1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220
#[cfg(feature = "decimal")]
use decimal::d128;
use num::Zero;
use num_complex::Complex;
/// Nested sets and conversions between them (using an injective mapping). Useful to work with
/// substructures. In generic code, it is preferable to use `SupersetOf` as trait bound whenever
/// possible instead of `SubsetOf` (because SupersetOf is automatically implemented whenever
/// `SubsetOf` is).
///
/// The notion of "nested sets" is very broad and applies to what the types are _supposed to
/// represent_, independently from their actual implementation details and limitations. For
/// example:
/// * f32 and f64 are both supposed to represent reals and are thus considered equal (even if in
/// practice f64 has more elements).
/// * u32 and i8 are respectively supposed to represent natural and relative numbers. Thus, u32 is
/// a subset of i8.
/// * A quaternion and a 3x3 orthogonal matrix with unit determinant are both sets of rotations.
/// They can thus be considered equal.
///
/// In other words, implementation details due to machine limitations are ignored (otherwise we
/// could not even, e.g., convert a u64 to an i64). If considering those limitations are
/// important, other crates allowing you to query the limitations of given types should be used.
pub trait SubsetOf<T>: Sized {
/// The inclusion map: converts `self` to the equivalent element of its superset.
fn to_superset(&self) -> T;
/// The inverse inclusion map: attempts to construct `self` from the equivalent element of its
/// superset.
///
/// Must return `None` if `element` has no equivalent in `Self`.
fn from_superset(element: &T) -> Option<Self> {
if Self::is_in_subset(element) {
Some(Self::from_superset_unchecked(element))
} else {
None
}
}
/// Use with care! Same as `self.to_superset` but without any property checks. Always succeeds.
fn from_superset_unchecked(element: &T) -> Self;
/// Checks if `element` is actually part of the subset `Self` (and can be converted to it).
fn is_in_subset(element: &T) -> bool;
}
/// Nested sets and conversions between them. Useful to work with substructures. It is preferable
/// to implement the `SubsetOf` trait instead of `SupersetOf` whenever possible (because
/// `SupersetOf` is automatically implemented whenever `SubsetOf` is).
///
/// The notion of "nested sets" is very broad and applies to what the types are _supposed to
/// represent_, independently from their actual implementation details and limitations. For
/// example:
/// * f32 and f64 are both supposed to represent reals and are thus considered equal (even if in
/// practice f64 has more elements).
/// * u32 and i8 are respectively supposed to represent natural and relative numbers. Thus, i8 is
/// a superset of u32.
/// * A quaternion and a 3x3 orthogonal matrix with unit determinant are both sets of rotations.
/// They can thus be considered equal.
///
/// In other words, implementation details due to machine limitations are ignored (otherwise we
/// could not even, e.g., convert a u64 to an i64). If considering those limitations are
/// important, other crates allowing you to query the limitations of given types should be used.
pub trait SupersetOf<T>: Sized {
/// The inverse inclusion map: attempts to construct `self` from the equivalent element of its
/// superset.
///
/// Must return `None` if `element` has no equivalent in `Self`.
fn to_subset(&self) -> Option<T> {
if self.is_in_subset() {
Some(self.to_subset_unchecked())
} else {
None
}
}
/// Checks if `self` is actually part of its subset `T` (and can be converted to it).
fn is_in_subset(&self) -> bool;
/// Use with care! Same as `self.to_subset` but without any property checks. Always succeeds.
fn to_subset_unchecked(&self) -> T;
/// The inclusion map: converts `self` to the equivalent element of its superset.
fn from_subset(element: &T) -> Self;
}
impl<SS: SubsetOf<SP>, SP> SupersetOf<SS> for SP {
#[inline]
fn to_subset(&self) -> Option<SS> {
SS::from_superset(self)
}
#[inline]
fn is_in_subset(&self) -> bool {
SS::is_in_subset(self)
}
#[inline]
fn to_subset_unchecked(&self) -> SS {
SS::from_superset_unchecked(self)
}
#[inline]
fn from_subset(element: &SS) -> Self {
element.to_superset()
}
}
macro_rules! impl_subset (
($($subset: ty as $( $superset: ty),+ );* $(;)*) => {
$($(
impl SubsetOf<$superset> for $subset {
#[inline]
fn to_superset(&self) -> $superset {
*self as $superset
}
#[inline]
fn from_superset_unchecked(element: &$superset) -> $subset {
*element as $subset
}
#[inline]
fn is_in_subset(_: &$superset) -> bool {
true
}
}
)+)*
}
);
impl_subset!(
u8 as u8, u16, u32, u64, u128, usize, i8, i16, i32, i64, i128, isize, f32, f64;
u16 as u8, u16, u32, u64, u128, usize, i8, i16, i32, i64, i128, isize, f32, f64;
u32 as u8, u16, u32, u64, u128, usize, i8, i16, i32, i64, i128, isize, f32, f64;
u64 as u8, u16, u32, u64, u128, usize, i8, i16, i32, i64, i128, isize, f32, f64;
u128 as u8, u16, u32, u64, u128, usize, i8, i16, i32, i64, i128, isize, f32, f64;
usize as u8, u16, u32, u64, u128, usize, i8, i16, i32, i64, i128, isize, f32, f64;
i8 as i8, i16, i32, i64, i128, isize, f32, f64;
i16 as i8, i16, i32, i64, i128, isize, f32, f64;
i32 as i8, i16, i32, i64, i128, isize, f32, f64;
i64 as i8, i16, i32, i64, i128, isize, f32, f64;
i128 as i8, i16, i32, i64, i128, isize, f32, f64;
isize as i8, i16, i32, i64, i128, isize, f32, f64;
f32 as f32, f64;
f64 as f32, f64;
);
//#[cfg(feature = "decimal")]
//impl_subset!(
// u8 as d128;
// u16 as d128;
// u32 as d128;
// u64 as d128;
// usize as d128;
//
// i8 as d128;
// i16 as d128;
// i32 as d128;
// i64 as d128;
// isize as d128;
//
// f32 as d128;
// f64 as d128;
// d128 as d128;
//);
impl<N1, N2: SupersetOf<N1>> SubsetOf<Complex<N2>> for Complex<N1> {
#[inline]
fn to_superset(&self) -> Complex<N2> {
Complex {
re: N2::from_subset(&self.re),
im: N2::from_subset(&self.im),
}
}
#[inline]
fn from_superset_unchecked(element: &Complex<N2>) -> Complex<N1> {
Complex {
re: element.re.to_subset_unchecked(),
im: element.im.to_subset_unchecked(),
}
}
#[inline]
fn is_in_subset(c: &Complex<N2>) -> bool {
c.re.is_in_subset() && c.im.is_in_subset()
}
}
macro_rules! impl_scalar_subset_of_complex (
($($t: ident),*) => {$(
impl<N2: Zero + SupersetOf<$t>> SubsetOf<Complex<N2>> for $t {
#[inline]
fn to_superset(&self) -> Complex<N2> {
Complex {
re: N2::from_subset(self),
im: N2::zero()
}
}
#[inline]
fn from_superset_unchecked(element: &Complex<N2>) -> $t {
element.re.to_subset_unchecked()
}
#[inline]
fn is_in_subset(c: &Complex<N2>) -> bool {
c.re.is_in_subset() && c.im.is_zero()
}
}
)*}
);
impl_scalar_subset_of_complex!(
u8, u16, u32, u64, u128, usize, i8, i16, i32, i64, i128, isize, f32, f64
);
#[cfg(feature = "decimal")]
impl_scalar_subset_of_complex!(d128);