tree-sitter/cli/src/generate/nfa.rs
2024-02-06 23:34:14 -05:00

1076 lines
36 KiB
Rust

use std::char;
use std::cmp::max;
use std::cmp::Ordering;
use std::collections::HashSet;
use std::fmt;
use std::mem::swap;
use std::ops::Range;
/// A set of characters represented as a vector of ranges.
#[derive(Clone, PartialEq, Eq, Hash)]
pub struct CharacterSet {
ranges: Vec<Range<u32>>,
}
/// A state in an NFA representing a regular grammar.
#[derive(Debug, PartialEq, Eq)]
pub enum NfaState {
Advance {
chars: CharacterSet,
state_id: u32,
is_sep: bool,
precedence: i32,
},
Split(u32, u32),
Accept {
variable_index: usize,
precedence: i32,
},
}
#[derive(PartialEq, Eq, Default)]
pub struct Nfa {
pub states: Vec<NfaState>,
}
#[derive(Debug)]
pub struct NfaCursor<'a> {
pub(crate) state_ids: Vec<u32>,
nfa: &'a Nfa,
}
#[derive(Debug, PartialEq, Eq)]
pub struct NfaTransition {
pub characters: CharacterSet,
pub is_separator: bool,
pub precedence: i32,
pub states: Vec<u32>,
}
const END: u32 = char::MAX as u32 + 1;
impl CharacterSet {
/// Create a character set with a single character.
pub const fn empty() -> Self {
Self { ranges: Vec::new() }
}
/// Create a character set with a given *inclusive* range of characters.
#[allow(clippy::single_range_in_vec_init)]
pub fn from_range(mut first: char, mut last: char) -> Self {
if first > last {
swap(&mut first, &mut last);
}
Self {
ranges: vec![(first as u32)..(last as u32 + 1)],
}
}
/// Create a character set with a single character.
#[allow(clippy::single_range_in_vec_init)]
pub fn from_char(c: char) -> Self {
Self {
ranges: vec![(c as u32)..(c as u32 + 1)],
}
}
/// Create a character set containing all characters *not* present
/// in this character set.
pub fn negate(mut self) -> Self {
let mut i = 0;
let mut previous_end = 0;
while i < self.ranges.len() {
let range = &mut self.ranges[i];
let start = previous_end;
previous_end = range.end;
if start < range.start {
self.ranges[i] = start..range.start;
i += 1;
} else {
self.ranges.remove(i);
}
}
if previous_end < END {
self.ranges.push(previous_end..END);
}
self
}
pub fn add_char(mut self, c: char) -> Self {
self.add_int_range(0, c as u32, c as u32 + 1);
self
}
pub fn add_range(mut self, start: char, end: char) -> Self {
self.add_int_range(0, start as u32, end as u32 + 1);
self
}
pub fn add(mut self, other: &Self) -> Self {
let mut index = 0;
for range in &other.ranges {
index = self.add_int_range(index, range.start, range.end);
}
self
}
fn add_int_range(&mut self, mut i: usize, start: u32, end: u32) -> usize {
while i < self.ranges.len() {
let range = &mut self.ranges[i];
if range.start > end {
self.ranges.insert(i, start..end);
return i;
}
if range.end >= start {
range.end = range.end.max(end);
range.start = range.start.min(start);
// Join this range with the next range if needed.
while i + 1 < self.ranges.len() && self.ranges[i + 1].start <= self.ranges[i].end {
self.ranges[i].end = self.ranges[i].end.max(self.ranges[i + 1].end);
self.ranges.remove(i + 1);
}
return i;
}
i += 1;
}
self.ranges.push(start..end);
i
}
pub fn does_intersect(&self, other: &Self) -> bool {
let mut left_ranges = self.ranges.iter();
let mut right_ranges = other.ranges.iter();
let mut left_range = left_ranges.next();
let mut right_range = right_ranges.next();
while let (Some(left), Some(right)) = (&left_range, &right_range) {
if left.end <= right.start {
left_range = left_ranges.next();
} else if left.start >= right.end {
right_range = right_ranges.next();
} else {
return true;
}
}
false
}
/// Get the set of characters that are present in both this set
/// and the other set. Remove those common characters from both
/// of the operands.
