rust/src/lib/_int.rs
Jeffrey Yasskin 581a95a804 Add an int->str conversion function.
The test currently fails because string equality isn't implemented.
2010-08-06 17:25:27 -07:00

91 lines
2.1 KiB
Rust

import std.sys;
fn add(int x, int y) -> int { ret x + y; }
fn sub(int x, int y) -> int { ret x - y; }
fn mul(int x, int y) -> int { ret x * y; }
fn div(int x, int y) -> int { ret x / y; }
fn rem(int x, int y) -> int { ret x % y; }
fn lt(int x, int y) -> bool { ret x < y; }
fn le(int x, int y) -> bool { ret x <= y; }
fn eq(int x, int y) -> bool { ret x == y; }
fn ne(int x, int y) -> bool { ret x != y; }
fn ge(int x, int y) -> bool { ret x >= y; }
fn gt(int x, int y) -> bool { ret x > y; }
fn positive(int x) -> bool { ret x > 0; }
fn negative(int x) -> bool { ret x < 0; }
fn nonpositive(int x) -> bool { ret x <= 0; }
fn nonnegative(int x) -> bool { ret x >= 0; }
iter range(mutable int lo, int hi) -> int {
while (lo < hi) {
put lo;
lo += 1;
}
}
iter urange(mutable uint lo, uint hi) -> uint {
while (lo < hi) {
put lo;
lo += 1u;
}
}
fn next_power_of_two(uint n) -> uint {
// FIXME change |* uint(4)| below to |* uint(8) / uint(2)| and watch the
// world explode.
let uint halfbits = sys.rustrt.size_of[uint]() * 4u;
let uint tmp = n - 1u;
let uint shift = 1u;
while (shift <= halfbits) {
tmp |= tmp >> shift;
shift <<= 1u;
}
ret tmp + 1u;
}
fn uto_str(mutable uint n, uint radix) -> str
{
check (0u < radix && radix <= 16u);
fn digit(uint n) -> str {
alt (n) {
case (0u) { ret "0"; }
case (1u) { ret "1"; }
case (2u) { ret "2"; }
case (3u) { ret "3"; }
case (4u) { ret "4"; }
case (5u) { ret "5"; }
case (6u) { ret "6"; }
case (7u) { ret "7"; }
case (8u) { ret "8"; }
case (9u) { ret "9"; }
case (10u) { ret "a"; }
case (11u) { ret "b"; }
case (12u) { ret "c"; }
case (13u) { ret "d"; }
case (14u) { ret "e"; }
case (15u) { ret "f"; }
}
}
if (n == 0u) { ret "0"; }
let str s = "";
while (n > 0u) {
s = digit(n % radix) + s;
n /= radix;
}
ret s;
}
fn to_str(mutable int n, uint radix) -> str
{
check (0u < radix && radix <= 16u);
if (n < 0) {
ret "-" + uto_str((-n) as uint, radix);
} else {
ret uto_str(n as uint, radix);
}
}