Messy work in progress

This commit is contained in:
Timothy Warren 2020-02-14 17:24:51 -05:00
parent d20cb06c87
commit fb87807227
2 changed files with 182 additions and 18 deletions

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@ -1,4 +1,5 @@
//! Numeric Helper Traits //! Numeric Helper Traits
use std::convert::TryFrom;
use std::ops::{ use std::ops::{
Add, AddAssign, BitAnd, BitAndAssign, BitOr, BitOrAssign, BitXor, BitXorAssign, Div, DivAssign, Add, AddAssign, BitAnd, BitAndAssign, BitOr, BitOrAssign, BitXor, BitXorAssign, Div, DivAssign,
Mul, MulAssign, Not, Rem, RemAssign, Shl, ShlAssign, Shr, ShrAssign, Sub, SubAssign, Mul, MulAssign, Not, Rem, RemAssign, Shl, ShlAssign, Shr, ShrAssign, Sub, SubAssign,
@ -41,6 +42,15 @@ pub trait Unsigned: Int {
/// Find the least common multiple of two numbers /// Find the least common multiple of two numbers
fn lcm(a: Self, b: Self) -> Self; fn lcm(a: Self, b: Self) -> Self;
fn is_signed(self) -> bool;
}
/// A Trait representing signed integer primitives
pub trait Signed<U=Unsigned>: Int {
fn is_neg(self) -> bool;
fn to_unsigned<U>(self) -> U;
} }
#[derive(Debug, Copy, Clone, PartialEq, Eq)] #[derive(Debug, Copy, Clone, PartialEq, Eq)]
@ -143,9 +153,29 @@ macro_rules! impl_unsigned {
}; };
} }
impl_num!(i8, u8, i16, u16, f32, i32, u32, f64, i64, u64, i128, u128, usize); macro_rules! impl_signed {
impl_int!(i8, u8, i16, u16, i32, u32, i64, u64, i128, u128, usize); ($(($type: ty, $un_type: ty)),* ) => {
$(
impl Signed<U=$un_type> for $type {
fn is_neg(self) -> bool {
self < 0
}
fn to_unsigned<U>(self) -> U {
// Converting from signed to unsigned should always be safe
// when using the absolute value, especially since I'm converting
// between the same bit size
<U>::try_from(self).unwrap()
}
}
)*
}
}
impl_num!(i8, u8, i16, u16, f32, i32, u32, f64, i64, u64, i128, u128, isize, usize);
impl_int!(i8, u8, i16, u16, i32, u32, i64, u64, i128, u128, isize, usize);
impl_unsigned!(u8, u16, u32, u64, u128, usize); impl_unsigned!(u8, u16, u32, u64, u128, usize);
impl_signed!((i8,u8),(i16,u16),(i32,u32),(i64,u64),(i128,u128),(isize,usize));
#[cfg(test)] #[cfg(test)]
mod tests { mod tests {