pub fn remove_intersection(&mut self, other: &mut Self) -> Self {
let mut intersection = Vec::new();
let mut left_i = 0;
let mut right_i = 0;
while left_i < self.ranges.len() && right_i < other.ranges.len() {
let left = &mut self.ranges[left_i];
let right = &mut other.ranges[right_i];
match left.start.cmp(&right.start) {
Ordering::Less => {
// [ L ]
// [ R ]
if left.end <= right.start {
left_i += 1;
continue;
}
match left.end.cmp(&right.end) {
// [ L ]
// [ R ]
Ordering::Less => {
intersection.push(right.start..left.end);
swap(&mut left.end, &mut right.start);
left_i += 1;
}
// [ L ]
// [ R ]
Ordering::Equal => {
intersection.push(right.clone());
left.end = right.start;
other.ranges.remove(right_i);
}
// [ L ]
// [ R ]
Ordering::Greater => {
intersection.push(right.clone());
let new_range = left.start..right.start;
left.start = right.end;
self.ranges.insert(left_i, new_range);
other.ranges.remove(right_i);
left_i += 1;
}
}
}
// [ L ]
// [ R ]
Ordering::Equal if left.end < right.end => {
intersection.push(left.start..left.end);
right.start = left.end;
self.ranges.remove(left_i);
}
// [ L ]
// [ R ]
Ordering::Equal if left.end == right.end => {
intersection.push(left.clone());
self.ranges.remove(left_i);
other.ranges.remove(right_i);
}
// [ L ]
// [ R ]
Ordering::Equal if left.end > right.end => {
intersection.push(right.clone());
left.start = right.end;
other.ranges.remove(right_i);
}
Ordering::Equal => {}
Ordering::Greater => {
// [ L ]
// [ R ]
if left.start >= right.end {
right_i += 1;
continue;
}
match left.end.cmp(&right.end) {
// [ L ]
// [ R ]
Ordering::Less => {
intersection.push(left.clone());
let new_range = right.start..left.start;
right.start = left.end;
other.ranges.insert(right_i, new_range);
self.ranges.remove(left_i);
right_i += 1;
}
// [ L ]
// [ R ]
Ordering::Equal => {
intersection.push(left.clone());
right.end = left.start;
self.ranges.remove(left_i);
}
// [ L ]
// [ R ]
Ordering::Greater => {
intersection.push(left.start..right.end);
swap(&mut left.start, &mut right.end);
right_i += 1;
}
}
}
}
}
Self {
ranges: intersection,
}
}
/// Produces a `CharacterSet` containing every character in `self` that is not present in
/// `other`.
pub fn difference(mut self, mut other: Self) -> Self {
self.remove_intersection(&mut other);
self
}
/// Produces a `CharacterSet` containing every character that is in _exactly one_ of `self` or
/// `other`, but is not present in both sets.
pub fn symmetric_difference(mut self, mut other: Self) -> Self {
self.remove_intersection(&mut other);
self.add(&other)
}
pub fn iter(&self) -> impl Iterator<Item = u32> + '_ {
self.ranges.iter().flat_map(std::clone::Clone::clone)
}
pub fn chars(&self) -> impl Iterator<Item = char> + '_ {
self.iter().filter_map(char::from_u32)
}
pub fn is_empty(&self) -> bool {
self.ranges.is_empty()
}
/// Get a reduced list of character ranges, assuming that a given
/// set of characters can be safely ignored.
