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use std::cmp::{Eq, Ord, Ordering, PartialEq};
use std::collections::HashMap;
use std::default::Default;
use std::fmt;
use std::hash::{Hash, Hasher};
use std::iter::Iterator;
use std::mem;
pub struct Symbol<T, D> where D: SymbolId {
id: D,
data: T,
next: Option<Box<Symbol<T, D>>>,
}
impl<T, D> Symbol<T, D> where D: SymbolId {
pub fn id(&self) -> &D {
&self.id
}
pub fn data(&self) -> &T {
&self.data
}
}
impl<T, D> Hash for Symbol<T, D> where T: Hash, D: SymbolId {
fn hash<H>(&self, state: &mut H) where H: Hasher {
self.data.hash(state)
}
}
impl<T, D> PartialEq for Symbol<T, D> where T: PartialEq, D: SymbolId {
fn eq(&self, other: &Self) -> bool {
self.data.eq(&other.data)
}
}
impl<T, D> Eq for Symbol<T, D> where T: Eq, D: SymbolId { }
impl<T, D> PartialOrd for Symbol<T, D> where T: PartialOrd, D: SymbolId {
fn partial_cmp(&self, other: &Self) -> Option<Ordering> {
self.data.partial_cmp(&other.data)
}
}
impl<T, D> Ord for Symbol<T, D> where T: Ord, D: SymbolId {
fn cmp(&self, other: &Self) -> Ordering {
self.data.cmp(&other.data)
}
}
pub trait SymbolId:
Copy + Clone + fmt::Debug + Default + Eq + Hash + Ord + PartialEq + PartialOrd + Send + Sync {
fn next(&self) -> Self;
fn as_usize(&self) -> usize;
}
impl SymbolId for usize {
fn next(&self) -> Self { *self + 1 }
fn as_usize(&self) -> usize { *self }
}
impl SymbolId for u8 {
fn next(&self) -> Self { *self + 1 }
fn as_usize(&self) -> usize { *self as usize }
}
impl SymbolId for u16 {
fn next(&self) -> Self { *self + 1 }
fn as_usize(&self) -> usize { *self as usize }
}
impl SymbolId for u32 {
fn next(&self) -> Self { *self + 1 }
fn as_usize(&self) -> usize { *self as usize }
}
impl SymbolId for u64 {
fn next(&self) -> Self { *self + 1 }
fn as_usize(&self) -> usize { *self as usize }
}
pub struct Table<T, D> where D: SymbolId {
head: Option<Box<Symbol<T, D>>>,
next_id: D,
}
impl<T, D> Table<T, D> where D: SymbolId {
pub fn new() -> Self {
Table {
head: None,
next_id: Default::default(),
}
}
pub fn len(&self) -> usize {
self.next_id.as_usize()
}
pub fn insert(&mut self, value: T) -> &Symbol<T, D> {
let next_id = self.next_id;
self.next_id = self.next_id.next();
let mut new_head = Box::new(Symbol {
id: next_id,
data: value,
next: None,
});
mem::swap(&mut self.head, &mut new_head.next);
self.head = Some(new_head);
(&self.head).as_ref().unwrap()
}
pub fn remap<F>(&mut self, mut f: F) where F: FnMut(&Symbol<T, D>) -> Option<D> {
let mut remapped = Table::new();
let mut head = None;
mem::swap(&mut head, &mut self.head);
loop {
head = match head {
None => break,
Some(mut symbol) =>
if let Some(new_state_id) = f(&symbol) {
let mut next_head = None;
mem::swap(&mut next_head, &mut symbol.next);
symbol.id = new_state_id;
remapped.emplace_head(symbol);
remapped.next_id = remapped.next_id.next();
next_head
} else {
symbol.next
},
}
}
mem::swap(&mut remapped, self);
}
pub fn into_iter(self) -> TableIntoIter<T, D> {
TableIntoIter {
remaining: self.len(),
item: self.head,
}
}
pub fn iter<'s>(&'s self) -> TableIter<'s, T, D> {
TableIter {
remaining: self.len(),
item: (&self.head).as_ref(),
}
}
fn emplace_head(&mut self, mut value: Box<Symbol<T, D>>) {
mem::swap(&mut value.next, &mut self.head);
mem::swap(&mut self.head, &mut Some(value));
}
}
