Crate muncher

muncher is a library for lexing a string of text input. The main struct Muncher can be crated from any &str and forks or peeking and seeking without moving the cursor forward can be accomplished via fork, peek and seek.

Creation and Peeking

use muncher::Muncher;
 
let input = "hello world";
let m = Muncher::new(input);
 
assert_eq!(m.seek(5), Some("hello".to_string()));
assert_eq!(m.peek(), Some(&' '));
assert_eq!(m.seek(5), Some("world".to_string()));
assert!(m.peek().is_none());

let input = "abcde";
let mut munch = Muncher::new(input);
assert_eq!(munch.eat(), Some('a'));
 
let fork = munch.fork();
assert_eq!(fork.peek(), Some(&'b'));
assert_eq!(munch.eat(), Some('b'));

Muncher has many eat_* methods as well as eat that are used to advance the cursor. eat returns an Option<char> if you want to use the returned char. Another way of advancing the cursor is the eat_until, eat_until_count and eat_range_of methods.

eat_until

use muncher::Muncher;

let input = "abcde";
let mut munch = Muncher::new(input);

let text = munch.eat_until(|ch| ch == &'d').collect::<String>();
assert_eq!(text, "abc");
assert_eq!(munch.eat(), Some('d'));

eat_until_count works the same but returns (usize, usize) as (start, end).

eat_range_of

use muncher::Muncher;

let input = "abcde";
let mut munch = Muncher::new(input);

let (start, end) = munch.eat_range_of("d");
assert_eq!(&munch.text()[start..end], "abc");
assert_eq!(munch.eat(), Some('d'));

Structs

Fork
Muncher
Stack

Enums

StackResult