Implement dynamic dispatch for different number types

1 files changed, 513 insertions, 0 deletions

diff --git a/src/numbers/dynnum.rs b/src/numbers/dynnum.rs
new file mode 100644
index 0000000..eab11c6
--- /dev/null
+++ b/src/numbers/dynnum.rs
@@ -0,0 +1,513 @@
+/*  OpenTally: Open-source election vote counting
+ *  Copyright © 2021 Lee Yingtong Li (RunasSudo)
+ *
+ *  This program is free software: you can redistribute it and/or modify
+ *  it under the terms of the GNU Affero General Public License as published by
+ *  the Free Software Foundation, either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU Affero General Public License for more details.
+ *
+ *  You should have received a copy of the GNU Affero General Public License
+ *  along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+use super::{Assign, Fixed, GuardedFixed, NativeFloat64, Number, Rational};
+
+use num_traits::{Num, One, Zero};
+//use wasm_bindgen::prelude::wasm_bindgen;
+
+use std::cmp::{Ord, Ordering};
+use std::fmt;
+use std::mem::ManuallyDrop;
+use std::ops::{self, Deref, DerefMut};
+
+/// Represents the underlying implementation for [DynNum]s
+//#[wasm_bindgen]
+pub enum NumKind {
+	/// See [crate::numbers::fixed]
+	Fixed,
+	/// See [crate::numbers::gfixed]
+	GuardedFixed,
+	/// See [crate::numbers::native]
+	NativeFloat64,
+	/// See [crate::numbers::rational_rug] or [crate::numbers::rational_num]
+	Rational,
+}
+
+/// Determines which underlying implementation to use
+static mut KIND: NumKind = NumKind::Fixed;
+
+/// Returns which underlying implementation is in use
+#[inline]
+fn get_kind() -> &'static NumKind {
+	unsafe {
+		return &KIND;
+	}
+}
+
+/// A wrapper for different numeric types using dynamic dispatch
+pub union DynNum {
+	fixed: ManuallyDrop<Fixed>,
+	gfixed: ManuallyDrop<GuardedFixed>,
+	float64: NativeFloat64,
+	rational: ManuallyDrop<Rational>,
+}
+
+impl DynNum {
+	/// Set which underlying implementation to use
+	pub fn set_kind(kind: NumKind) {
+		unsafe {
+			KIND = kind;
+		}
+	}
+}
+
+macro_rules! impl_1arg_nowrap {
+	($self:expr, $arg:expr, $func:ident) => {
+		// Safety: Access only correct union field
+		unsafe {
+			match get_kind() {
+				NumKind::Fixed => {
+					$self.fixed.$func($arg)
+				}
+				NumKind::GuardedFixed => {
+					$self.gfixed.$func($arg)
+				}
+				NumKind::NativeFloat64 => {
+					$self.float64.$func($arg)
+				}
+				NumKind::Rational => {
+					$self.rational.$func($arg)
+				}
+			}
+		}
+	}
+}
+
+macro_rules! impl_assoc_nowrap {
+	($func:ident) => {
+		match get_kind() {
+			NumKind::Fixed => {
+				Fixed::$func()
+			}
+			NumKind::GuardedFixed => {
+				GuardedFixed::$func()
+			}
+			NumKind::NativeFloat64 => {
+				NativeFloat64::$func()
+			}
+			NumKind::Rational => {
+				Rational::$func()
+			}
+		}
+	}
+}
+
+impl Number for DynNum {
+	fn new() -> Self {
+		match get_kind() {
+			NumKind::Fixed => {
+				DynNum { fixed: ManuallyDrop::new(Fixed::new()) }
+			}
+			NumKind::GuardedFixed => {
+				DynNum { gfixed: ManuallyDrop::new(GuardedFixed::new()) }
+			}
+			NumKind::NativeFloat64 => {
+				DynNum { float64: NativeFloat64::new() }
+			}
+			NumKind::Rational => {
+				DynNum { rational: ManuallyDrop::new(Rational::new()) }
+			}
+		}
+	}
+	
+	fn describe() -> String { impl_assoc_nowrap!(describe) }
+	fn pow_assign(&mut self, exponent: i32) { impl_1arg_nowrap!(self, exponent, pow_assign) }
