use list_fn::{FlatMap, FlatMapFn, FlatMapList, ListFn, ListSome, ListState, ResultFn};
use std::marker::PhantomData;
use uints::UInt;
#[derive(Clone, Copy, Debug, PartialEq, Default)]
pub struct BitVec<T: UInt> {
pub array: T,
pub size: u8,
}
impl<T: UInt> BitVec<T> {
pub fn new_full(array: T) -> Self {
Self::new(array, T::BITS)
}
pub fn new(array: T, size: u8) -> Self {
BitVec { array, size }
}
pub fn concat(self, v: Self) -> Self {
BitVec {
array: self.array | (v.array << self.size),
size: self.size + v.size,
}
}
}
impl<T: UInt> ListFn for BitVec<T> {
type Item = bool;
type End = ();
fn next(self) -> ListState<Self> {
match self.size {
0 => ListState::End(()),
size => ListState::Some(ListSome {
first: self.array & T::ONE != T::ZERO,
next: BitVec {
array: self.array >> 1,
size: size - 1,
},
}),
}
}
}
pub struct Lsb0FlatMap<T: UInt>(PhantomData<T>);
impl<T: UInt> Default for Lsb0FlatMap<T> {
fn default() -> Self {
Self(Default::default())
}
}
impl<T: UInt> FlatMapFn for Lsb0FlatMap<T> {
type Input = T;
type OutputList = BitVec<T>;
fn map(&self, item: T) -> BitVec<T> {
BitVec::new_full(item)
}
}
pub trait Lsb0
where
Self: ListFn,
Self::Item: UInt,
Self::End: ResultFn<Result = ()>,
{
fn lsb0(self) -> FlatMapList<Self, Lsb0FlatMap<Self::Item>> {
self.flat_map(Lsb0FlatMap::default())
}
}
impl<L> Lsb0 for L
where
Self: ListFn,
Self::Item: UInt,
Self::End: ResultFn<Result = ()>,
{
}
#[cfg(test)]
mod tests {
use super::*;
use list_fn::{Collect, IterWrap};
#[test]
fn it_works() {
let a: &[u8] = &[1, 2];
assert_eq!(
a.iter().cloned().lsb0().collect().items,
vec!(
true, false, false, false, false, false, false, false, false, true, false, false,
false, false, false, false
)
);
let v: Vec<u8> = vec![3, 4];
assert_eq!(
v.into_iter().lsb0().collect().items,
vec!(
true, true, false, false, false, false, false, false, false, false, true, false,
false, false, false, false
)
);
{
let mut r = Vec::new();
let v: Vec<u8> = vec![3, 4];
for elem in v.into_iter().lsb0().iter_wrap() {
r.push(elem)
}
assert_eq!(
r,
vec!(
true, true, false, false, false, false, false, false, false, false, true,
false, false, false, false, false
)
);
}
}
}