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use rustc_hash::FxHashMap;
use super::pos::*;
use crate::swc::parser::token::TokenAndSpan;
pub struct TokenContainer<'a> {
pub tokens: &'a [TokenAndSpan],
start_to_index: FxHashMap<SourcePos, usize>,
end_to_index: FxHashMap<SourcePos, usize>,
}
impl<'a> TokenContainer<'a> {
pub fn new(tokens: &'a [TokenAndSpan]) -> Self {
TokenContainer {
tokens,
start_to_index: tokens.iter().enumerate().map(|(i, token)| (token.start(), i)).collect(),
end_to_index: tokens.iter().enumerate().map(|(i, token)| (token.end(), i)).collect(),
}
}
pub fn get_token_index_at_start(&self, start: SourcePos) -> Option<usize> {
self.start_to_index.get(&start).copied()
}
pub fn get_token_index_at_end(&self, end: SourcePos) -> Option<usize> {
self.end_to_index.get(&end).copied()
}
pub fn get_token_at_index(&self, index: usize) -> Option<&TokenAndSpan> {
self.tokens.get(index)
}
pub fn get_tokens_in_range(&self, start: SourcePos, end: SourcePos) -> &'a [TokenAndSpan] {
let start_index = self.get_leftmost_token_index(start);
let end_index = self.get_rightmost_token_index(end);
let start_index = start_index.unwrap_or_else(|| end_index.unwrap_or(0));
let end_index = end_index.map(|i| i + 1).unwrap_or(start_index);
&self.tokens[start_index..end_index]
}
fn get_leftmost_token_index(&self, start: SourcePos) -> Option<usize> {
if let Some(&start_index) = self.start_to_index.get(&start) {
Some(start_index)
} else if let Some(&start_index) = self.end_to_index.get(&start) {
Some(start_index + 1)
} else {
for (i, token) in self.tokens.iter().enumerate() {
if token.start() >= start {
return Some(i);
}
}
None
}
}
fn get_rightmost_token_index(&self, end: SourcePos) -> Option<usize> {
if let Some(&end_index) = self.end_to_index.get(&end) {
Some(end_index)
} else if let Some(&end_index) = self.start_to_index.get(&end) {
if end_index > 0 {
Some(end_index - 1)
} else {
None
}
} else {
for (i, token) in self.tokens.iter().enumerate().rev() {
if token.end() <= end {
return Some(i);
}
}
None
}
}
pub fn get_previous_token(&self, start: SourcePos) -> Option<&TokenAndSpan> {
let index = self.start_to_index.get(&start);
if let Some(&index) = index {
if index == 0 {
None
} else {
Some(&self.tokens[index - 1])
}
} else {
let mut last_token = None;
for token in self.tokens {
if token.end() > start {
return last_token;
} else {
last_token = Some(token);
}
}
None
}
}
pub fn get_next_token(&self, end: SourcePos) -> Option<&TokenAndSpan> {
if let Some(index) = self.end_to_index.get(&end) {
self.tokens.get(index + 1)
} else {
for token in self.tokens {
if token.start() > end {
return Some(token);
}
}
None
}
}
}
#[cfg(test)]
mod test {
use std::path::PathBuf;
use super::super::pos::SourcePos;
use super::TokenContainer;
use crate::common::SourceRangedForSpanned;
use crate::test_helpers::*;
#[test]
fn get_next_token() {
let (_, tokens, _, _) = get_swc_module(&PathBuf::from("path.js"), r#"let /* a */ a = 5;"#);
let token_container = TokenContainer::new(&tokens);
assert_eq!(token_container.get_next_token(SourcePos::new(0)).unwrap().start(), SourcePos::new(12));
assert_eq!(token_container.get_next_token(SourcePos::new(3)).unwrap().start(), SourcePos::new(12));
assert_eq!(token_container.get_next_token(SourcePos::new(5)).unwrap().start(), SourcePos::new(12));
assert_eq!(token_container.get_next_token(SourcePos::new(11)).unwrap().start(), SourcePos::new(12));
assert_eq!(token_container.get_next_token(SourcePos::new(18)), None);
}
}