+	fn floor_mut(&mut self, dps: usize) { impl_1arg_nowrap!(self, dps, floor_mut) }
+	fn ceil_mut(&mut self, dps: usize) { impl_1arg_nowrap!(self, dps, ceil_mut) }
+	fn round_mut(&mut self, dps: usize) { impl_1arg_nowrap!(self, dps, round_mut) }
+}
+
+impl Drop for DynNum {
+	fn drop(&mut self) {
+		// Safety: Access only correct union field
+		unsafe {
+			match get_kind() {
+				NumKind::Fixed => {
+					ManuallyDrop::drop(&mut self.fixed);
+				}
+				NumKind::GuardedFixed => {
+					ManuallyDrop::drop(&mut self.gfixed);
+				}
+				NumKind::NativeFloat64 => {}
+				NumKind::Rational => {
+					ManuallyDrop::drop(&mut self.rational);
+				}
+			}
+		}
+	}
+}
+
+macro_rules! impl_0arg_wrap {
+	($self:expr, $func:ident) => {
+		// Safety: Access only correct union field
+		unsafe {
+			match get_kind() {
+				NumKind::Fixed => {
+					DynNum { fixed: ManuallyDrop::new($self.fixed.deref().$func()) }
+				}
+				NumKind::GuardedFixed => {
+					DynNum { gfixed: ManuallyDrop::new($self.gfixed.deref().$func()) }
+				}
+				NumKind::NativeFloat64 => {
+					DynNum { float64: $self.float64.$func() }
+				}
+				NumKind::Rational => {
+					DynNum { rational: ManuallyDrop::new($self.rational.deref().$func()) }
+				}
+			}
+		}
+	}
+}
+
+impl Clone for DynNum {
+	fn clone(&self) -> Self { impl_0arg_wrap!(self, clone) }
+}
+
+impl Num for DynNum {
+	type FromStrRadixErr = Self; // TODO
+	
+	fn from_str_radix(str: &str, radix: u32) -> Result<Self, Self::FromStrRadixErr> {
+		match get_kind() {
+			NumKind::Fixed => {
+				Ok(DynNum { fixed: ManuallyDrop::new(Fixed::from_str_radix(str, radix).unwrap()) })
+			}
+			NumKind::GuardedFixed => {
+				Ok(DynNum { gfixed: ManuallyDrop::new(GuardedFixed::from_str_radix(str, radix).unwrap()) })
+			}
+			NumKind::NativeFloat64 => {
+				Ok(DynNum { float64: NativeFloat64::from_str_radix(str, radix).unwrap() })
+			}
+			NumKind::Rational => {
+				Ok(DynNum { rational: ManuallyDrop::new(Rational::from_str_radix(str, radix).unwrap()) })
+			}
+		}
+	}
+}
+
+macro_rules! impl_1other_nowrap {
+	($self:expr, $rhs:expr, $func:ident) => {
+		// Safety: Access only correct union field
+		unsafe {
+			match get_kind() {
+				NumKind::Fixed => {
+					$self.fixed.deref().$func($rhs.fixed.deref())
+				}
+				NumKind::GuardedFixed => {
+					$self.gfixed.deref().$func($rhs.gfixed.deref())
+				}
+				NumKind::NativeFloat64 => {
+					$self.float64.$func(&$rhs.float64)
+				}
+				NumKind::Rational => {
+					$self.rational.deref().$func($rhs.rational.deref())
+				}
+			}
+		}
+	}
+}
+
+macro_rules! impl_1other_nowrap_mut {
+	($self:expr, $rhs:expr, $func:ident) => {
+		// Safety: Access only correct union field
+		unsafe {
+			match get_kind() {
+				NumKind::Fixed => {
+					$self.fixed.deref_mut().$func($rhs.fixed.deref())
+				}
+				NumKind::GuardedFixed => {
+					$self.gfixed.deref_mut().$func($rhs.gfixed.deref())
+				}
+				NumKind::NativeFloat64 => {
+					$self.float64.$func(&$rhs.float64)
+				}
+				NumKind::Rational => {
+					$self.rational.deref_mut().$func($rhs.rational.deref())
+				}
+			}
+		}
+	}
+}
+
+impl Assign for DynNum {
+	fn assign(&mut self, src: Self) { impl_1other_nowrap_mut!(self, src, assign) }
+}
+
+impl Assign<&Self> for DynNum {
+	fn assign(&mut self, src: &Self) { impl_1other_nowrap_mut!(self, src, assign) }
+}
+
+impl From<usize> for DynNum {
+	fn from(n: usize) -> Self {
