succinct 0.5.2

Succinct data structures for Rust
Documentation 
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use std::ops::{Range, RangeTo, RangeFrom, RangeFull};

use bit_vec::traits::*;
use space_usage::SpaceUsage;
use storage::BlockType;

/// A borrowed slice of a bit vector.
#[derive(Clone, Copy, Debug)]
pub struct BitSlice<'a, Base: 'a + BitVec + ?Sized> {
    data: &'a Base,
    start: u64,
    len: u64,
}

/// A borrowed, mutable slice of a bit vector.
#[derive(Debug)]
pub struct BitSliceMut<'a, Base: 'a + BitVecMut + ?Sized> {
    data: &'a mut Base,
    start: u64,
    len: u64,
}

impl<'a, Base: 'a + BitVec + ?Sized> BitSlice<'a, Base> {
    /// Slices base to the specified range.
    pub fn new<R: IntoRange<u64>>(base: &'a Base, range: R) -> Self {
        let range = range.into_range(0, base.bit_len());
        assert!(range.end <= base.bit_len(), "BitSlice::new: out of bounds");
        BitSlice {
            data: base,
            start: range.start,
            len: range.end.saturating_sub(range.start),
        }
    }

    /// Slices this slice into a subslice.
    ///
    /// Unlike `BitSlice::new`, does not create an additional layer of
    /// indirection.
    pub fn slice<R: IntoRange<u64>>(&self, range: R) -> Self {
        let range = range.into_range(0, self.len);
        assert!(range.end <= self.len, "BitSlice::slice: out of bounds");
        BitSlice {
            data: self.data,
            start: self.start + range.start,
            len: range.end.saturating_sub(range.start),
        }
    }
}

impl<'a, Base: 'a + BitVecMut + ?Sized> BitSliceMut<'a, Base> {
    /// Slices base to the specified range.
    pub fn new<R: IntoRange<u64>>(base: &'a mut Base, range: R) -> Self {
        let range = range.into_range(0, base.bit_len());
        assert!(range.end <= base.bit_len(), "BitSlice::new: out of bounds");
        BitSliceMut {
            data: base,
            start: range.start,
            len: range.end.saturating_sub(range.start),
        }
    }

    /// Slices this slice into a mutable subslice.
    ///
    /// Unlike `BitSliceMut::new`, does not create an additional layer of
    /// indirection.
    pub fn slice_mut<R: IntoRange<u64>>(&mut self, range: R)
                                        -> BitSliceMut<Base> {
        let range = range.into_range(0, self.len);
        assert!(range.end <= self.len, "BitSlice::slice: out of bounds");
        BitSliceMut {
            data: self.data,
            start: self.start + range.start,
            len: range.end.saturating_sub(range.start),
        }
    }

    /// Slices this slice into an immutable subslice.
    pub fn slice<R: IntoRange<u64>>(&self, range: R) -> BitSlice<Base> {
        let range = range.into_range(0, self.len);
        assert!(range.end <= self.len, "BitSlice::slice: out of bounds");
        BitSlice {
            data: self.data,
            start: self.start + range.start,
            len: range.end.saturating_sub(range.start),
        }
    }
}

impl<'a, Base: 'a + BitVec + ?Sized> BitVec for BitSlice<'a, Base> {
    type Block = Base::Block;

    #[inline]
    fn bit_len(&self) -> u64 {
        self.len
    }

    #[inline]
    fn get_bit(&self, position: u64) -> bool {
        assert!(position < self.len, "BitSlice::get_bit: out of bounds");
        self.data.get_bit(self.start + position)
    }

    fn get_bits(&self, position: u64, count: usize) -> Self::Block {
        let end = position.checked_add(count as u64)
                          .expect("BitSlice::get_bits: index overflow");
        assert!(end <= self.len, "BitSlice::get_bits: out of bounds");
        self.data.get_bits(self.start + position, count)
    }

    fn get_block(&self, position: usize) -> Self::Block {
        self.get_bits(Self::Block::mul_nbits(position), Self::Block::nbits())
    }
}

impl<'a, Base: 'a + BitVecMut + ?Sized> BitVec for BitSliceMut<'a, Base> {
    type Block = Base::Block;

    #[inline]
    fn bit_len(&self) -> u64 {
        self.len
    }

    #[inline]
    fn get_bit(&self, position: u64) -> bool {
        assert!(position < self.len, "BitSlice::get_bit: out of bounds");
        self.data.get_bit(self.start + position)
    }

    fn get_bits(&self, position: u64, count: usize) -> Self::Block {
        let end = position.checked_add(count as u64)
                          .expect("BitSliceMut::get_bits: index overflow");
        assert!(end <= self.len, "BitSliceMut::get_bits: out of bounds");
        self.data.get_bits(self.start + position, count)
    }

    fn get_block(&self, position: usize) -> Self::Block {
        self.get_bits(Self::Block::mul_nbits(position), Self::Block::nbits())
    }
}

impl<'a, Base: 'a + BitVecMut + ?Sized> BitVecMut for BitSliceMut<'a, Base> {
    #[inline]
    fn set_bit(&mut self, position: u64, value: bool) {
        assert!(position < self.len, "BitSlice::set_bit: out of bounds");
        self.data.set_bit(self.start + position, value);
    }

    fn set_bits(&mut self, position: u64, count: usize, value: Self::Block) {
        let end = position.checked_add(count as u64)
                          .expect("BitSliceMut::get_bits: index overflow");
        assert!(end <= self.len, "BitSliceMut::get_bits: out of bounds");
        self.data.set_bits(self.start + position, count, value);
    }

    fn set_block(&mut self, position: usize, value: Self::Block) {
        self.set_bits(Self::Block::mul_nbits(position),
                      Self::Block::nbits(), value);
    }
}

impl<'a, Base: 'a + BitVec + ?Sized> SpaceUsage for BitSlice<'a, Base> {
    fn is_stack_only() -> bool { true }
    fn heap_bytes(&self) -> usize { 0 }
}

impl<'a, Base: 'a + BitVecMut + ?Sized> SpaceUsage for BitSliceMut<'a, Base> {
    fn is_stack_only() -> bool { true }
    fn heap_bytes(&self) -> usize { 0 }
}

/// Range polymorphism support.
///
/// The idea is to realize partial ranges by providing start limits to fill
/// in the missing bounds.
///
/// # Examples
///
/// ```
/// use succinct::bit_vec::IntoRange;
///
/// assert_eq!((3..5).into_range(0, 8), 3..5);
/// assert_eq!(( ..5).into_range(0, 8), 0..5);
/// assert_eq!((3.. ).into_range(0, 8), 3..8);
/// assert_eq!(( .. ).into_range(0, 8), 0..8);
/// ```
pub trait IntoRange<T> {
    /// Instantiates a range to a structure by provided bounds where bounds
    /// are absent.
    fn into_range(self, start: T, limit: T) -> Range<T>;
}

impl<T> IntoRange<T> for Range<T> {
    fn into_range(self, _: T, _: T) -> Range<T> { self }
}

impl<T> IntoRange<T> for RangeTo<T> {
    fn into_range(self, start: T, _: T) -> Range<T> { start .. self.end }
}

impl<T> IntoRange<T> for RangeFrom<T> {
    fn into_range(self, _: T, end: T) -> Range<T> { self.start .. end }
}

impl<T> IntoRange<T> for RangeFull {
    fn into_range(self, start: T, end: T) -> Range<T> { start .. end }
}