pub fn simplify_ignoring<'a>(
&'a self,
ruled_out_characters: &'a HashSet<u32>,
) -> Vec<Range<char>> {
let mut prev_range: Option<Range<char>> = None;
self.chars()
.map(|c| (c, false))
.chain(Some(('\0', true)))
.filter_map(move |(c, done)| {
if done {
return prev_range.clone();
}
if ruled_out_characters.contains(&(c as u32)) {
return None;
}
if let Some(range) = prev_range.clone() {
let mut prev_range_successor = range.end as u32 + 1;
while prev_range_successor < c as u32 {
if !ruled_out_characters.contains(&prev_range_successor) {
prev_range = Some(c..c);
return Some(range);
}
prev_range_successor += 1;
}
prev_range = Some(range.start..c);
} else {
prev_range = Some(c..c);
}
None
})
.collect()
}
pub fn contains(&self, c: char) -> bool {
self.ranges.iter().any(|r| r.contains(&(c as u32)))
}
}
impl Ord for CharacterSet {
fn cmp(&self, other: &Self) -> Ordering {
let count_cmp = self
.ranges
.iter()
.map(std::iter::ExactSizeIterator::len)
.sum::<usize>()
.cmp(
&other
.ranges
.iter()
.map(std::iter::ExactSizeIterator::len)
.sum(),
);
if count_cmp != Ordering::Equal {
return count_cmp;
}
for (left_range, right_range) in self.ranges.iter().zip(other.ranges.iter()) {
let cmp = left_range.len().cmp(&right_range.len());
if cmp != Ordering::Equal {
return cmp;
}
for (left, right) in left_range.clone().zip(right_range.clone()) {
let cmp = left.cmp(&right);
if cmp != Ordering::Equal {
return cmp;
}
}
}
Ordering::Equal
}
}
impl PartialOrd for CharacterSet {
fn partial_cmp(&self, other: &Self) -> Option<Ordering> {
Some(self.cmp(other))
}
}
impl fmt::Debug for CharacterSet {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
write!(f, "CharacterSet [")?;
let mut set = self.clone();
if self.contains(char::MAX) {
write!(f, "^ ")?;
set = set.negate();
}
for (i, c) in set.chars().enumerate() {
if i > 0 {
write!(f, ", ")?;
}
write!(f, "{c:?}")?;
}
write!(f, "]")?;
Ok(())
}
}
impl Nfa {
pub const fn new() -> Self {
Self { states: Vec::new() }
}
pub fn last_state_id(&self) -> u32 {
self.states.len() as u32 - 1
}
}
impl fmt::Debug for Nfa {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
writeln!(f, "Nfa {{ states: {{")?;
for (i, state) in self.states.iter().enumerate() {
writeln!(f, " {i}: {state:?},")?;
}
write!(f, "}} }}")?;
Ok(())
}
}
impl<'a> NfaCursor<'a> {
pub fn new(nfa: &'a Nfa, mut states: Vec<u32>) -> Self {
let mut result = Self {
nfa,
state_ids: Vec::new(),
};
result.add_states(&mut states);
result
}
pub fn reset(&mut self, mut states: Vec<u32>) {
self.state_ids.clear();
self.add_states(&mut states);
}
pub fn force_reset(&mut self, states: Vec<u32>) {
self.state_ids = states;
}
pub fn transition_chars(&self) -> impl Iterator<Item = (&CharacterSet, bool)> {
self.raw_transitions().map(|t| (t.0, t.1))
}
pub fn transitions(&self) -> Vec<NfaTransition> {
Self::group_transitions(self.raw_transitions())
}
fn raw_transitions(&self) -> impl Iterator<Item = (&CharacterSet, bool, i32, u32)> {
self.state_ids.iter().filter_map(move |id| {
if let NfaState::Advance {
chars,
state_id,
precedence,
is_sep,
} = &self.nfa.states[*id as usize]
{
Some((chars, *is_sep, *precedence, *state_id))
} else {
None
}
})
}
fn group_transitions<'b>(
iter: impl Iterator<Item = (&'b CharacterSet, bool, i32, u32)>,
