diff --git a/src/main.rs b/src/regexp/token.rs
copy from src/main.rs
copy to src/regexp/token.rs
--- a/src/main.rs
+++ b/src/regexp/token.rs
@@ -1,28 +1,24 @@
-use std::collections::{HashMap, HashSet};
-
-const START: usize = usize::MAX;
-
-trait Token {
+pub trait Token {
 	fn is_skippable(&self) -> bool {false}
 	fn list_first(&self) -> Vec<usize>;
 	fn list_last(&self) -> Vec<usize>;
 	fn list_neighbours(&self) -> Vec<(usize, usize)>;
 }
 
-struct Symbol {
+pub struct Symbol {
 	position: usize,
 	value: char
 }
 
-struct Asterisk {
+pub struct Asterisk {
 	content: Box<dyn Token>
 }
 
-struct Plus {
+pub struct Plus {
 	content: Box<dyn Token>
 }
 
-struct Chain {
+pub struct Chain {
 	content: Vec<Box<dyn Token>>
 }
 
@@ -148,7 +144,7 @@ fn find_closing_parenthesis(s: &String) 
 	return None;
 }
 
-fn parse(pattern: &String, offset: usize) -> Chain {
+pub fn parse(pattern: &String, offset: usize) -> Chain {
 	let chars: Vec<char> = pattern.chars().collect();
 	let mut res: Vec<Box<dyn Token>> = Vec::new();
 	let mut i = 0;
@@ -181,153 +177,12 @@ fn parse(pattern: &String, offset: usize
 	return Chain{content: res};
 }
 
-fn encode_set(set: &HashSet<usize>) -> u64 {
-	let mut res = 0;
-	for x in set.iter() {
-		res ^= 1<<x;
-	}
-	return res;
-}
-
-fn decode_set(x: u64) ->HashSet<usize> {
-	if x == START as u64 {return HashSet::from([START]);}
-
-	let mut x = x;
-	let mut res: HashSet<usize> = HashSet::new();
-	
-	while x > 0 {
-		let y = x.trailing_zeros();
-		res.insert(y as usize);
-		x ^= 1 << y;
-	}
-
-	return res;
-}
-
-struct Regexp {
-	rules: HashMap<(usize, char), HashSet<usize>>,
-	end_states: HashSet<usize>
-}
-
-impl Regexp {
-	fn new(pattern: &String) -> Regexp {
-		let r = parse(pattern, 0);
-		let pattern_chars = Vec::from_iter(pattern.chars());
-		let mut rules: HashMap<(usize, char), HashSet<usize>> = HashMap::new();
-		
-		for i in r.list_first() {
-			let c = pattern_chars[i];
-			let key = (START, c);
-			match rules.get_mut(&key) {
-				Some(set) => {set.insert(i);},
-				None => {rules.insert(key, HashSet::from([i]));}
-			};
-		}
-
-		for (i, j) in r.list_neighbours() {
-			let c = pattern_chars[j];
-			let key = (i, c);
-			match rules.get_mut(&key) {
-				Some(set) => {set.insert(j);},
-				None => {rules.insert(key, HashSet::from([j]));}
-			};
-		}
-
-		let mut end_states = HashSet::from_iter(r.list_last().into_iter());
-		if r.is_skippable() {
-			end_states.insert(START);
-		}
+mod test {
+	use super::*;
 
-		return Regexp{rules, end_states};
-	}
-
-	pub fn eval(&self, s: String) -> bool {
-		let mut multistate = HashSet::from([START]);
-
-		for c in s.chars() {
-			let mut new_multistate = HashSet::new();
-
-			for state in multistate {
-				if let Some(x) = self.rules.get(&(state, c)) {
-					new_multistate = new_multistate.union(&x).map(|&y| y).collect();
-				} else if let Some(x) = self.rules.get(&(state, '.')) {
-					new_multistate = new_multistate.union(&x).map(|&y| y).collect();
-				}
-			}
-			multistate = new_multistate;
-		}
-
-		return multistate.iter().any(|x| self.end_states.contains(x));
-	}
-
-	fn determinize(&self) -> RegexpDFA {
-		let mut rules: HashMap<(u64, char), u64> = HashMap::new();
-		let mut end_states: HashSet<u64> = HashSet::new();
-		if self.end_states.contains(&START) {end_states.insert(START as u64);}
-
-		let mut stack = Vec::from([START as u64]);
-		let mut processed_states = HashSet::new();
-		while !stack.is_empty() {
-			let state = stack.pop().unwrap();
-			let multistate = decode_set(state);
-			let mut new_rules: HashMap<char, HashSet<usize>> = HashMap::new();
-
-			for key in self.rules.keys().filter(|key| multistate.contains(&key.0)) {
-				let (_st, c) = key;
-				if !new_rules.contains_key(c) {
-					new_rules.insert(*c, HashSet::new());
-				}
-				for target in &self.rules[key] {
-					new_rules.get_mut(c).unwrap().insert(*target);
-				}
-			}
-
-			for (c, target_set) in new_rules.into_iter() {
-				let encoded_target = encode_set(&target_set);
-				rules.insert((state, c), encoded_target);
-				if target_set.iter().any(|st| self.end_states.contains(st)) {
-					end_states.insert(encoded_target);
-				}
-				if !processed_states.contains(&encoded_target) {
-					stack.push(encoded_target);
-					processed_states.insert(encoded_target);
-				}
-			}
-		}
-
-		return RegexpDFA{rules, end_states};
+	#[test]
+	fn test_closing_parenthesis() {
+		let s = "()";
+		assert_eq!(find_closing_parenthesis(&s.to_string()), Some(1));
 	}
 }
-
-struct RegexpDFA {
-	rules: HashMap<(u64, char), u64>,
-	end_states: HashSet<u64>
-}
-
-impl RegexpDFA {
-	fn eval(&self, s: String) -> bool {
-		let mut state = START as u64;
-
-		for c in s.chars() {
-			if let Some(x) = self.rules.get(&(state, c)) {
-				state = *x;
-			} else {
-				return false;
-			}
-		}
-
-		return self.end_states.contains(&state);
-	}
-}
-
-fn main() {
-	let tests = ["", "a", "ab", "aabb", "abab", "abcd", "abcbcdbcd"];
-	for pattern in ["a*b*", "a+b+", "(ab)*", "(ab)+", "a((bc)*d)*"] {
-		println!("# {pattern}");
-		let r = Regexp::new(&pattern.to_string()).determinize();
-		for &t in tests.iter() {
-			println!("{t} {}", r.eval(t.to_string()));
-		}
-		println!();
-	}
-}