rust/src/parser/input.rs

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use {lexer::Token, SyntaxKind, SyntaxKind::EOF, TextRange, TextUnit};
use std::ops::{Add, AddAssign};
pub(crate) struct ParserInput<'t> {
text: &'t str,
start_offsets: Vec<TextUnit>,
tokens: Vec<Token>, // non-whitespace tokens
}
impl<'t> ParserInput<'t> {
pub fn new(text: &'t str, raw_tokens: &'t [Token]) -> ParserInput<'t> {
let mut tokens = Vec::new();
let mut start_offsets = Vec::new();
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let mut len = 0.into();
for &token in raw_tokens.iter() {
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if !token.kind.is_trivia() {
tokens.push(token);
start_offsets.push(len);
}
len += token.len;
}
ParserInput {
text,
start_offsets,
tokens,
}
}
pub fn kind(&self, pos: InputPosition) -> SyntaxKind {
let idx = pos.0 as usize;
if !(idx < self.tokens.len()) {
return EOF;
}
self.tokens[idx].kind
}
#[allow(unused)]
pub fn text(&self, pos: InputPosition) -> &'t str {
let idx = pos.0 as usize;
if !(idx < self.tokens.len()) {
return "";
}
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let range = TextRange::offset_len(self.start_offsets[idx], self.tokens[idx].len);
&self.text[range]
}
}
#[derive(Copy, Clone, Ord, PartialOrd, Eq, PartialEq)]
pub(crate) struct InputPosition(u32);
impl InputPosition {
pub fn new() -> Self {
InputPosition(0)
}
}
impl Add<u32> for InputPosition {
type Output = InputPosition;
fn add(self, rhs: u32) -> InputPosition {
InputPosition(self.0 + rhs)
}
}
impl AddAssign<u32> for InputPosition {
fn add_assign(&mut self, rhs: u32) {
self.0 += rhs
}
}