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use ibig::UBig;
use num_traits::{Zero, One};
use std::collections::HashSet;
use crate::types::*;
use crate::iterators::*;
///Trait for objects that can be anahashed (string-like)
pub trait Anahashable {
fn anahash(&self, alphabet: &Alphabet) -> AnaValue;
fn normalize_to_alphabet(&self, alphabet: &Alphabet) -> NormString;
}
impl Anahashable for str {
///Compute the anahash for a given string, according to the alphabet
fn anahash(&self, alphabet: &Alphabet) -> AnaValue {
let mut hash: AnaValue = AnaValue::empty();
let mut skip = 0;
for (pos, _) in self.char_indices() {
if skip > 0 {
skip -= 1;
continue;
}
let mut matched = false;
'abciter: for (seqnr, chars) in alphabet.iter().enumerate() {
for element in chars.iter() {
let l = element.chars().count();
if let Some(slice) = self.get(pos..pos+l) {
if slice == element {
let charvalue = AnaValue::character(seqnr as CharIndexType);
hash = hash.insert(&charvalue);
matched = true;
skip = l-1;
break 'abciter;
}
}
}
}
if !matched {
//Highest one is reserved for UNK
let charvalue = AnaValue::character(alphabet.len() as CharIndexType);
hash = hash.insert(&charvalue);
}
}
hash
}
///Normalize a string via the alphabet
fn normalize_to_alphabet(&self, alphabet: &Alphabet) -> NormString {
let mut result = Vec::with_capacity(self.chars().count());
let mut skip = 0;
for (pos, _) in self.char_indices() {
if skip > 0 {
skip -= 1;
continue;
}
//does greedy matching in order of appearance in the alphabet file
let mut matched = false;
'abciter: for (i, chars) in alphabet.iter().enumerate() {
for element in chars.iter() {
let l = element.chars().count();
if let Some(slice) = self.get(pos..pos+l) {
if slice == element {
result.push(i as CharIndexType);
matched = true;
skip = l-1;
break 'abciter;
}
}
}
}
if !matched {
//Highest one is reserved for UNK
result.push(alphabet.len() as CharIndexType + 1);
}
}
result
}
}
/// This trait can be applied to types
/// that can function as anahashes.
/// It can be implemented for integer types.
pub trait Anahash: One + Zero {
fn character(seqnr: CharIndexType) -> AnaValue;
fn empty() -> AnaValue;
fn is_empty(&self) -> bool;
fn insert(&self, value: &AnaValue) -> AnaValue;
fn delete(&self, value: &AnaValue) -> Option<AnaValue>;
fn contains(&self, value: &AnaValue) -> bool;
fn iter(&self, alphabet_size: CharIndexType) -> RecurseDeletionIterator;
fn iter_parents(&self, alphabet_size: CharIndexType) -> DeletionIterator;
fn iter_recursive(&self, alphabet_size: CharIndexType, params: &SearchParams) -> RecurseDeletionIterator;
fn iter_recursive_external_cache<'a>(&self, alphabet_size: CharIndexType, params: &SearchParams, cache: &'a mut HashSet<AnaValue>) -> RecurseDeletionIterator<'a>;
/// Computes the number of characters in this anagram
fn char_count(&self, alphabet_size: CharIndexType) -> u16 {
self.iter(alphabet_size).count() as u16
}
/// Count how many times an anagram value occurs in this anagram
fn count_matches(&self, value: &AnaValue) -> usize {
if let Some(result) = self.delete(value) {
1 + result.count_matches(value)
} else {
0
}
}
/// Returns the the upper bound of the alphabet size
/// as used in this anavalue, which may be lower
/// than the actual alphabet size.