+		match get_kind() {
+			NumKind::Fixed => {
+				DynNum { fixed: ManuallyDrop::new(Fixed::from(n)) }
+			}
+			NumKind::GuardedFixed => {
+				DynNum { gfixed: ManuallyDrop::new(GuardedFixed::from(n)) }
+			}
+			NumKind::NativeFloat64 => {
+				DynNum { float64: NativeFloat64::from(n) }
+			}
+			NumKind::Rational => {
+				DynNum { rational: ManuallyDrop::new(Rational::from(n)) }
+			}
+		}
+	}
+}
+
+impl fmt::Display for DynNum {
+	fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { impl_1arg_nowrap!(self, f, fmt) }
+}
+
+impl fmt::Debug for DynNum {
+	fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { impl_1arg_nowrap!(self, f, fmt) }
+}
+
+impl PartialEq for DynNum {
+	fn eq(&self, other: &Self) -> bool { impl_1other_nowrap!(self, other, eq) }
+}
+
+impl Eq for DynNum {}
+
+impl PartialOrd for DynNum {
+	fn partial_cmp(&self, other: &Self) -> Option<Ordering> { impl_1other_nowrap!(self, other, partial_cmp) }
+}
+
+impl Ord for DynNum {
+	fn cmp(&self, other: &Self) -> Ordering { impl_1other_nowrap!(self, other, cmp) }
+}
+
+macro_rules! impl_assoc_wrap {
+	($func:ident) => {
+		match get_kind() {
+			NumKind::Fixed => {
+				DynNum { fixed: ManuallyDrop::new(Fixed::$func()) }
+			}
+			NumKind::GuardedFixed => {
+				DynNum { gfixed: ManuallyDrop::new(GuardedFixed::$func()) }
+				}
+			NumKind::NativeFloat64 => {
+				DynNum { float64: NativeFloat64::$func() }
+			}
+			NumKind::Rational => {
+				DynNum { rational: ManuallyDrop::new(Rational::$func()) }
+			}
+		}
+	}
+}
+
+impl One for DynNum {
+	fn one() -> Self { impl_assoc_wrap!(one) }
+}
+
+macro_rules! impl_0arg_nowrap {
+	($self:expr, $func:ident) => {
+		// Safety: Access only correct union field
+		unsafe {
+			match get_kind() {
+				NumKind::Fixed => {
+					$self.fixed.deref().$func()
+				}
+				NumKind::GuardedFixed => {
+					$self.gfixed.deref().$func()
+				}
+				NumKind::NativeFloat64 => {
+					$self.float64.$func()
+				}
+				NumKind::Rational => {
+					$self.rational.deref().$func()
+				}
+			}
+		}
+	}
+}
+
+impl Zero for DynNum {
+	fn zero() -> Self { impl_assoc_wrap!(zero) }
+	
+	fn is_zero(&self) -> bool { impl_0arg_nowrap!(self, is_zero) }
+}
+
+impl ops::Neg for DynNum {
+	type Output = Self;
+	fn neg(self) -> Self::Output { impl_0arg_wrap!(self, neg) }
+}
+
+macro_rules! impl_1other_wrap {
+	($self:expr, $rhs:expr, $func:ident) => {
+		// Safety: Access only correct union field
+		unsafe {
+			match get_kind() {
+				NumKind::Fixed => {
+					DynNum { fixed: ManuallyDrop::new($self.fixed.deref().$func($rhs.fixed.deref())) }
+				}
+				NumKind::GuardedFixed => {
+					DynNum { gfixed: ManuallyDrop::new($self.gfixed.deref().$func($rhs.gfixed.deref())) }
+				}
+				NumKind::NativeFloat64 => {
+					DynNum { float64: $self.float64.$func($rhs.float64) }
+				}
+				NumKind::Rational => {
+					DynNum { rational: ManuallyDrop::new($self.rational.deref().$func($rhs.rational.deref())) }
+				}
+			}
+		}
+	}
+}
+
+impl ops::Add for DynNum {
+	type Output = Self;
+	fn add(self, rhs: Self) -> Self::Output { impl_1other_wrap!(self, rhs, add) }
+}
+
+impl ops::Sub for DynNum {
+	type Output = Self;
+	fn sub(self, rhs: Self) -> Self::Output { impl_1other_wrap!(self, rhs, sub) }
+}
+
+impl ops::Mul for DynNum {
+	type Output = Self;
+	fn mul(self, rhs: Self) -> Self::Output { impl_1other_wrap!(self, rhs, mul) }
+}
+
