Lexer Validation

There are additional restrictions that are enforced at compile-time apart from the ones covered previously

Duplicated Terminals

Having duplicated terminals is likely a mistake, because those terminals are interchangeable in the syntax tree. Likewise, you cannot have 2 terminals with no literals.

use teleparse::prelude::*;
#[derive_lexicon]
pub enum MyToken {
    #[teleparse(terminal(Zero = "0", Another = "0"))]
    Integer,
}
fn main() {}

error: Duplicate literal pattern `0` for variant `Integer`.
 --> tests/ui/lex_no_dupe_literal.rs:4:48
  |
4 |     #[teleparse(terminal(Zero = "0", Another = "0"))]
  |                                                ^^^

Regex Features

Teleparse uses the logos crate for the lexer, which combines all the rules into a single state machine for performance. Logos also imposes additional restrictions on regex features that requires backtracking. Please refer to their documentation for more information.