libstd: Rational
requires Integer
as type bounds instead of Num
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e3695468b7
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@ -30,7 +30,7 @@ pub type Rational64 = Ratio<i64>;
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/// Alias for arbitrary precision rationals.
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pub type BigRational = Ratio<BigInt>;
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impl<T: Copy + Num + Ord>
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impl<T: Copy + Integer + Ord>
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Ratio<T> {
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/// Create a ratio representing the integer `t`.
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#[inline(always)]
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@ -57,7 +57,7 @@ impl<T: Copy + Num + Ord>
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/// Put self into lowest terms, with denom > 0.
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fn reduce(&mut self) {
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let g : T = gcd(self.numer, self.denom);
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let g : T = self.numer.gcd(&self.denom);
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self.numer /= g;
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self.denom /= g;
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@ -76,34 +76,6 @@ impl<T: Copy + Num + Ord>
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}
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}
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/**
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Compute the greatest common divisor of two numbers, via Euclid's algorithm.
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The result can be negative.
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*/
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#[inline]
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pub fn gcd_raw<T: Num>(n: T, m: T) -> T {
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let mut m = m, n = n;
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while m != Zero::zero() {
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let temp = m;
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m = n % temp;
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n = temp;
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}
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n
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}
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/**
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Compute the greatest common divisor of two numbers, via Euclid's algorithm.
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The result is always positive.
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*/
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#[inline]
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pub fn gcd<T: Num + Ord>(n: T, m: T) -> T {
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let g = gcd_raw(n, m);
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if g < Zero::zero() { -g }
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else { g }
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}
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/* Comparisons */
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// comparing a/b and c/d is the same as comparing a*d and b*c, so we
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@ -133,7 +105,7 @@ cmp_impl!(impl TotalOrd, cmp -> cmp::Ordering)
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/* Arithmetic */
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// a/b * c/d = (a*c)/(b*d)
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impl<T: Copy + Num + Ord>
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impl<T: Copy + Integer + Ord>
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Mul<Ratio<T>,Ratio<T>> for Ratio<T> {
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#[inline]
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fn mul(&self, rhs: &Ratio<T>) -> Ratio<T> {
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@ -142,7 +114,7 @@ impl<T: Copy + Num + Ord>
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}
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// (a/b) / (c/d) = (a*d)/(b*c)
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impl<T: Copy + Num + Ord>
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impl<T: Copy + Integer + Ord>
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Div<Ratio<T>,Ratio<T>> for Ratio<T> {
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#[inline]
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fn div(&self, rhs: &Ratio<T>) -> Ratio<T> {
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@ -153,7 +125,7 @@ impl<T: Copy + Num + Ord>
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// Abstracts the a/b `op` c/d = (a*d `op` b*d) / (b*d) pattern
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macro_rules! arith_impl {
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(impl $imp:ident, $method:ident) => {
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impl<T: Copy + Num + Ord>
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impl<T: Copy + Integer + Ord>
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$imp<Ratio<T>,Ratio<T>> for Ratio<T> {
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#[inline]
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fn $method(&self, rhs: &Ratio<T>) -> Ratio<T> {
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@ -173,16 +145,16 @@ arith_impl!(impl Sub, sub)
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// a/b % c/d = (a*d % b*c)/(b*d)
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arith_impl!(impl Rem, rem)
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impl<T: Copy + Num + Ord>
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impl<T: Copy + Integer + Ord>
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Neg<Ratio<T>> for Ratio<T> {
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#[inline]
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fn neg(&self) -> Ratio<T> {
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Ratio::new_raw(-self.numer, self.denom)
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Ratio::new_raw(-self.numer, self.denom.clone())
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}
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}
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/* Constants */
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impl<T: Copy + Num + Ord>
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impl<T: Copy + Integer + Ord>
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Zero for Ratio<T> {
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#[inline]
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fn zero() -> Ratio<T> {
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@ -195,7 +167,7 @@ impl<T: Copy + Num + Ord>
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}
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}
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impl<T: Copy + Num + Ord>
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impl<T: Copy + Integer + Ord>
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One for Ratio<T> {
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#[inline]
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fn one() -> Ratio<T> {
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@ -203,11 +175,11 @@ impl<T: Copy + Num + Ord>
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}
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}
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impl<T: Copy + Num + Ord>
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impl<T: Copy + Integer + Ord>
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Num for Ratio<T> {}
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/* Utils */
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impl<T: Copy + Num + Ord>
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impl<T: Copy + Integer + Ord>
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Round for Ratio<T> {
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fn floor(&self) -> Ratio<T> {
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@ -245,7 +217,7 @@ impl<T: Copy + Num + Ord>
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}
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}
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impl<T: Copy + Num + Ord> Fractional for Ratio<T> {
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impl<T: Copy + Integer + Ord> Fractional for Ratio<T> {
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#[inline]
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fn recip(&self) -> Ratio<T> {
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Ratio::new_raw(self.denom, self.numer)
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@ -266,7 +238,7 @@ impl<T: ToStrRadix> ToStrRadix for Ratio<T> {
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}
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}
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impl<T: FromStr + Copy + Num + Ord>
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impl<T: FromStr + Copy + Integer + Ord>
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FromStr for Ratio<T> {
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/// Parses `numer/denom`.
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fn from_str(s: &str) -> Option<Ratio<T>> {
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@ -283,7 +255,7 @@ impl<T: FromStr + Copy + Num + Ord>
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}
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}
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}
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impl<T: FromStrRadix + Copy + Num + Ord>
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impl<T: FromStrRadix + Copy + Integer + Ord>
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FromStrRadix for Ratio<T> {
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/// Parses `numer/denom` where the numbers are in base `radix`.
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fn from_str_radix(s: &str, radix: uint) -> Option<Ratio<T>> {
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@ -316,17 +288,6 @@ mod test {
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pub static _3_2: Rational = Ratio { numer: 3, denom: 2};
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pub static _neg1_2: Rational = Ratio { numer: -1, denom: 2};
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#[test]
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fn test_gcd() {
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assert_eq!(gcd(10,2),2);
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assert_eq!(gcd(10,3),1);
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assert_eq!(gcd(0,3),3);
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assert_eq!(gcd(3,3),3);
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assert_eq!(gcd(3,-3), 3);
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assert_eq!(gcd(-6,3), 3);
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assert_eq!(gcd(-4,-2), 2);
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}
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#[test]
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fn test_test_constants() {
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