) -> Vec<NfaTransition> {
let mut result: Vec<NfaTransition> = Vec::new();
for (chars, is_sep, prec, state) in iter {
let mut chars = chars.clone();
let mut i = 0;
while i < result.len() && !chars.is_empty() {
let intersection = result[i].characters.remove_intersection(&mut chars);
if !intersection.is_empty() {
let mut intersection_states = result[i].states.clone();
if let Err(j) = intersection_states.binary_search(&state) {
intersection_states.insert(j, state);
}
let intersection_transition = NfaTransition {
characters: intersection,
is_separator: result[i].is_separator && is_sep,
precedence: max(result[i].precedence, prec),
states: intersection_states,
};
if result[i].characters.is_empty() {
result[i] = intersection_transition;
} else {
result.insert(i, intersection_transition);
i += 1;
}
}
i += 1;
}
if !chars.is_empty() {
result.push(NfaTransition {
characters: chars,
precedence: prec,
states: vec![state],
is_separator: is_sep,
});
}
}
result.sort_unstable_by(|a, b| a.characters.cmp(&b.characters));
let mut i = 0;
'i_loop: while i < result.len() {
for j in 0..i {
if result[j].states == result[i].states
&& result[j].is_separator == result[i].is_separator
&& result[j].precedence == result[i].precedence
{
let mut characters = CharacterSet::empty();
swap(&mut characters, &mut result[j].characters);
result[j].characters = characters.add(&result[i].characters);
result.remove(i);
continue 'i_loop;
}
}
i += 1;
}
result
}
pub fn completions(&self) -> impl Iterator<Item = (usize, i32)> + '_ {
self.state_ids.iter().filter_map(move |state_id| {
if let NfaState::Accept {
variable_index,
precedence,
} = self.nfa.states[*state_id as usize]
{
Some((variable_index, precedence))
} else {
None
}
})
}
pub fn add_states(&mut self, new_state_ids: &mut Vec<u32>) {
let mut i = 0;
while i < new_state_ids.len() {
let state_id = new_state_ids[i];
let state = &self.nfa.states[state_id as usize];
if let NfaState::Split(left, right) = state {
let mut has_left = false;
let mut has_right = false;
for new_state_id in new_state_ids.iter() {
if *new_state_id == *left {
has_left = true;
}
if *new_state_id == *right {
has_right = true;
}
}
if !has_left {
new_state_ids.push(*left);
}
if !has_right {
new_state_ids.push(*right);
}
} else if let Err(i) = self.state_ids.binary_search(&state_id) {
self.state_ids.insert(i, state_id);
}
i += 1;
}
}
}
#[cfg(test)]
mod tests {
use super::*;
#[test]
fn test_adding_ranges() {
let mut set = CharacterSet::empty()
.add_range('c', 'm')
.add_range('q', 's');
// within existing range
set = set.add_char('d');
assert_eq!(
set,
CharacterSet::empty()
.add_range('c', 'm')
.add_range('q', 's')
);
// at end of existing range
set = set.add_char('m');
assert_eq!(
set,
CharacterSet::empty()
.add_range('c', 'm')
.add_range('q', 's')
);
// adjacent to end of existing range
set = set.add_char('n');
assert_eq!(
set,
CharacterSet::empty()
.add_range('c', 'n')
.add_range('q', 's')
);
// filling gap between existing ranges
set = set.add_range('o', 'p');
assert_eq!(set, CharacterSet::empty().add_range('c', 's'));
set = CharacterSet::empty()
.add_range('c', 'f')
.add_range('i', 'l')
.add_range('n', 'r');
set = set.add_range('d', 'o');
assert_eq!(set, CharacterSet::empty().add_range('c', 'r'));
