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feat: Add support for converting regex_syntax::ast::Ast to NFA; D…
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…eprecate the old navie AST. (#9)
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@LinZhihao-723
LinZhihao-723 authored Dec 13, 2024
1 parent 67fd193 commit fd33c09
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Showing 13 changed files with 985 additions and 903 deletions.
175 changes: 47 additions & 128 deletions src/dfa/dfa.rs
View file
Original file line number Diff line number Diff line change
Expand Up @@ -2,7 +2,6 @@ use crate::nfa::nfa::NFA;
use std::collections::{HashMap, HashSet};
use std::hash::Hash;
use std::rc::Rc;
use std::sync::Arc;

#[derive(Clone, Debug, Eq, Hash, PartialEq)]
struct State(usize);
Expand Down Expand Up @@ -354,9 +353,11 @@ impl DfaSimulator {
#[cfg(test)]
mod tests {
use crate::dfa::dfa::{State, DFA};
use crate::error_handling::Result;
use crate::nfa::nfa::NFA;
use crate::parser::regex_parser::parser::RegexParser;
use crate::{dfa, nfa};
use std::collections::{HashMap, HashSet};
use std::collections::HashMap;
use std::rc::Rc;

#[test]
Expand Down Expand Up @@ -388,137 +389,44 @@ mod tests {
assert_eq!(dfa.simulate("ba"), (None, false));
}

#[cfg(test)]
fn create_nfa1() -> NFA {
// input NFA
// 0 -> 1 epsilon
// 0 -> 2 epsilon
// 1 -> 3 a
// 2 -> 4 a
// 3 -> 5 b
// 4 -> 6 epsilon
// 5 -> 6 epsilon
// 0: start state
// 6: accept state
fn create_nfa1() -> Result<NFA> {
// Should only match "a" or "ab"
let mut parser = RegexParser::new();
let parsed_ast = parser.parse_into_ast("(a)|(ab)")?;

let mut nfa = NFA::new(nfa::nfa::State(0), nfa::nfa::State(6));
let mut nfa = NFA::new();
nfa.add_ast_to_nfa(&parsed_ast, NFA::START_STATE, NFA::ACCEPT_STATE)?;

for i in 1..=6 {
nfa.test_extern_add_state(nfa::nfa::State(i));
}

nfa.test_extern_add_epsilon_transition(nfa::nfa::State(0), nfa::nfa::State(1));
nfa.test_extern_add_epsilon_transition(nfa::nfa::State(0), nfa::nfa::State(2));

nfa.test_extern_add_transition(nfa::nfa::Transition::new(
nfa::nfa::State(1),
nfa::nfa::State(3),
nfa::nfa::Transition::convert_char_to_symbol_onehot_encoding('a'),
-1,
));

nfa.test_extern_add_transition(nfa::nfa::Transition::new(
nfa::nfa::State(2),
nfa::nfa::State(4),
nfa::nfa::Transition::convert_char_to_symbol_onehot_encoding('a'),
-1,
));

nfa.test_extern_add_transition(nfa::nfa::Transition::new(
nfa::nfa::State(3),
nfa::nfa::State(5),
nfa::nfa::Transition::convert_char_to_symbol_onehot_encoding('b'),
-1,
));

nfa.test_extern_add_epsilon_transition(nfa::nfa::State(5), nfa::nfa::State(6));
nfa.test_extern_add_epsilon_transition(nfa::nfa::State(4), nfa::nfa::State(6));

nfa
Ok(nfa)
}

#[cfg(test)]
fn create_nfa2() -> NFA {
// input NFA
// 0 -> 1 epsilon
// 1 -> 1 c
// 1 -> 2 epsilon
fn create_nfa2() -> Result<NFA> {
// Should match "c*"
let mut parser = RegexParser::new();
let parsed_ast = parser.parse_into_ast("c*")?;

let mut nfa = NFA::new();
nfa.add_ast_to_nfa(&parsed_ast, NFA::START_STATE, NFA::ACCEPT_STATE)?;

let mut nfa = NFA::new(nfa::nfa::State(0), nfa::nfa::State(2));
nfa.test_extern_add_state(nfa::nfa::State(9));
nfa.test_extern_add_state(nfa::nfa::State(1));
nfa.test_extern_add_state(nfa::nfa::State(2));

nfa.test_extern_add_epsilon_transition(nfa::nfa::State(0), nfa::nfa::State(1));
nfa.test_extern_add_epsilon_transition(nfa::nfa::State(1), nfa::nfa::State(2));
nfa.test_extern_add_transition(nfa::nfa::Transition::new(
nfa::nfa::State(1),
nfa::nfa::State(1),
nfa::nfa::Transition::convert_char_to_symbol_onehot_encoding('c'),
-1,
));

nfa
Ok(nfa)
}

#[cfg(test)]
fn create_nfa3() -> NFA {
// input NFA
// 0 -> 1 epsilon
// 1 -> 2 c
// 2 -> 2 c
// 2 -> 3 a
// 3 -> 4 b
// 4 -> 5 epsilon
fn create_nfa3() -> crate::error_handling::Result<NFA> {
// Should match "c+ab"
let mut parser = RegexParser::new();
let parsed_ast = parser.parse_into_ast("c+ab")?;

let mut nfa = NFA::new(nfa::nfa::State(0), nfa::nfa::State(5));
for i in 1..=5 {
nfa.test_extern_add_state(nfa::nfa::State(i));
}
let mut nfa = NFA::new();
nfa.add_ast_to_nfa(&parsed_ast, NFA::START_STATE, NFA::ACCEPT_STATE)?;

