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use {Token, SyntaxKind, TextUnit};
use super::{Event};
use super::super::is_insignificant;
use syntax_kinds::{L_CURLY, R_CURLY, ERROR};
use tree::EOF;
pub(crate) struct Parser<'t> {
#[allow(unused)]
text: &'t str,
#[allow(unused)]
start_offsets: Vec<TextUnit>,
tokens: Vec<Token>, // non-whitespace tokens
pos: usize,
events: Vec<Event>,
curly_level: i32,
curly_limit: Option<i32>,
}
#[derive(Debug, Clone, Copy,PartialEq, Eq)]
pub(crate) struct Pos(u32);
#[derive(Debug, Clone, Copy,PartialEq, Eq)]
pub(crate) struct Mark(u32);
impl<'t> Parser<'t> {
pub(crate) fn new(text: &'t str, raw_tokens: &'t [Token]) -> Parser<'t> {
let mut tokens = Vec::new();
let mut start_offsets = Vec::new();
let mut len = TextUnit::new(0);
for &token in raw_tokens.iter() {
if !is_insignificant(token.kind) {
tokens.push(token);
start_offsets.push(len);
}
len += token.len;
}
Parser {
text,
start_offsets,
tokens,
pos: 0,
events: Vec::new(),
curly_level: 0,
curly_limit: None,
}
}
pub(crate) fn mark(&self) -> Mark {
Mark(self.events.len() as u32)
}
pub(crate) fn forward_parent(&mut self, child: Mark, parent: Mark) {
assert!(child.0 < parent.0);
let diff = parent.0 - child.0;
match self.events[child.0 as usize] {
Event::Start { ref mut forward_parent, .. } => {
*forward_parent = Some(diff);
}
_ => unreachable!()
}
}
pub(crate) fn pos(&self) -> Pos {
Pos(self.pos as u32)
}
pub(crate) fn into_events(self) -> Vec<Event> {
assert!(self.curly_limit.is_none());
assert!(self.current() == EOF);
self.events
}
pub(crate) fn current(&self) -> SyntaxKind {
if self.pos == self.tokens.len() {
return EOF;
}
let token = self.tokens[self.pos];
if let Some(limit) = self.curly_limit {
if limit == self.curly_level && token.kind == R_CURLY {
return EOF
}
}
token.kind
}
pub(crate) fn start(&mut self, kind: SyntaxKind) {
self.event(Event::Start { kind, forward_parent: None });
}
pub(crate) fn finish(&mut self) {
self.event(Event::Finish);
}
pub(crate) fn error<'p>(&'p mut self) -> ErrorBuilder<'p, 't> {
ErrorBuilder::new(self)
}
pub(crate) fn bump(&mut self) -> SyntaxKind {
let kind = self.current();
match kind {
L_CURLY => self.curly_level += 1,
R_CURLY => self.curly_level -= 1,
EOF => return EOF,
_ => (),
}
self.pos += 1;
self.event(Event::Token { kind, n_raw_tokens: 1 });
kind
}
pub(crate) fn raw_lookahead(&self, n: usize) -> SyntaxKind {
self.tokens.get(self.pos + n).map(|t| t.kind).unwrap_or(EOF)
}
pub(crate) fn curly_block<F: FnOnce(&mut Parser)>(&mut self, f: F) -> bool {
let old_level = self.curly_level;
let old_limit = self.curly_limit;
if !self.expect(L_CURLY) {
return false
}
self.curly_limit = Some(self.curly_level);
f(self);
assert!(self.curly_level > old_level);
self.curly_limit = old_limit;
if !self.expect(R_CURLY) {
self.start(ERROR);
while self.curly_level > old_level {
if self.bump() == EOF {
break;
}
}
self.finish();
}
true
}
fn event(&mut self, event: Event) {
self.events.push(event)
}
}
pub(crate) struct ErrorBuilder<'p, 't: 'p> {
message: Option<String>,
parser: &'p mut Parser<'t>
}
impl<'t, 'p> ErrorBuilder<'p, 't> {
fn new(parser: &'p mut Parser<'t>) -> Self {
ErrorBuilder { message: None, parser }
}
pub fn message<M: Into<String>>(mut self, m: M) -> Self {
self.message = Some(m.into());
self
}
pub fn emit(self) {
let message = self.message.expect("Error message not set");
self.parser.event(Event::Error { message });
}
}
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