}
#[test]
fn test_adding_sets() {
let set1 = CharacterSet::empty()
.add_range('c', 'f')
.add_range('i', 'l');
let set2 = CharacterSet::empty().add_range('b', 'g').add_char('h');
assert_eq!(
set1.add(&set2),
CharacterSet::empty()
.add_range('b', 'g')
.add_range('h', 'l')
);
}
#[test]
fn test_group_transitions() {
let table = [
// overlapping character classes
(
vec![
(CharacterSet::empty().add_range('a', 'f'), false, 0, 1),
(CharacterSet::empty().add_range('d', 'i'), false, 1, 2),
],
vec![
NfaTransition {
characters: CharacterSet::empty().add_range('a', 'c'),
is_separator: false,
precedence: 0,
states: vec![1],
},
NfaTransition {
characters: CharacterSet::empty().add_range('d', 'f'),
is_separator: false,
precedence: 1,
states: vec![1, 2],
},
NfaTransition {
characters: CharacterSet::empty().add_range('g', 'i'),
is_separator: false,
precedence: 1,
states: vec![2],
},
],
),
// large character class followed by many individual characters
(
vec![
(CharacterSet::empty().add_range('a', 'z'), false, 0, 1),
(CharacterSet::empty().add_char('d'), false, 0, 2),
(CharacterSet::empty().add_char('i'), false, 0, 3),
(CharacterSet::empty().add_char('f'), false, 0, 4),
],
vec![
NfaTransition {
characters: CharacterSet::empty().add_char('d'),
is_separator: false,
precedence: 0,
states: vec![1, 2],
},
NfaTransition {
characters: CharacterSet::empty().add_char('f'),
is_separator: false,
precedence: 0,
states: vec![1, 4],
},
NfaTransition {
characters: CharacterSet::empty().add_char('i'),
is_separator: false,
precedence: 0,
states: vec![1, 3],
},
NfaTransition {
characters: CharacterSet::empty()
.add_range('a', 'c')
.add_char('e')
.add_range('g', 'h')
.add_range('j', 'z'),
is_separator: false,
precedence: 0,
states: vec![1],
},
],
),
// negated character class followed by an individual character
(
vec![
(CharacterSet::empty().add_char('0'), false, 0, 1),
(CharacterSet::empty().add_char('b'), false, 0, 2),
(
CharacterSet::empty().add_range('a', 'f').negate(),
false,
0,
3,
),
(CharacterSet::empty().add_char('c'), false, 0, 4),
],
vec![
NfaTransition {
characters: CharacterSet::empty().add_char('0'),
precedence: 0,
states: vec![1, 3],
is_separator: false,
},
NfaTransition {
characters: CharacterSet::empty().add_char('b'),
precedence: 0,
states: vec![2],
is_separator: false,
},
NfaTransition {
characters: CharacterSet::empty().add_char('c'),
precedence: 0,
states: vec![4],
is_separator: false,
},
NfaTransition {
characters: CharacterSet::empty()
.add_range('a', 'f')
.add_char('0')
.negate(),
precedence: 0,
states: vec![3],
is_separator: false,
},
],
),
// multiple negated character classes
(
vec![
(CharacterSet::from_char('a'), false, 0, 1),
(CharacterSet::from_range('a', 'c').negate(), false, 0, 2),
(CharacterSet::from_char('g'), false, 0, 6),
(CharacterSet::from_range('d', 'f').negate(), false, 0, 3),
(CharacterSet::from_range('g', 'i').negate(), false, 0, 4),
(CharacterSet::from_char('g'), false, 0, 5),
],
vec![
NfaTransition {
characters: CharacterSet::from_char('a'),
precedence: 0,
states: vec![1, 3, 4],
is_separator: false,
},
NfaTransition {
characters: CharacterSet::from_char('g'),
precedence: 0,
states: vec![2, 3, 5, 6],
is_separator: false,
},
NfaTransition {
characters: CharacterSet::from_range('b', 'c'),