impl<T, D> Table<T, D> where T: Eq + Hash, D: SymbolId {
pub fn to_hash_map(mut self) -> HashMap<T, D> {
let mut map = HashMap::with_capacity(self.len());
loop {
self.head = match self.head {
None => break,
Some(mut symbol) => {
let id = symbol.id().clone();
let mut next_head = None;
mem::swap(&mut next_head, &mut symbol.next);
map.insert(symbol.data, id);
next_head
},
}
}
map
}
}
impl<'a, T, D> IntoIterator for &'a Table<T, D> where T: 'a, D: 'a + SymbolId {
type Item = &'a Symbol<T, D>;
type IntoIter = TableIter<'a, T, D>;
fn into_iter(self) -> Self::IntoIter {
self.iter()
}
}
impl<T, D> IntoIterator for Table<T, D> where D: SymbolId {
type Item = Box<Symbol<T, D>>;
type IntoIter = TableIntoIter<T, D>;
fn into_iter(self) -> Self::IntoIter {
self.into_iter()
}
}
pub struct TableIter<'a, T, D> where T: 'a, D: 'a + SymbolId {
remaining: usize,
item: Option<&'a Box<Symbol<T, D>>>,
}
impl<'a, T, D> Iterator for TableIter<'a, T, D> where T: 'a, D: 'a + SymbolId {
type Item = &'a Symbol<T, D>;
fn next(&mut self) -> Option<&'a Symbol<T, D>> {
let mut item = None;
mem::swap(&mut item, &mut self.item);
match item {
None => None,
Some(symbol) => {
self.remaining -= 1;
self.item = symbol.next.as_ref();
Some(symbol)
},
}
}
fn size_hint(&self) -> (usize, Option<usize>) {
(self.remaining, Some(self.remaining))
}
}
pub struct TableIntoIter<T, D> where D: SymbolId {
remaining: usize,
item: Option<Box<Symbol<T, D>>>,
}
impl<T, D> Iterator for TableIntoIter<T, D> where D: SymbolId {
type Item = Box<Symbol<T, D>>;
fn next(&mut self) -> Option<Box<Symbol<T, D>>> {
let mut item = None;
mem::swap(&mut item, &mut self.item);
match item {
None => None,
Some(mut symbol) => {
self.remaining -= 1;
mem::swap(&mut self.item, &mut symbol.next);
Some(symbol)
},
}
}
fn size_hint(&self) -> (usize, Option<usize>) {
(self.remaining, Some(self.remaining))
}
}
#[cfg(test)]
mod test {
use super::{Symbol, SymbolId, Table};
use std::collections::HashMap;
use std::default::Default;
const VALUES: &'static [usize] = &[101, 203, 500, 30, 0, 1];
#[test]
fn symbol_id_ok() {
let id: usize = Default::default();
assert_eq!(id.as_usize(), 0);
assert_eq!(id.next().as_usize(), 1);
assert_eq!(id.next().next().as_usize(), 2);
assert_eq!(id.as_usize(), 0);
}
#[test]
fn new_table_empty_ok() {
let t = Table::<usize, usize>::new();
assert!(t.head.is_none());
assert!(t.next_id == 0);
assert_eq!(t.len(), 0);
}
#[test]
fn table_insert_ok() {
let mut t = Table::<usize, usize>::new();
for (i, v) in VALUES.iter().enumerate() {
t.insert(*v);
assert_eq!(t.len(), i + 1);
assert_eq!(t.next_id.as_usize(), i + 1);
assert_eq!(t.head.as_ref().map(|x| x.data), Some(*v));
}
assert_eq!(t.len(), VALUES.len());
assert_eq!(t.next_id.as_usize(), VALUES.len());
let mut x = t.head.as_ref();
let mut count = 0;
let mut vs = VALUES.iter().rev().enumerate();
loop {
x = match x {
None => break,
Some(symbol) => {
let (i, v) = vs.next().unwrap();
assert_eq!(i, count);
assert_eq!(symbol.data(), v);
count += 1;
symbol.next.as_ref()
},
}
}
assert_eq!(vs.next(), None);
}
#[test]
fn table_empty_iter_ok() {
let t = Table::<usize, usize>::new();
let mut i = t.iter();
assert_eq!(i.size_hint(), (0, Some(0)));
assert!(i.next().is_none());
assert_eq!(i.size_hint(), (0, Some(0)));
}
#[test]
fn table_iter_ok() {
let mut t = Table::<usize, u32>::new();
for v in VALUES.iter() {
