Lexer crate derived from Regex patterns with user customizeable tokens
Potential code one might use for lexing tokens for a calculator
key.json:
{
"literals": {
"number": "[0-9]*[0-9]",
"subtract": "-",
"add": "\\+",
"divide": "/",
"multiply": "\\*"
},
"whitespace": "\n| |\r|\t"
}
main.rs:
```
let json: String = std::fs::readtostring("key.json").unwrap();
let source: String = String::from("123 + 456 * 789");
let mut lexer = Lexer::from(json, source); while !lexer.done() { println!("{}", lexer.next_token().unwrap()); } ```
number(123)
add(+)
number(456)
multiply(*)
number(789)