precedence: 0,
states: vec![3, 4],
is_separator: false,
},
NfaTransition {
characters: CharacterSet::from_range('h', 'i'),
precedence: 0,
states: vec![2, 3],
is_separator: false,
},
NfaTransition {
characters: CharacterSet::from_range('d', 'f'),
precedence: 0,
states: vec![2, 4],
is_separator: false,
},
NfaTransition {
characters: CharacterSet::from_range('a', 'i').negate(),
precedence: 0,
states: vec![2, 3, 4],
is_separator: false,
},
],
),
// disjoint characters with same state
(
vec![
(CharacterSet::from_char('a'), false, 0, 1),
(CharacterSet::from_char('b'), false, 0, 2),
(CharacterSet::from_char('c'), false, 0, 1),
(CharacterSet::from_char('d'), false, 0, 1),
(CharacterSet::from_char('e'), false, 0, 2),
],
vec![
NfaTransition {
characters: CharacterSet::empty().add_char('a').add_range('c', 'd'),
precedence: 0,
states: vec![1],
is_separator: false,
},
NfaTransition {
characters: CharacterSet::empty().add_char('b').add_char('e'),
precedence: 0,
states: vec![2],
is_separator: false,
},
],
),
];
for (i, row) in table.iter().enumerate() {
assert_eq!(
NfaCursor::group_transitions(
row.0
.iter()
.map(|(chars, is_sep, prec, state)| (chars, *is_sep, *prec, *state))
),
row.1,
"row {i}",
);
}
}
#[test]
fn test_character_set_intersection_difference_ops() {
struct Row {
left: CharacterSet,
right: CharacterSet,
left_only: CharacterSet,
right_only: CharacterSet,
intersection: CharacterSet,
}
let rows = [
// [ L ]
// [ R ]
Row {
left: CharacterSet::from_range('a', 'f'),
right: CharacterSet::from_range('g', 'm'),
left_only: CharacterSet::from_range('a', 'f'),
right_only: CharacterSet::from_range('g', 'm'),
intersection: CharacterSet::empty(),
},
// [ L ]
// [ R ]
Row {
left: CharacterSet::from_range('a', 'f'),
right: CharacterSet::from_range('c', 'i'),
left_only: CharacterSet::from_range('a', 'b'),
right_only: CharacterSet::from_range('g', 'i'),
intersection: CharacterSet::from_range('c', 'f'),
},
// [ L ]
// [ R ]
Row {
left: CharacterSet::from_range('a', 'f'),
right: CharacterSet::from_range('d', 'f'),
left_only: CharacterSet::from_range('a', 'c'),
right_only: CharacterSet::empty(),
intersection: CharacterSet::from_range('d', 'f'),
},
// [ L ]
// [ R ]
Row {
left: CharacterSet::from_range('a', 'm'),
right: CharacterSet::from_range('d', 'f'),
left_only: CharacterSet::empty()
.add_range('a', 'c')
.add_range('g', 'm'),
right_only: CharacterSet::empty(),
intersection: CharacterSet::from_range('d', 'f'),
},
// [ L ]
// [R]
Row {
left: CharacterSet::from_range(',', '/'),
right: CharacterSet::from_char('/'),
left_only: CharacterSet::from_range(',', '.'),
right_only: CharacterSet::empty(),
intersection: CharacterSet::from_char('/'),
},
// [ L ]
// [R]
Row {
left: CharacterSet::from_range(',', '/'),
right: CharacterSet::from_char('/'),
left_only: CharacterSet::from_range(',', '.'),
right_only: CharacterSet::empty(),
intersection: CharacterSet::from_char('/'),
},
// [ L1 ] [ L2 ]
// [ R ]
Row {
left: CharacterSet::empty()
.add_range('a', 'e')
.add_range('h', 'l'),
right: CharacterSet::from_range('c', 'i'),
left_only: CharacterSet::empty()
.add_range('a', 'b')
.add_range('j', 'l'),
right_only: CharacterSet::from_range('f', 'g'),
intersection: CharacterSet::empty()
.add_range('c', 'e')
