Tokenizer-lib

Tokenization utilities for building parsers in Rust

Examples

Buffered token channel:

use tokenizer_lib::{BufferedTokenQueue, Token, TokenReader, TokenSender, TokenTrait};

#[derive(PartialEq, Debug)]
struct Span(pub u32, pub u32);

#[derive(PartialEq, Debug)]
struct N(pub u32);

impl TokenTrait for N {}

let mut btq = BufferedTokenQueue::new();
btq.push(Token(N(12), Span(0, 2)));
btq.push(Token(N(32), Span(2, 4)));
btq.push(Token(N(52), Span(4, 8)));
assert_eq!(btq.next().unwrap().0, N(12));
assert_eq!(btq.next().unwrap().0, N(32));
assert_eq!(btq.next().unwrap().0, N(52));
assert!(btq.next().is_none());

(Multi-thread safe) Parallel token queue:

use tokenizer_lib::{ParallelTokenQueue, Token, TokenReader, TokenSender, TokenTrait};

#[derive(PartialEq, Debug)]
struct Span(pub u32, pub u32);

#[derive(PartialEq, Debug)]
struct N(pub u32);

impl TokenTrait for N {}

let (mut sender, mut reader) = ParallelTokenQueue::new();
std::thread::spawn(move || {
    sender.push(Token(N(12), Span(0, 2)));
    sender.push(Token(N(32), Span(2, 4)));
    sender.push(Token(N(52), Span(4, 8)));
});

assert_eq!(reader.next().unwrap().0, N(12));
assert_eq!(reader.next().unwrap().0, N(32));
assert_eq!(reader.next().unwrap().0, N(52));
assert!(reader.next().is_none());

Generator token queue:

use tokenizer_lib::{GeneratorTokenQueue, GeneratorTokenQueueBuffer, Token, TokenReader, TokenSender, TokenTrait};

#[derive(PartialEq, Debug)]
struct N(pub u32);

impl TokenTrait for N {}

fn lexer(state: &mut u32, sender: &mut GeneratorTokenQueueBuffer<N, ()>) {
    *state += 1;
    match state {
        1..=3 => {
            sender.push(Token(N(*state * 2), ()));
        }
        _ => {}
    }
}

let mut reader = GeneratorTokenQueue::new(lexer, 0);

assert_eq!(reader.next().unwrap().0, N(2));
assert_eq!(reader.next().unwrap().0, N(4));
assert_eq!(reader.next().unwrap().0, N(6));
assert!(reader.next().is_none());

Provides utilities such as peek, peek_n and scan for lookahead. Also expect_next for expecting a token value and conditional_next for advancing on a predicate.