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/*
Module: int
*/
/*
Const: max_value
The maximum value of an integer
*/
// FIXME: Find another way to access the machine word size in a const expr
#[cfg(target_arch="x86")]
const max_value: int = (-1 << 31)-1;
#[cfg(target_arch="x86_64")]
const max_value: int = (-1 << 63)-1;
/*
Const: min_value
The minumum value of an integer
*/
#[cfg(target_arch="x86")]
const min_value: int = -1 << 31;
#[cfg(target_arch="x86_64")]
const min_value: int = -1 << 63;
/* Function: add */
pure fn add(x: int, y: int) -> int { ret x + y; }
/* Function: sub */
pure fn sub(x: int, y: int) -> int { ret x - y; }
/* Function: mul */
pure fn mul(x: int, y: int) -> int { ret x * y; }
/* Function: div */
pure fn div(x: int, y: int) -> int { ret x / y; }
/* Function: rem */
pure fn rem(x: int, y: int) -> int { ret x % y; }
/* Predicate: lt */
pure fn lt(x: int, y: int) -> bool { ret x < y; }
/* Predicate: le */
pure fn le(x: int, y: int) -> bool { ret x <= y; }
/* Predicate: eq */
pure fn eq(x: int, y: int) -> bool { ret x == y; }
/* Predicate: ne */
pure fn ne(x: int, y: int) -> bool { ret x != y; }
/* Predicate: ge */
pure fn ge(x: int, y: int) -> bool { ret x >= y; }
/* Predicate: gt */
pure fn gt(x: int, y: int) -> bool { ret x > y; }
/* Predicate: positive */
pure fn positive(x: int) -> bool { ret x > 0; }
/* Predicate: negative */
pure fn negative(x: int) -> bool { ret x < 0; }
/* Predicate: nonpositive */
pure fn nonpositive(x: int) -> bool { ret x <= 0; }
/* Predicate: nonnegative */
pure fn nonnegative(x: int) -> bool { ret x >= 0; }
// FIXME: Make sure this works with negative integers.
/*
Function: hash
Produce a uint suitable for use in a hash table
*/
fn hash(x: int) -> uint { ret x as uint; }
/*
Function: range
Iterate over the range [`lo`..`hi`)
*/
fn range(lo: int, hi: int, it: block(int)) {
let i = lo;
while i < hi { it(i); i += 1; }
}
/*
Function: parse_buf
Parse a buffer of bytes
Parameters:
buf - A byte buffer
radix - The base of the number
Failure:
buf must not be empty
*/
fn parse_buf(buf: [u8], radix: uint) -> int {
if vec::len::<u8>(buf) == 0u {
log_err "parse_buf(): buf is empty";
fail;
}
let i = vec::len::<u8>(buf) - 1u;
let start = 0u;
let power = 1;
if buf[0] == ('-' as u8) {
power = -1;
start = 1u;
}
let n = 0;
while true {
let digit = char::to_digit(buf[i] as char);
if (digit as uint) >= radix {
fail;
}
n += (digit as int) * power;
power *= radix as int;
if i <= start { ret n; }
i -= 1u;
}
fail;
}
/*
Function: from_str
Parse a string to an int
Failure:
s must not be empty
*/
fn from_str(s: str) -> int { parse_buf(str::bytes(s), 10u) }
/*
Function: to_str
Convert to a string in a given base
*/
fn to_str(n: int, radix: uint) -> str {
assert (0u < radix && radix <= 16u);
ret if n < 0 {
"-" + uint::to_str(-n as uint, radix)
} else { uint::to_str(n as uint, radix) };
}
/*
Function: str
Convert to a string
*/
fn str(i: int) -> str { ret to_str(i, 10u); }
/*
Function: pow
Returns `base` raised to the power of `exponent`
*/
fn pow(base: int, exponent: uint) -> int {
if exponent == 0u { ret 1; } //Not mathemtically true if [base == 0]
if base == 0 { ret 0; }
let my_pow = exponent;
let acc = 1;
let multiplier = base;
while(my_pow > 0u) {
if my_pow % 2u == 1u {
acc *= multiplier;
}
my_pow /= 2u;
multiplier *= multiplier;
}
ret acc;
}
// Local Variables:
// mode: rust;
// fill-column: 78;
// indent-tabs-mode: nil
// c-basic-offset: 4
// buffer-file-coding-system: utf-8-unix
// End:
|