.add_range('h', 'i'),
},
];
for (i, row) in rows.iter().enumerate() {
let mut left = row.left.clone();
let mut right = row.right.clone();
assert_eq!(
left.remove_intersection(&mut right),
row.intersection,
"row {}a: {:?} && {:?}",
i,
row.left,
row.right
);
assert_eq!(
left, row.left_only,
"row {}a: {:?} - {:?}",
i, row.left, row.right
);
assert_eq!(
right, row.right_only,
"row {}a: {:?} - {:?}",
i, row.right, row.left
);
let mut left = row.left.clone();
let mut right = row.right.clone();
assert_eq!(
right.remove_intersection(&mut left),
row.intersection,
"row {}b: {:?} && {:?}",
i,
row.left,
row.right
);
assert_eq!(
left, row.left_only,
"row {}b: {:?} - {:?}",
i, row.left, row.right
);
assert_eq!(
right, row.right_only,
"row {}b: {:?} - {:?}",
i, row.right, row.left
);
assert_eq!(
row.left.clone().difference(row.right.clone()),
row.left_only,
"row {}b: {:?} -- {:?}",
i,
row.left,
row.right
);
let symm_difference = row.left_only.clone().add(&row.right_only);
assert_eq!(
row.left.clone().symmetric_difference(row.right.clone()),
symm_difference,
"row {i}b: {:?} ~~ {:?}",
row.left,
row.right
);
}
}
#[test]
fn test_character_set_does_intersect() {
let (a, b) = (CharacterSet::empty(), CharacterSet::empty());
assert!(!a.does_intersect(&b));
assert!(!b.does_intersect(&a));
let (a, b) = (
CharacterSet::empty().add_char('a'),
CharacterSet::empty().add_char('a'),
);
assert!(a.does_intersect(&b));
assert!(b.does_intersect(&a));
let (a, b) = (
CharacterSet::empty().add_char('b'),
CharacterSet::empty().add_char('a').add_char('c'),
);
assert!(!a.does_intersect(&b));
assert!(!b.does_intersect(&a));
let (a, b) = (
CharacterSet::from_char('b'),
CharacterSet::from_range('a', 'c'),
);
assert!(a.does_intersect(&b));
assert!(b.does_intersect(&a));
let (a, b) = (
CharacterSet::from_char('b'),
CharacterSet::from_range('a', 'c').negate(),
);
assert!(!a.does_intersect(&b));
assert!(!b.does_intersect(&a));
let (a, b) = (
CharacterSet::from_char('a').negate(),
CharacterSet::from_char('a').negate(),
);
assert!(a.does_intersect(&b));
assert!(b.does_intersect(&a));
let (a, b) = (
CharacterSet::from_char('c'),
CharacterSet::from_char('a').negate(),
);
assert!(a.does_intersect(&b));
assert!(b.does_intersect(&a));
let (a, b) = (
CharacterSet::from_range('c', 'f'),
CharacterSet::from_char('f'),
);
assert!(a.does_intersect(&b));
assert!(b.does_intersect(&a));
}
#[test]
#[allow(clippy::single_range_in_vec_init)]
fn test_character_set_get_ranges() {
struct Row {
chars: Vec<char>,
ruled_out_chars: Vec<char>,
expected_ranges: Vec<Range<char>>,
}
let table = [
Row {
chars: vec!['a'],
ruled_out_chars: vec![],
expected_ranges: vec!['a'..'a'],
},
Row {
chars: vec!['a', 'b', 'c', 'e', 'z'],
ruled_out_chars: vec![],
expected_ranges: vec!['a'..'c', 'e'..'e', 'z'..'z'],
},
Row {
chars: vec!['a', 'b', 'c', 'e', 'h', 'z'],
ruled_out_chars: vec!['d', 'f', 'g'],
expected_ranges: vec!['a'..'h', 'z'..'z'],
},
];
for Row {
chars,
ruled_out_chars,
expected_ranges,
} in &table
{
let ruled_out_chars = ruled_out_chars.iter().map(|c: &char| *c as u32).collect();
let mut set = CharacterSet::empty();
for c in chars {
set = set.add_char(*c);
}
let ranges = set.simplify_ignoring(&ruled_out_chars);
assert_eq!(ranges, *expected_ranges);
}
}
}