/// Returns a character index in the alphabet,
/// also returns the character count as 2nd member of the tuple
fn alphabet_upper_bound(&self, alphabet_size: CharIndexType) -> (CharIndexType, u16) {
let mut maxcharindex = 0;
let mut count = 0;
for (result, _) in self.iter(alphabet_size) {
count += 1;
if result.charindex > maxcharindex {
maxcharindex = result.charindex;
}
}
(maxcharindex, count)
}
}
impl Anahash for AnaValue {
/// Computes the Anagram value for the n'th entry in the alphabet
fn character(seqnr: CharIndexType) -> AnaValue {
UBig::from(PRIMES[seqnr as usize])
}
/// Insert the characters represented by the anagram value, returning the result
fn insert(&self, value: &AnaValue) -> AnaValue {
if self == &AnaValue::zero() {
value.clone()
} else {
self * value
}
}
/// Delete the characters represented by the anagram value, returning the result
/// Returns None of the anagram was not found
fn delete(&self, value: &AnaValue) -> Option<AnaValue> {
if self.contains(value) {
Some(self / value)
} else {
None
}
}
/// Tests if the anagram value contains the specified anagram value
fn contains(&self, value: &AnaValue) -> bool {
if value > self {
false
} else {
(self % value) == AnaValue::zero()
}
}
/// Iterate over all characters in this alphabet
/// Returns DeletionResult instances that holds
/// a `charindex` attribute indicating the index
/// in the alphabet. If there are duplicates,
/// this iterator returns them all.
///
/// # Examples
///
/// ```
/// # use analiticcl::*;
/// # use analiticcl::test::*;
/// # use std::ops::Deref;
/// # let (alphabet, alphabet_size) = get_test_alphabet();
/// let anavalue: AnaValue = "house".anahash(&alphabet);
/// let mut chars: Vec<AnaValue> = Vec::new();
/// for (deletion, depth) in anavalue.iter(alphabet_size) {
/// chars.push(AnaValue::character(deletion.charindex));
/// }
/// ```
fn iter(&self, alphabet_size: CharIndexType) -> RecurseDeletionIterator {
RecurseDeletionIterator::new(self.clone(), alphabet_size, true, None, None, false,false,true, None)
}
/// Iterator over all the parents that are generated when applying all deletions within edit distance 1
fn iter_parents(&self, alphabet_size: CharIndexType) -> DeletionIterator {
DeletionIterator::new(self, alphabet_size)
}
/// Iterator over all the possible deletions within the specified anagram distance
fn iter_recursive(&self, alphabet_size: CharIndexType, params: &SearchParams) -> RecurseDeletionIterator {
RecurseDeletionIterator::new(self.clone(), alphabet_size, false, params.min_distance, params.max_distance, params.breadthfirst, !params.allow_duplicates, params.allow_empty_leaves, None )
}
/// Iterator over all the possible deletions within the specified anagram distance
fn iter_recursive_external_cache<'a>(&self, alphabet_size: CharIndexType, params: &SearchParams, cache: &'a mut HashSet<AnaValue>) -> RecurseDeletionIterator<'a> {
RecurseDeletionIterator::new(self.clone(), alphabet_size, false, params.min_distance, params.max_distance, params.breadthfirst, !params.allow_duplicates, params.allow_empty_leaves, Some(cache) )
}
/// The value of an empty anahash
/// Also corresponds to the root of the index
fn empty() -> AnaValue {
AnaValue::one()
}
/// The value of an empty anahash
/// Also corresponds to the root of the index
fn is_empty(&self) -> bool {
self == &AnaValue::empty() || self == &AnaValue::zero()
}
}
/// Search parameters used to pass to the Anahash::iter_recursive() function
pub struct SearchParams {
pub min_distance: Option<u32>,
pub max_distance: Option<u32>,
pub breadthfirst: bool,
pub allow_duplicates: bool,
pub allow_empty_leaves: bool,
}
impl Default for SearchParams {
fn default() -> Self {
SearchParams {
min_distance: None,
max_distance: None,
breadthfirst: false,
allow_duplicates: true,
allow_empty_leaves: true,
}
}
}