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use std::borrow::{Borrow, BorrowMut};
use std::ops::{Deref, DerefMut};
use serde::{Deserialize, Serialize};
#[derive(Debug, Clone, Serialize, Deserialize, Eq, PartialEq)]
pub struct Token {
pub offset_from: usize,
pub offset_to: usize,
pub position: usize,
pub text: String,
pub position_length: usize,
}
impl Default for Token {
fn default() -> Token {
Token {
offset_from: 0,
offset_to: 0,
position: usize::MAX,
text: String::with_capacity(200),
position_length: 1,
}
}
}
pub trait Tokenizer: 'static + Send + Sync + TokenizerClone {
fn token_stream<'a>(&self, text: &'a str) -> BoxTokenStream<'a>;
}
pub trait TokenizerClone {
fn box_clone(&self) -> Box<dyn Tokenizer>;
}
impl<T: Tokenizer + Clone> TokenizerClone for T {
fn box_clone(&self) -> Box<dyn Tokenizer> {
Box::new(self.clone())
}
}
pub struct BoxTokenStream<'a>(Box<dyn TokenStream + 'a>);
impl<'a, T> From<T> for BoxTokenStream<'a>
where T: TokenStream + 'a
{
fn from(token_stream: T) -> BoxTokenStream<'a> {
BoxTokenStream(Box::new(token_stream))
}
}
impl<'a> Deref for BoxTokenStream<'a> {
type Target = dyn TokenStream + 'a;
fn deref(&self) -> &Self::Target {
&*self.0
}
}
impl<'a> DerefMut for BoxTokenStream<'a> {
fn deref_mut(&mut self) -> &mut Self::Target {
&mut *self.0
}
}
impl<'a> TokenStream for Box<dyn TokenStream + 'a> {
fn advance(&mut self) -> bool {
let token_stream: &mut dyn TokenStream = self.borrow_mut();
token_stream.advance()
}
fn token<'b>(&'b self) -> &'b Token {
let token_stream: &'b (dyn TokenStream + 'a) = self.borrow();
token_stream.token()
}
fn token_mut<'b>(&'b mut self) -> &'b mut Token {
let token_stream: &'b mut (dyn TokenStream + 'a) = self.borrow_mut();
token_stream.token_mut()
}
}
pub trait TokenStream {
fn advance(&mut self) -> bool;
fn token(&self) -> &Token;
fn token_mut(&mut self) -> &mut Token;
fn next(&mut self) -> Option<&Token> {
if self.advance() {
Some(self.token())
} else {
None
}
}
fn process(&mut self, sink: &mut dyn FnMut(&Token)) {
while self.advance() {
sink(self.token());
}
}
}
pub struct BoxTokenFilter(Box<dyn TokenFilter>);
impl Deref for BoxTokenFilter {
type Target = dyn TokenFilter;
fn deref(&self) -> &dyn TokenFilter {
&*self.0
}
}
impl<T: TokenFilter> From<T> for BoxTokenFilter {
fn from(tokenizer: T) -> BoxTokenFilter {
BoxTokenFilter(Box::new(tokenizer))
}
}
pub trait TokenFilterClone {
fn box_clone(&self) -> BoxTokenFilter;
}
pub trait TokenFilter: 'static + Send + Sync + TokenFilterClone {
fn transform<'a>(&self, token_stream: BoxTokenStream<'a>) -> BoxTokenStream<'a>;
}
impl<T: TokenFilter + Clone> TokenFilterClone for T {
fn box_clone(&self) -> BoxTokenFilter {
BoxTokenFilter::from(self.clone())
}
}
#[cfg(test)]
mod test {
use super::*;
#[test]
fn clone() {
let t1 = Token {
position: 1,
offset_from: 2,
offset_to: 3,
text: "abc".to_string(),
position_length: 1,
};
let t2 = t1.clone();
assert_eq!(t1.position, t2.position);
assert_eq!(t1.offset_from, t2.offset_from);
assert_eq!(t1.offset_to, t2.offset_to);
assert_eq!(t1.text, t2.text);
}
}