Copy first batch of material from libstd to libcore.

src/libcore/uint.rs

@@ -0,0 +1,254 @@
+/*
+Module: uint
+*/
+
+/*
+Const: min_value
+
+Return the minimal value for an uint.
+
+This is always 0
+*/
+const min_value: uint = 0u;
+
+/*
+Const: max_value
+
+Return the maximal value for an uint.
+
+This is 2^wordsize - 1
+*/
+const max_value: uint = 0u - 1u;
+
+/* Function: add */
+pure fn add(x: uint, y: uint) -> uint { ret x + y; }
+
+/* Function: sub */
+pure fn sub(x: uint, y: uint) -> uint { ret x - y; }
+
+/* Function: mul */
+pure fn mul(x: uint, y: uint) -> uint { ret x * y; }
+
+/* Function: div */
+pure fn div(x: uint, y: uint) -> uint { ret x / y; }
+
+/* Function: div_ceil
+
+   Divide two numbers, return the result, rounded up.
+
+   Parameters:
+   x - an integer
+   y - an integer distinct from 0u
+
+   Return:
+    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; }
+}
+
+/* Function: div_ceil
+
+   Divide two numbers, return the result, rounded to the closest integer.
+
+   Parameters:
+   x - an integer
+   y - an integer distinct from 0u
+
+   Return:
+    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; }
+}
+
+/* Function: div_ceil
+
+   Divide two numbers, return the result, rounded down.
+
+   Parameters:
+   x - an integer
+   y - an integer distinct from 0u
+
+   Note: This is the same function as `div`.
+
+   Return:
+    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; }
+
+/* Function: rem */
+pure fn rem(x: uint, y: uint) -> uint { ret x % y; }
+
+/* Predicate: lt */
+pure fn lt(x: uint, y: uint) -> bool { ret x < y; }
+
+/* Predicate: le */
+pure fn le(x: uint, y: uint) -> bool { ret x <= y; }
+
+/* Predicate: eq */
+pure fn eq(x: uint, y: uint) -> bool { ret x == y; }
+
+/* Predicate: ne */
+pure fn ne(x: uint, y: uint) -> bool { ret x != y; }
+
+/* Predicate: ge */
+pure fn ge(x: uint, y: uint) -> bool { ret x >= y; }
+
+/* Predicate: gt */
+pure fn gt(x: uint, y: uint) -> bool { ret x > y; }
+
+/*
+Function: range
+
+Iterate over the range [`lo`..`hi`)
+*/
+fn range(lo: uint, hi: uint, it: block(uint)) {
+    let i = lo;
+    while i < hi { it(i); i += 1u; }
+}
+
+/*
+Function: loop
+
+Iterate over the range [`lo`..`hi`), or stop when requested
+
+Parameters:
+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.
+
+Returns:
+
+`true` If execution proceeded correctly, `false` if it was interrupted,
+that is if `it` returned `false` at any point.
+*/
+fn loop(lo: uint, hi: uint, it: block(uint) -> bool) -> bool {
+    let i = lo;
+    while i < hi {
+        if (!it(i)) { ret false; }
+        i += 1u;
+    }
+    ret true;
+}
+
+/*
+Function: next_power_of_two
+
+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 tmp: uint = n - 1u;
+    let shift: uint = 1u;
+    while shift <= halfbits { tmp |= tmp >> shift; shift <<= 1u; }
+    ret tmp + 1u;
+}
+
+/*
+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) -> uint {
+    if vec::len::<u8>(buf) == 0u {
+        log_err "parse_buf(): buf is empty";
+        fail;
+    }
+    let i = vec::len::<u8>(buf) - 1u;
+    let power = 1u;
+    let n = 0u;
+    while true {
+        let digit = char::to_digit(buf[i] as char);
+        if (digit as uint) >= radix {
+            fail;
+        }
+        n += (digit as uint) * power;
+        power *= radix;
+        if i == 0u { 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) -> uint { parse_buf(str::bytes(s), 10u) }
+
+/*
+Function: to_str
+
+Convert to a string in a given base
+*/
+fn to_str(num: uint, radix: uint) -> str {
+    let 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 s: str = "";
+    while n != 0u {
+        s += str::unsafe_from_byte(digit(n % radix) as u8);
+        n /= radix;
+    }
+    let s1: str = "";
+    let len: uint = str::byte_len(s);
+    while len != 0u { len -= 1u; s1 += str::unsafe_from_byte(s[len]); }
+    ret s1;
+}
+
+/*
+Function: str
+
+Convert to a string
+*/
+fn str(i: uint) -> str { ret to_str(i, 10u); }
+
+// Local Variables:
+// mode: rust;
+// fill-column: 78;
+// indent-tabs-mode: nil
+// c-basic-offset: 4
+// buffer-file-coding-system: utf-8-unix
+// End: