rust/src/libcore/u64.rs
2011-12-28 11:19:41 -08:00

89 lines
1.6 KiB
Rust

/*
Module: u64
*/
/*
Const: min_value
Return the minimal value for a u64
*/
const min_value: u64 = 0u64;
/*
Const: max_value
Return the maximal value for a u64
*/
const max_value: u64 = 18446744073709551615u64;
/*
Function: to_str
Convert to a string in a given base
*/
fn to_str(n: u64, radix: uint) -> str {
assert (0u < radix && radix <= 16u);
let r64 = radix as u64;
fn digit(n: u64) -> str {
ret alt n {
0u64 { "0" }
1u64 { "1" }
2u64 { "2" }
3u64 { "3" }
4u64 { "4" }
5u64 { "5" }
6u64 { "6" }
7u64 { "7" }
8u64 { "8" }
9u64 { "9" }
10u64 { "a" }
11u64 { "b" }
12u64 { "c" }
13u64 { "d" }
14u64 { "e" }
15u64 { "f" }
_ { fail }
};
}
if n == 0u64 { ret "0"; }
let s = "";
let n = n;
while n > 0u64 { s = digit(n % r64) + s; n /= r64; }
ret s;
}
/*
Function: str
Convert to a string
*/
fn str(n: u64) -> str { ret to_str(n, 10u); }
/*
Function: from_str
Parse a string as an unsigned integer.
*/
fn from_str(buf: str, radix: u64) -> u64 {
if str::byte_len(buf) == 0u {
#error("parse_buf(): buf is empty");
fail;
}
let i = str::byte_len(buf) - 1u;
let power = 1u64, n = 0u64;
while true {
let digit = char::to_digit(buf[i] as char) as u64;
if digit >= radix { fail; }
n += digit * power;
power *= radix;
if i == 0u { ret n; }
i -= 1u;
}
fail;
}