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@ -12,18 +12,78 @@
//! * SubAssign //! * SubAssign
use crate::num::*; use crate::num::*;
use std::ops::{Mul, Neg}; use std::ops::{Add, Div, Mul, Neg, Sub};
#[derive(Debug, Default, Copy, Clone, Eq, PartialEq)] #[derive(Debug, Copy, Clone, Eq, PartialEq)]
pub struct Frac<T: Unsigned = usize> { pub struct Frac<T: Unsigned = usize> {
numer: T, numer: T,
denom: T, denom: T,
sign: Sign, sign: Sign,
} }
#[macro_export]
macro_rules! frac {
($n:literal / $d:literal) => {
Frac::new_conv($n, $d)
};
}
/* macro_rules! impl_from_signed {
($(($in_type: ty, $out_type: ty)),* ) => {
$(
impl Frac<$in_type> {
pub fn new(n: $in_type, d: $in_type) -> Frac<$out_type> {
// Converting from signed to unsigned should always be safe
// when using the absolute value, especially since I'm converting
// between the same bit size
let mut sign = $crate::num::Sign::Positive;
let numer = <$out_type>::try_from(n.abs()).unwrap();
let denom = <$out_type>::try_from(d.abs()).unwrap();
if n < 0 {
sign = !sign;
}
if d < 0 {
sign = !sign;
}
Frac::new_signed(numer, denom, sign)
}
fn new_signed(n: $in_type, d: $in_type, _: $crate::num::Sign) -> Frac<$out_type> {
Self::new(n, d)
}
}
)*
};
}
impl_from_signed!((i8, u8), (i16, u16), (i32, u32), (i64, u64), (i128, u128), (isize, usize)); */
impl<T: Signed, U: Unsigned> Frac<U> {
pub fn new_conv(n: T, d: T) -> Self {
// Converting from signed to unsigned should always be safe
// when using the absolute value, especially since I'm converting
// between the same bit size
let mut sign = Sign::Positive;
let numer:T::Un = n.to_unsigned();
let denom:T::Un = d.to_unsigned();
if n.is_neg() {
sign = !sign;
}
if d.is_neg() {
sign = !sign;
}
Self::new(numer, denom, sign)
}
}
impl<T: Unsigned> Frac<T> { impl<T: Unsigned> Frac<T> {
/// Create a new rational number /// Create a new rational number
pub fn new(n: T, d: T) -> Self { pub fn new(n: T, d: T, s: Sign) -> Self {
if d.is_zero() { if d.is_zero() {
panic!("Fraction can not have a zero denominator"); panic!("Fraction can not have a zero denominator");
} }
@ -31,18 +91,21 @@ impl<T: Unsigned> Frac<T> {
Frac { Frac {
numer: n, numer: n,
denom: d, denom: d,
sign: Sign::Positive, sign: s,
} }
.reduce() .reduce()
} }
pub fn new_neg(n: T, d: T) -> Self { /// Determine the output sign given the two input signs
let mut frac = Frac::new(n, d); fn get_sign(a: Self, b: Self) -> Sign {
frac.sign = Sign::Negative; if a.sign != b.sign {
Sign::Negative
frac } else {
Sign::Positive
}
} }
/// Convert the fraction to its simplest form
fn reduce(mut self) -> Self { fn reduce(mut self) -> Self {
let gcd = T::gcd(self.numer, self.denom); let gcd = T::gcd(self.numer, self.denom);
self.numer /= gcd; self.numer /= gcd;
@ -58,14 +121,69 @@ impl<T: Unsigned + Mul<Output = T>> Mul for Frac<T> {
fn mul(self, rhs: Self) -> Self { fn mul(self, rhs: Self) -> Self {
let numer = self.numer * rhs.numer; let numer = self.numer * rhs.numer;
let denom = self.denom * rhs.denom; let denom = self.denom * rhs.denom;
let sign = Self::get_sign(self, rhs);
// Figure out the sign Self::new_signed(numer, denom, sign)
if self.sign != rhs.sign {
Self::new_neg(numer, denom)
} else {
Self::new(numer, denom)
} }
} }
impl<T: Unsigned + Mul<Output = T>> Div for Frac<T> {
type Output = Self;
fn div(self, rhs: Self) -> Self {
let numer = self.numer * rhs.denom;
let denom = self.denom * rhs.numer;
let sign = Self::get_sign(self, rhs);
Self::new_signed(numer, denom, sign)
}
}
impl<T: Unsigned + Add<Output = T> + Sub<Output = T> + Mul<Output = T>> Add for Frac<T> {
type Output = Self;
fn add(self, rhs: Self) -> Self::Output {
let a = self;
let b = rhs;
// If the sign of one input differs,
// subtraction is equivalent
if self.sign != rhs.sign {
if a.numer > b.numer {
return a - b
} else if a.numer < b.numer {
return b - a
}
}
// Find a common denominator if needed
if a.denom != b.denom {
// Let's just use the simplest method, rather than
// worrying about reducing to the least common denominator
let numer = (a.numer * b.denom) + (b.numer * a.denom);
let denom = a.denom * b.denom;
let sign = Self::get_sign(a, b);
return Self::new_signed(numer, denom, sign);
}
let numer = a.numer + b.numer;
let denom = self.denom;
let sign = Self::get_sign(a, b);
Self::new_signed(numer, denom, sign)
}
}
impl<T: Unsigned + Sub<Output = T>> Sub for Frac<T> {
type Output = Self;
fn sub(self, rhs: Self) -> Self::Output {
let a = self;
let b = rhs;
unimplemented!()
}
} }
impl<T: Unsigned> Neg for Frac<T> { impl<T: Unsigned> Neg for Frac<T> {
@ -85,11 +203,27 @@ mod tests {
#[test] #[test]
fn mul_test() { fn mul_test() {
let frac1 = Frac::new(1u8, 3u8); let frac1 = Frac::new(1u8, 3u8, Sign::Positive);
let frac2 = Frac::new(2u8, 3u8); let frac2 = Frac::new(2u8, 3u8, Sign::Positive);
let expected = Frac::new(2u8, 9u8); let expected = Frac::new(2u8, 9u8, Sign::Positive);
assert_eq!(frac1 * frac2, expected); assert_eq!(frac1 * frac2, expected);
} }
#[test]
fn add_test() {
assert_eq!(frac!(5u8 / 6), frac!(1 / 3) + frac!(1 / 2));
}
#[test]
fn macro_test() {
let frac1 = frac!(1u8 / 3);
let frac2 = Frac::new(1u8, 3, Sign::Positive);
assert_eq!(frac1, frac2);
let frac1 = -frac!(1u8 / 2);
let frac2 = Frac::new(1u8, 2, Sign::Negative);
assert_eq!(frac1, frac2);
}
} }