Changeset - 2810f86816cd
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Laman - 10 months ago 2024-06-29 00:16:42

added an explicit fail state, removed its special handling from the code
2 files changed with 25 insertions and 11 deletions:
regexp.py
9
4
src/regexp.rs
16
7
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regexp.py
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@@ -275,6 +275,10 @@ class Regexp:
 
				compact_rules[index[multistate]*n + alphabet_index[c]] = index[target_tup]
 
				if any(st in self.end_states for st in target_set):
 
					end_states.add(index[target_tup])
 

			




	
	
	
		
 
		fail = len(index)

			




	
	
	
		
 
		compact_rules = [(st if st >= 0 else fail) for st in compact_rules]

			




	
	
	
		
 
		compact_rules.extend([fail] * n)

			




	
	
	
		
 
		

			




	
	
	
		
 
		return (compact_rules, end_states, alphabet_index)

			




	
	
	
		
 

			




	
	
		
 
@@ -295,9 +299,10 @@ class RegexpDFA:

			




	
	
	
		
 
	def match(self, s):

			




	
	
	
		
 
		st = 0

			




	
	
	
		
 
		n = len(self.alphabet_index)

			




	
	
	
		
 
		fail = len(self.rules) // n

			




	
	
	
		
 

			




	
	
	
		
 
		for c in s:

			




	
	
	
		
 
			if c not in self.alphabet_index or st < 0:

			




	
	
	
		
 
			if c not in self.alphabet_index or st == fail:

			




	
	
	
		
 
				return False

			




	
	
	
		
 
			key = (st*n + self.alphabet_index[c])

			




	
	
	
		
 
			st = self.rules[key]

			




	
	
		
 
@@ -312,7 +317,7 @@ class RegexpDFA:

			




	
	
	
		
 

			




	
	
	
		
 
	def normalize(self):

			




	
	
	
		
 
		n = len(self.alphabet_index)

			




	
	
	
		
 
		index = {-1: -1, 0: 0}

			




	
	
	
		
 
		index = {0: 0}

			




	
	
	
		
 
		queue = deque([0])

			




	
	
	
		
 

			




	
	
	
		
 
		rules = []

			




	
	
		
 
@@ -322,7 +327,7 @@ class RegexpDFA:

			




	
	
	
		
 
			row = self.rules[si*n:(si+1)*n]

			




	
	
	
		
 
			for sj in row:

			




	
	
	
		
 
				if sj not in index:

			




	
	
	
		
 
					index[sj] = len(index)-1

			




	
	
	
		
 
					index[sj] = len(index)

			




	
	
	
		
 
					queue.append(sj)

			




	
	
	
		
 
			rules.extend(index[sj] for sj in row)

			




	
	
	
		
 
		

			




	
	
		
 
@@ -358,7 +363,7 @@ class RegexpDFA:

			




	
	
	
		
 
		for (s1, s2) in equivalents:

			




	
	
	
		
 
			eq_mapping[s2] = min(s1, eq_mapping.get(s2, math.inf))

			




	
	
	
		
 

			




	
	
	
		
 
		discard_mapping = {-1: -1}

			




	
	
	
		
 
		discard_mapping = dict()

			




	
	
	
		
 
		discard_count = 0

			




	
	
	
		
 

			




	
	
	
		
 
		for i in range(0, len(self.rules), n):

			




        

    


    
    

    

        

                

                    src/regexp.rs
                

                

                  
                      
                        

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@@ -6,7 +6,6 @@ use token::parse;

			




	
	
	
		
 

			




	
	
	
		
 
const START_NFA: usize = usize::MAX;

			




	
	
	
		
 
const START_DFA: usize = 0;

			




	
	
	
		
 
const FAIL: usize = usize::MAX>>1;

			




	
	
	
		
 

			




	
	
	
		
 
fn encode_set(set: &HashSet<usize>) -> String {

			




	
	
	
		
 
	let mut v = Vec::from_iter(set.iter());

			




	
	
		
 
@@ -80,6 +79,7 @@ impl Regexp {

			




	
	
	
		
 
	}

			




	
	
	
		
 

			




	
	
	
		
 
	pub fn determinize(&self) -> RegexpDFA {

			




	
	
	
		
 
		const FAIL: usize = usize::MAX;

			




	
	
	
		
 
		let alphabet_index: HashMap<char, usize> = self.alphabet.iter().enumerate().map(|(i, c)| (*c, i)).collect();

			




	
	
	
		
 
		let n = alphabet_index.len();

			




	
	
	
		
 
		let mut compact_rules = vec![FAIL; n];

			




	
	
		
 
@@ -124,6 +124,10 @@ impl Regexp {

			




	
	
	
		
 
			}

			




	
	
	
		
 
		}

			




	
	
	
		
