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mod louds_impl;

extern crate fid_rs;
use fid_rs::Fid;

#[cfg(feature = "serde")]
use serde::{Deserialize, Serialize};

#[cfg(feature = "mem_dbg")]
use mem_dbg::{MemDbg, MemSize};

/// LOUDS (Level-Order Unary Degree Sequence).
///
/// This class can handle tree structure of virtually **arbitrary number of nodes**.
///
/// In fact, _N_ (number of nodes in the tree) is designed to be limited to: _N < 2^64 / 2_, while each node is represented in 2bits in average.<br>
/// It should be enough for almost all usecases since a binary data of length of _2^63_ consumes _2^20 = 1,048,576_ TB (terabytes), which is hard to handle by state-of-the-art computer architecture.
#[derive(Clone, Debug)]
#[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
#[cfg_attr(feature = "mem_dbg", derive(MemDbg, MemSize))]
pub struct Louds {
    lbs: Fid,
}

#[derive(PartialEq, Eq, Debug, Clone, Copy)]
#[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
#[cfg_attr(feature = "mem_dbg", derive(MemDbg, MemSize))]
#[repr(transparent)]
/// Node number of [Louds](struct.Louds.html) tree
pub struct LoudsNodeNum(pub u64);

#[derive(PartialEq, Eq, Debug, Clone, Copy)]
#[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
#[cfg_attr(feature = "mem_dbg", derive(MemDbg, MemSize))]
#[repr(transparent)]
/// Index of [Louds](struct.Louds.html) tree
pub struct LoudsIndex(pub u64);

/// An index iterator
pub struct ChildIndexIter<'a> {
    inner: &'a Louds,
    node: LoudsNodeNum,
    start: Option<u64>,
    end: Option<u64>,
}
/// A node iterator
pub struct ChildNodeIter<'a>(ChildIndexIter<'a>);

/// An ancestor node iterator
pub struct AncestorNodeIter<'a> {
    inner: &'a Louds,
    node: LoudsNodeNum,
}