
|
|
* buf - A byte buffer
|
|
* radix - The base of the number
|
|
|
|
# Failure
|
|
|
|
`buf` must not be empty
|
|
"]
|
|
fn parse_buf(buf: [u8], radix: uint) -> option<uint> {
|
|
if vec::len(buf) == 0u { ret none; }
|
|
let mut i = vec::len(buf) - 1u;
|
|
let mut power = 1u;
|
|
let mut n = 0u;
|
|
loop {
|
|
alt char::to_digit(buf[i] as char, radix) {
|
|
some(d) { n += d * power; }
|
|
none { ret none; }
|
|
}
|
|
power *= radix;
|
|
if i == 0u { ret some(n); }
|
|
i -= 1u;
|
|
};
|
|
}
|
|
|
|
#[doc = "Parse a string to an int"]
|
|
fn from_str(s: str) -> option<uint> { parse_buf(str::bytes(s), 10u) }
|
|
|
|
#[doc = "Convert to a string in a given base"]
|
|
fn to_str(num: uint, radix: uint) -> str {
|
|
let mut n = num;
|
|
assert (0u < radix && radix <= 16u);
|
|
fn digit(n: uint) -> char {
|
|
ret alt n {
|
|
0u { '0' }
|
|
1u { '1' }
|
|
2u { '2' }
|
|
3u { '3' }
|
|
4u { '4' }
|
|
5u { '5' }
|
|
6u { '6' }
|
|
7u { '7' }
|
|
8u { '8' }
|
|
9u { '9' }
|
|
10u { 'a' }
|
|
11u { 'b' }
|
|
12u { 'c' }
|
|
13u { 'd' }
|
|
14u { 'e' }
|
|
15u { 'f' }
|
|
_ { fail }
|
|
};
|
|
}
|
|
if n == 0u { ret "0"; }
|
|
let mut s: str = "";
|
|
while n != 0u {
|
|
s += str::from_byte(digit(n % radix) as u8);
|
|
n /= radix;
|
|
}
|
|
let mut s1: str = "";
|
|
let mut len: uint = str::len(s);
|
|
while len != 0u { len -= 1u; s1 += str::from_byte(s[len]); }
|
|
ret s1;
|
|
}
|
|
|
|
#[doc = "Convert to a string"]
|
|
fn str(i: uint) -> str { ret to_str(i, 10u); }
|
|
|
|
#[doc = "Computes the bitwise complement"]
|
|
pure fn compl(i: uint) -> uint {
|
|
max_value ^ i
|
|
}
|
|
|
|
#[cfg(test)]
|
|
mod tests {
|
|
|
|
#[test]
|
|
fn test_from_str() {
|
|
assert uint::from_str("0") == some(0u);
|
|
assert uint::from_str("3") == some(3u);
|
|
assert uint::from_str("10") == some(10u);
|
|
assert uint::from_str("123456789") == some(123456789u);
|
|
assert uint::from_str("00100") == some(100u);
|
|
|
|
assert uint::from_str("") == none;
|
|
assert uint::from_str(" ") == none;
|
|
assert uint::from_str("x") == none;
|
|
}
|
|
|
|
#[Test]
|
|
fn test_parse_buf() {
|
|
import str::bytes;
|
|
assert uint::parse_buf(bytes("123"), 10u) == some(123u);
|
|
assert uint::parse_buf(bytes("1001"), 2u) == some(9u);
|
|
assert uint::parse_buf(bytes("123"), 8u) == some(83u);
|
|
assert uint::parse_buf(bytes("123"), 16u) == some(291u);
|
|
assert uint::parse_buf(bytes("ffff"), 16u) == some(65535u);
|
|
assert uint::parse_buf(bytes("z"), 36u) == some(35u);
|
|
|
|
assert uint::parse_buf(str::bytes("Z"), 10u) == none;
|
|
assert uint::parse_buf(str::bytes("_"), 2u) == none;
|
|
}
|
|
|
|
#[test]
|
|
fn test_next_power_of_two() {
|
|
assert (uint::next_power_of_two(0u) == 0u);
|
|
assert (uint::next_power_of_two(1u) == 1u);
|
|
assert (uint::next_power_of_two(2u) == 2u);
|
|
assert (uint::next_power_of_two(3u) == 4u);
|
|
assert (uint::next_power_of_two(4u) == 4u);
|
|
assert (uint::next_power_of_two(5u) == 8u);
|
|
assert (uint::next_power_of_two(6u) == 8u);
|
|
assert (uint::next_power_of_two(7u) == 8u);
|
|
assert (uint::next_power_of_two(8u) == 8u);
|
|
assert (uint::next_power_of_two(9u) == 16u);
|
|
assert (uint::next_power_of_two(10u) == 16u);
|
|
assert (uint::next_power_of_two(11u) == 16u);
|
|
assert (uint::next_power_of_two(12u) == 16u);
|
|
assert (uint::next_power_of_two(13u) == 16u);
|
|
assert (uint::next_power_of_two(14u) == 16u);
|
|
assert (uint::next_power_of_two(15u) == 16u);
|
|
assert (uint::next_power_of_two(16u) == 16u);
|
|
assert (uint::next_power_of_two(17u) == 32u);
|
|
assert (uint::next_power_of_two(18u) == 32u);
|
|
assert (uint::next_power_of_two(19u) == 32u);
|
|
assert (uint::next_power_of_two(20u) == 32u);
|
|
assert (uint::next_power_of_two(21u) == 32u);
|
|
assert (uint::next_power_of_two(22u) == 32u);
|
|
assert (uint::next_power_of_two(23u) == 32u);
|
|
assert (uint::next_power_of_two(24u) == 32u);
|
|
assert (uint::next_power_of_two(25u) == 32u);
|
|
assert (uint::next_power_of_two(26u) == 32u);
|
|
assert (uint::next_power_of_two(27u) == 32u);
|
|
assert (uint::next_power_of_two(28u) == 32u);
|
|
assert (uint::next_power_of_two(29u) == 32u);
|
|
assert (uint::next_power_of_two(30u) == 32u);
|
|
assert (uint::next_power_of_two(31u) == 32u);
|
|
assert (uint::next_power_of_two(32u) == 32u);
|
|
assert (uint::next_power_of_two(33u) == 64u);
|
|
assert (uint::next_power_of_two(34u) == 64u);
|
|
assert (uint::next_power_of_two(35u) == 64u);
|
|
assert (uint::next_power_of_two(36u) == 64u);
|
|
assert (uint::next_power_of_two(37u) == 64u);
|
|
assert (uint::next_power_of_two(38u) == 64u);
|
|
assert (uint::next_power_of_two(39u) == 64u);
|
|
}
|
|
|
|
#[test]
|
|
fn test_overflows() {
|
|
assert (uint::max_value > 0u);
|
|
assert (uint::min_value <= 0u);
|
|
assert (uint::min_value + uint::max_value + 1u == 0u);
|
|
}
|
|
|
|
#[test]
|
|
fn test_div() {
|
|
assert(uint::div_floor(3u, 4u) == 0u);
|
|
assert(uint::div_ceil(3u, 4u) == 1u);
|
|
assert(uint::div_round(3u, 4u) == 1u);
|
|
}
|
|
}
|
|
|
|
// Local Variables:
|
|
// mode: rust;
|
|
// fill-column: 78;
|
|
// indent-tabs-mode: nil
|
|
// c-basic-offset: 4
|
|
// buffer-file-coding-system: utf-8-unix
|
|
// End:
|