regex-tokenizer

A regex tokenizer

2 releases

0.1.1 Mar 22, 2023
0.1.0 Mar 22, 2023

#230 in Parser tooling

26 downloads per month

MIT license

9KB
146 lines

regex-tokenizer

Alla pugna! Crates.io (latest)

A regex-based tokenizer with a minimal DSL to define it!

Usage

tokenizer! {
    SimpleTokenizer

    r"[a-zA-Z]\w*" => Identifier
    r"\d+" => Number
    r"\s+" => _
}

And, in a function

...
let tokenizer = SimpleTokenizer::new();
...

SimpleTokenizer will generate an enum called SimpleTokenyzer_types, containing Identifier and Number. Regexes with _ as class are ignored; when a substring that does not match a specified regex is found, the tokenization is considered failed.

When multiple non-ignored regexes match with an input, priority is given to the one defined first.

Calling tokenizer.tokenize(...) will return an iterator that extracts tokens from the query. A token is formed by:

{
    value: String,
    position: usize,
    type_: SimpleTokenyzer_types,
}

position will be the position of the token's first character inside the query. A call to .next() will return None if there are no more tokens to extract.

Dependencies

~2.2–3.5MB
~56K SLoC