nfa.test_extern_add_epsilon_transition(nfa::nfa::State(0), nfa::nfa::State(1));
nfa.test_extern_add_epsilon_transition(nfa::nfa::State(4), nfa::nfa::State(5));

nfa.test_extern_add_transition(nfa::nfa::Transition::new(
nfa::nfa::State(1),
nfa::nfa::State(2),
nfa::nfa::Transition::convert_char_to_symbol_onehot_encoding('c'),
-1,
));
nfa.test_extern_add_transition(nfa::nfa::Transition::new(
nfa::nfa::State(2),
nfa::nfa::State(2),
nfa::nfa::Transition::convert_char_to_symbol_onehot_encoding('c'),
-1,
));
nfa.test_extern_add_transition(nfa::nfa::Transition::new(
nfa::nfa::State(2),
nfa::nfa::State(3),
nfa::nfa::Transition::convert_char_to_symbol_onehot_encoding('a'),
-1,
));
nfa.test_extern_add_transition(nfa::nfa::Transition::new(
nfa::nfa::State(3),
nfa::nfa::State(4),
nfa::nfa::Transition::convert_char_to_symbol_onehot_encoding('b'),
-1,
));

nfa
Ok(nfa)
}

#[test]
fn test_nfa1_from_nfa_to_dfa() {
let nfa = create_nfa1();
fn test_nfa1_from_nfa_to_dfa() -> Result<()> {
let nfa = create_nfa1()?;
let dfa = DFA::from_multiple_nfas(vec![nfa]);

// 0 1 2 : 0
// 3 4 6 : 1
// 5 6 : 2

assert_eq!(dfa.start, dfa::dfa::State(0));
assert_eq!(dfa.accept.len(), 2);
assert_eq!(dfa.accept.contains(&State(1)), true);
Expand Down Expand Up @@ -550,11 +458,14 @@ mod tests {
assert_eq!(dfa.simulate("aa"), (None, false));
assert_eq!(dfa.simulate("abb"), (None, false));
assert_eq!(dfa.simulate("aba"), (None, false));

Ok(())
}

#[test]
fn test_nfa2_from_nfa_to_dfa() {
let nfa = create_nfa2();
fn test_nfa2_from_nfa_to_dfa() -> crate::error_handling::Result<()> {
let nfa = create_nfa2()?;
println!("{:?}", nfa);
let dfa = DFA::from_multiple_nfas(vec![nfa]);

// Check correctness given some examples
Expand All @@ -565,11 +476,13 @@ mod tests {
assert_eq!(dfa.simulate("ccccab"), (None, false));
assert_eq!(dfa.simulate("cab"), (None, false));
assert_eq!(dfa.simulate(""), (Some(0usize), true));

Ok(())
}

#[test]
fn test_nfa3_from_nfa_to_dfa() {
let nfa = create_nfa3();
fn test_nfa3_from_nfa_to_dfa() -> Result<()> {
let nfa = create_nfa3()?;
let dfa = DFA::from_multiple_nfas(vec![nfa]);

// Check correctness given some examples
Expand All @@ -581,13 +494,15 @@ mod tests {
assert_eq!(dfa.simulate("cab"), (Some(0usize), true));
assert_eq!(dfa.simulate("ab"), (None, false));
assert_eq!(dfa.simulate(""), (None, false));

Ok(())
}

#[test]
fn test_easy_from_multi_nfas_to_dfa() {
let nfa1 = create_nfa1();
let nfa2 = create_nfa2();
let nfa3 = create_nfa3();
fn test_easy_from_multi_nfas_to_dfa() -> Result<()> {
let nfa1 = create_nfa1()?;
let nfa2 = create_nfa2()?;
let nfa3 = create_nfa3()?;

let dfa = DFA::from_multiple_nfas(vec![nfa1, nfa2, nfa3]);

Expand All @@ -609,13 +524,15 @@ mod tests {
assert_eq!(dfa.simulate("cccccab"), (Some(2usize), true));
assert_eq!(dfa.simulate("cab"), (Some(2usize), true));
assert_eq!(dfa.simulate(""), (Some(1usize), true));

Ok(())
}

#[test]
fn test_esay_from_multi_nfas_to_dfa_single_char_simulation() {
let nfa1 = create_nfa1();
let nfa2 = create_nfa2();
let nfa3 = create_nfa3();
fn test_esay_from_multi_nfas_to_dfa_single_char_simulation() -> Result<()> {
let nfa1 = create_nfa1()?;
let nfa2 = create_nfa2()?;
let nfa3 = create_nfa3()?;

let dfa = DFA::from_multiple_nfas(vec![nfa1, nfa2, nfa3]);

Expand Down Expand Up @@ -660,5 +577,7 @@ mod tests {
(Some(1usize), true)
);
assert_eq!(dfa_simulator.simulate_single_char('b'), (None, false));

Ok(())
}
}
7 changes: 7 additions & 0 deletions src/error_handling/error.rs
View file
Original file line number Diff line number Diff line change
Expand Up @@ -3,6 +3,13 @@ use regex_syntax::ast;
#[derive(Debug)]
pub enum Error {
RegexParsingError(ast::Error),
UnsupportedAstNodeType(&'static str),
NoneASCIICharacters,
NegationNotSupported(&'static str),
NonGreedyRepetitionNotSupported,
UnsupportedAstBracketedKind,
UnsupportedClassSetType,
UnsupportedGroupKindType,
}

pub type Result<T> = std::result::Result<T, Error>;
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