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use super::*;
pub const EVEN_MASK_U8: u8 = 0b01010101;
pub const ODD_MASK_U8: u8 = EVEN_MASK_U8 << 1;
#[derive(Copy, Clone, Eq, PartialEq, Hash, IntoEnumIterator)]
pub enum L4 {
False = 0b10,
True = 0b01,
Unknown = 0b00,
Both = 0b11,
}
impl L4 {
#[inline]
pub const fn with_false(f: bool) -> L4 {
if f {
L4::False
} else {
L4::Unknown
}
}
#[inline]
pub const fn with_true(t: bool) -> L4 {
if t {
L4::True
} else {
L4::Unknown
}
}
#[inline]
pub const fn from_u8(x: u8) -> L4 {
use L4::*;
match x {
0b10 => False,
0b01 => True,
0b00 => Unknown,
_ => Both,
}
}
#[inline]
pub const fn from_bool(x: bool) -> L4 {
if x {
L4::True
} else {
L4::False
}
}
#[inline]
pub const fn from_opt(x: Option<bool>) -> L4 {
match x {
None => L4::Unknown,
Some(true) => L4::True,
Some(false) => L4::False,
}
}
#[inline]
pub const fn union(self, other: L4) -> L4 {
L4::from_u8(self as u8 | other as u8)
}
#[inline]
pub const fn intersection(self, other: L4) -> L4 {
L4::from_u8(self as u8 & other as u8)
}
#[inline]
pub const fn union_bool(self, other: bool) -> Option<bool> {
L4::from_u8(self as u8 | L4::from_bool(other) as u8).truth_value()
}
#[inline]
pub const fn intersection_bool(self, other: bool) -> Option<bool> {
L4::from_u8(self as u8 & L4::from_bool(other) as u8).truth_value()
}
#[inline]
pub const fn union_opt(self, other: Option<bool>) -> Option<bool> {
L4::from_u8(self as u8 | L4::from_opt(other) as u8).truth_value()
}
#[inline]
pub const fn intersection_opt(self, other: Option<bool>) -> Option<bool> {
L4::from_u8(self as u8 & L4::from_opt(other) as u8).truth_value()
}
#[inline]
pub const fn maybe_true(self) -> bool {
match self {
L4::False => false,
_ => true,
}
}
#[inline]
pub const fn maybe_false(self) -> bool {
match self {
L4::True => false,
_ => true,
}
}
#[inline]
pub const fn contains(self, b: bool) -> bool {
self as u8 & (1 << !b as u8) != 0
}
#[inline]
pub const fn truth_value(self) -> Option<bool> {
use L4::*;
match self {
False => Some(false),
True => Some(true),
_ => None,
}
}
#[inline]
pub const fn as_static(self) -> &'static L4 {
use L4::*;
match self {
False => &False,
True => &True,
Unknown => &Unknown,
Both => &Both,
}
}
#[inline]
pub const fn conjunction(self, other: L4) -> L4 {
L4::from_u8(self as u8 & ODD_MASK_U8 | other as u8 & ODD_MASK_U8 | self as u8 & other as u8)
}
#[inline]
pub const fn disjunction(self, other: L4) -> L4 {
L4::from_u8(
self as u8 & EVEN_MASK_U8 | other as u8 & EVEN_MASK_U8 | self as u8 & other as u8,
)
}
}
impl BitAnd for L4 {
type Output = L4;
#[inline]
fn bitand(self, rhs: Self) -> Self::Output {
self.conjunction(rhs)
}
}
impl BitOr for L4 {
type Output = L4;
#[inline]
fn bitor(self, rhs: Self) -> Self::Output {
self.disjunction(rhs)
}
}
impl Not for L4 {
type Output = L4;
fn not(self) -> Self::Output {
L4::from(((self as u8 & EVEN_MASK_U8) << 1) | ((self as u8 & ODD_MASK_U8) >> 1))
}
}
impl From<u8> for L4 {
#[inline]
fn from(x: u8) -> Self {
L4::from_u8(x)
}
}
impl From<bool> for L4 {
#[inline]
fn from(x: bool) -> Self {
L4::from_bool(x)
}
}
impl From<Option<bool>> for L4 {
#[inline]
fn from(x: Option<bool>) -> Self {
L4::from_opt(x)
}
}
impl Default for L4 {
#[inline]
fn default() -> Self {
L4::Unknown
}
}
impl Debug for L4 {
fn fmt(&self, f: &mut Formatter<'_>) -> fmt::Result {
let s = match self {
L4::False => "0",
L4::True => "1",
L4::Unknown => "Z",
L4::Both => "X",
};
Display::fmt(s, f)
}
}