t.insert(*v);
}
assert_eq!(t.len(), VALUES.len());
let mut i = t.iter();
let mut expected_len = t.len();
let mut vs = VALUES.iter().rev();
assert_eq!(i.size_hint(), (expected_len, Some(expected_len)));
while let Some(symbol) = i.next() {
expected_len -= 1;
assert_eq!(i.size_hint(), (expected_len, Some(expected_len)));
assert_eq!(Some(symbol.data()), vs.next());
}
assert_eq!(i.size_hint(), (0, Some(0)));
}
#[test]
fn moved_table_internal_address_unchanged_ok() {
let mut stack_table = Table::<usize, u8>::new();
let mut original_data_addresses = Vec::new();
let mut original_symbol_addresses = Vec::new();
for v in VALUES.iter() {
let symbol = stack_table.insert(*v);
assert_eq!(*symbol.data(), *v);
original_data_addresses.push(symbol.data() as *const usize);
original_symbol_addresses.push(symbol as *const Symbol<usize, u8>);
}
let heap_table = Box::new(stack_table);
let mut count =0;
for (symbol, (value, (data_address, symbol_address))) in heap_table.iter().zip(
VALUES.iter().rev().zip(
original_data_addresses.into_iter().rev().zip(
original_symbol_addresses.into_iter().rev()))) {
assert_eq!(symbol.data(), value);
assert_eq!(symbol.data() as *const usize, data_address);
assert_eq!(symbol as *const Symbol<usize, u8>, symbol_address);
count += 1;
}
assert_eq!(count, VALUES.len());
}
#[test]
fn remap_empty_ok() {
let mut t = Table::<usize, u8>::new();
assert_eq!(t.len(), 0);
t.remap(|symbol| Some(symbol.id().clone()));
assert_eq!(t.len(), 0);
}
#[test]
fn remap_noop_ok() {
let mut t1 = Table::<usize, u8>::new();
for v in VALUES.iter() {
t1.insert(*v);
}
let mut t2 = Table::<usize, u8>::new();
for v in VALUES.iter() {
t2.insert(*v);
}
t2.remap(|symbol| Some(symbol.id().clone()));
assert_eq!(t2.len(), t1.len());
assert_eq!(t2.to_hash_map(), t1.to_hash_map());
}
#[test]
fn remap_all_ok() {
let mut t = Table::<usize, u8>::new();
for v in VALUES.iter() {
t.insert(*v);
}
let mut new_id = 0u8;
let mut expected_associations = HashMap::new();
t.remap(|symbol| {
let id = new_id;
new_id += 1;
expected_associations.insert(*symbol.data(), id);
Some(id)
});
assert_eq!(t.to_hash_map(), expected_associations);
}
#[test]
fn remap_some_ok() {
let mut t = Table::<usize, u8>::new();
for v in VALUES.iter() {
t.insert(*v);
}
let mut new_id = 0u8;
let mut expected_associations = HashMap::new();
t.remap(|symbol|
if symbol.id() % 2 == 0 {
let id = new_id;
new_id += 1;
expected_associations.insert(*symbol.data(), id);
Some(id)
} else {
None
});
assert_eq!(t.to_hash_map(), expected_associations);
}
#[test]
fn remap_none_ok() {
let mut t = Table::<usize, u8>::new();
for v in VALUES.iter() {
t.insert(*v);
}
t.remap(|_| None);
assert_eq!(t.len(), 0);
}
#[test]
fn table_empty_into_iter_ok() {
let t = Table::<usize, u8>::new();
assert!(t.into_iter().next().is_none());
}
#[test]
fn table_into_iter_ok() {
let mut t = Table::<usize, u32>::new();
for v in VALUES.iter() {
t.insert(*v);
}
assert_eq!(t.len(), VALUES.len());
let mut expected_len = t.len();
let mut i = t.into_iter();
let mut vs = VALUES.iter().rev();
assert_eq!(i.size_hint(), (expected_len, Some(expected_len)));
while let Some(symbol) = i.next() {
expected_len -= 1;
assert_eq!(i.size_hint(), (expected_len, Some(expected_len)));
assert_eq!(Some(symbol.data()), vs.next());
}
assert_eq!(i.size_hint(), (0, Some(0)));
}
}