 

			




	
	
	
		
 
		let fail = index_new.len();

			




	
	
	
		
 
		compact_rules = compact_rules.into_iter().map(|st| if st != FAIL {st} else {fail}).collect();

			




	
	
	
		
 
		compact_rules.extend(iter::repeat(fail).take(n));

			




	
	
	
		
 

			




	
	
	
		
 
		return RegexpDFA{rules: compact_rules, end_states, alphabet_index};

			




	
	
	
		
 
	}

			




	
	
	
		
 
}

			




	
	
		
 
@@ -137,6 +141,10 @@ pub struct RegexpDFA {

			




	
	
	
		
 
impl RegexpDFA {

			




	
	
	
		
 
	pub fn eval(&self, s: String) -> bool {

			




	
	
	
		
 
		let n = self.alphabet_index.len();

			




	
	
	
		
 
		if n == 0 {

			




	
	
	
		
 
			return s.len() == 0;

			




	
	
	
		
 
		}

			




	
	
	
		
 
		let fail = self.rules.len() / n;

			




	
	
	
		
 
		let mut state = START_DFA;

			




	
	
	
		
 

			




	
	
	
		
 
		for c in s.chars() {

			




	
	
		
 
@@ -145,7 +153,7 @@ impl RegexpDFA {

			




	
	
	
		
 
			} else {

			




	
	
	
		
 
				return false;

			




	
	
	
		
 
			}

			




	
	
	
		
 
			if state == FAIL {

			




	
	
	
		
 
			if state == fail {

			




	
	
	
		
 
				return false;

			




	
	
	
		
 
			}

			




	
	
	
		
 
		}

			




	
	
		
 
@@ -167,7 +175,8 @@ impl RegexpDFA {

			




	
	
	
		
 
			return RegexpDFA{rules: self.rules.clone(), end_states: self.end_states.clone(), alphabet_index: self.alphabet_index.clone()}; 

			




	
	
	
		
 
		}

			




	
	
	
		
 
		let m = self.rules.len()/n;

			




	
	
	
		
 
		let mut index: Vec<usize> = vec![FAIL;m];

			




	
	
	
		
 
		let fail = m;

			




	
	
	
		
 
		let mut index: Vec<usize> = vec![fail;m];

			




	
	
	
		
 
		index[0] = 0;

			




	
	
	
		
 
		let mut queue = VecDeque::from([START_DFA]);

			




	
	
	
		
 

			




	
	
		
 
@@ -178,13 +187,13 @@ impl RegexpDFA {

			




	
	
	
		
 
			let si = queue.pop_front().unwrap();

			




	
	
	
		
 
			let row = &self.rules[si*n..(si+1)*n];

			




	
	
	
		
 
			for &sj in row {

			




	
	
	
		
 
				if sj != FAIL && index[sj] == FAIL {

			




	
	
	
		
 
				if sj != fail && index[sj] == fail {

			




	
	
	
		
 
					index[sj] = k;

			




	
	
	
		
 
					k += 1;

			




	
	
	
		
 
					queue.push_back(sj);

			




	
	
	
		
 
				}

			




	
	
	
		
 
			}

			




	
	
	
		
 
			rules.extend(row.iter().map(|&st| if st != FAIL {index[st]} else {FAIL}));

			




	
	
	
		
 
			rules.extend(row.iter().map(|&st| index[st]));

			




	
	
	
		
 
		}

			




	
	
	
		
 

			




	
	
	
		
 
		let end_states = self.end_states.iter().map(|st| index[*st]).collect();

			




	
	
		
 
@@ -239,10 +248,10 @@ impl RegexpDFA {

			




	
	
	
		
 
				continue;

			




	
	
	
		
 
			}

			




	
	
	
		
 
			discard_mapping[si] = si-discard_count;

			




	
	
	
		
 
			rules.extend(self.rules[si*n..(si+1)*n].iter().map(|&st| if st!=FAIL {eq_mapping[st]} else {FAIL}));

			




	
	
	
		
 
			rules.extend(self.rules[si*n..(si+1)*n].iter().map(|&st| eq_mapping[st]));

			




	
	
	
		
 
		}

			




	
	
	
		
 

			




	
	
	
		
 
		rules = rules.into_iter().map(|st| if st!=FAIL {discard_mapping[st]} else {FAIL}).collect();

			




	
	
	
		
 
		rules = rules.into_iter().map(|st| discard_mapping[st]).collect();

			




	
	
	
		
 
		let end_states = self.end_states.iter().map(|st| discard_mapping[eq_mapping[*st]]).collect();

			




	
	
	
		
 

			




	
	
	
		
 
		return RegexpDFA{rules, end_states, alphabet_index: self.alphabet_index.clone()};

			




        

    



    


    



    



      

      





    
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