+impl ops::Div for DynNum {
+	type Output = Self;
+	fn div(self, rhs: Self) -> Self::Output { impl_1other_wrap!(self, rhs, div) }
+}
+
+impl ops::Rem for DynNum {
+	type Output = Self;
+	fn rem(self, rhs: Self) -> Self::Output { impl_1other_wrap!(self, rhs, rem) }
+}
+
+impl ops::Add<&Self> for DynNum {
+	type Output = Self;
+	fn add(self, rhs: &Self) -> Self::Output { impl_1other_wrap!(self, rhs, add) }
+}
+
+impl ops::Sub<&Self> for DynNum {
+	type Output = Self;
+	fn sub(self, rhs: &Self) -> Self::Output { impl_1other_wrap!(self, rhs, sub) }
+}
+
+impl ops::Mul<&Self> for DynNum {
+	type Output = Self;
+	fn mul(self, rhs: &Self) -> Self::Output { impl_1other_wrap!(self, rhs, mul) }
+}
+
+impl ops::Div<&Self> for DynNum {
+	type Output = Self;
+	fn div(self, rhs: &Self) -> Self::Output { impl_1other_wrap!(self, rhs, div) }
+}
+
+impl ops::Rem<&Self> for DynNum {
+	type Output = Self;
+	fn rem(self, rhs: &Self) -> Self::Output { impl_1other_wrap!(self, rhs, rem) }
+}
+
+impl ops::AddAssign for DynNum {
+	fn add_assign(&mut self, rhs: Self) { impl_1other_nowrap_mut!(self, rhs, add_assign) }
+}
+
+impl ops::SubAssign for DynNum {
+	fn sub_assign(&mut self, rhs: Self) { impl_1other_nowrap_mut!(self, rhs, sub_assign) }
+}
+
+impl ops::MulAssign for DynNum {
+	fn mul_assign(&mut self, rhs: Self) { impl_1other_nowrap_mut!(self, rhs, mul_assign) }
+}
+
+impl ops::DivAssign for DynNum {
+	fn div_assign(&mut self, rhs: Self) { impl_1other_nowrap_mut!(self, rhs, div_assign) }
+}
+
+impl ops::RemAssign for DynNum {
+	fn rem_assign(&mut self, rhs: Self) { impl_1other_nowrap_mut!(self, rhs, rem_assign) }
+}
+
+impl ops::AddAssign<&Self> for DynNum {
+	fn add_assign(&mut self, rhs: &Self) { impl_1other_nowrap_mut!(self, rhs, add_assign) }
+}
+
+impl ops::SubAssign<&Self> for DynNum {
+	fn sub_assign(&mut self, rhs: &Self) { impl_1other_nowrap_mut!(self, rhs, sub_assign) }
+}
+
+impl ops::MulAssign<&Self> for DynNum {
+	fn mul_assign(&mut self, rhs: &Self) { impl_1other_nowrap_mut!(self, rhs, mul_assign) }
+}
+
+impl ops::DivAssign<&Self> for DynNum {
+	fn div_assign(&mut self, rhs: &Self) { impl_1other_nowrap_mut!(self, rhs, div_assign) }
+}
+
+impl ops::RemAssign<&Self> for DynNum {
+	fn rem_assign(&mut self, rhs: &Self) { impl_1other_nowrap_mut!(self, rhs, rem_assign) }
+}
+
+impl ops::Neg for &DynNum {
+	type Output = DynNum;
+	fn neg(self) -> Self::Output { impl_0arg_wrap!(self, neg) }
+}
+
+impl ops::Add<Self> for &DynNum {
+	type Output = DynNum;
+	fn add(self, rhs: Self) -> Self::Output { impl_1other_wrap!(self, rhs, add) }
+}
+
+impl ops::Sub<Self> for &DynNum {
+	type Output = DynNum;
+	fn sub(self, rhs: Self) -> Self::Output { impl_1other_wrap!(self, rhs, sub) }
+}
+
+impl ops::Mul<Self> for &DynNum {
+	type Output = DynNum;
+	fn mul(self, rhs: Self) -> Self::Output { impl_1other_wrap!(self, rhs, mul) }
+}
+
+impl ops::Div<Self> for &DynNum {
+	type Output = DynNum;
+	fn div(self, rhs: Self) -> Self::Output { impl_1other_wrap!(self, rhs, div) }
+}
+
+impl ops::Rem<Self> for &DynNum {
+	type Output = DynNum;
+	fn rem(self, rhs: Self) -> Self::Output { impl_1other_wrap!(self, rhs, rem) }
+}
+
+/*
+impl ops::Add<&&Rational> for &Rational {
+	
+}
+
+impl ops::Sub<&&Rational> for &Rational {
+	
+}
+
+impl ops::Mul<&&Rational> for &Rational {
+	
+}
+
+impl ops::Div<&&Rational> for &Rational {
+	
+}
+
+impl ops::Rem<&&Rational> for &Rational {
+	
+}
+*/