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use {SyntaxKind, TextUnit, Token};
use super::Event;
use super::super::is_insignificant;
use syntax_kinds::{ERROR, L_CURLY, R_CURLY};
use tree::{EOF, TOMBSTONE};
pub(crate) struct Marker {
pos: u32,
}
impl Marker {
pub fn complete(self, p: &mut Parser, kind: SyntaxKind) -> CompleteMarker {
match self.event(p) {
&mut Event::Start {
kind: ref mut slot, ..
} => {
*slot = kind;
}
_ => unreachable!(),
}
p.event(Event::Finish);
let result = CompleteMarker { pos: self.pos };
::std::mem::forget(self);
result
}
pub fn abandon(self, p: &mut Parser) {
let idx = self.pos as usize;
if idx == p.events.len() - 1 {
match p.events.pop() {
Some(Event::Start {
kind: TOMBSTONE,
forward_parent: None,
}) => (),
_ => unreachable!(),
}
}
::std::mem::forget(self);
}
fn event<'p>(&self, p: &'p mut Parser) -> &'p mut Event {
&mut p.events[self.idx()]
}
fn idx(&self) -> usize {
self.pos as usize
}
}
impl Drop for Marker {
fn drop(&mut self) {
if !::std::thread::panicking() {
panic!("Each marker should be eithe completed or abandoned");
}
}
}
pub(crate) struct CompleteMarker {
pos: u32,
}
impl CompleteMarker {
pub(crate) fn precede(self, p: &mut Parser) -> Marker {
let m = p.start();
match p.events[self.pos as usize] {
Event::Start {
ref mut forward_parent,
..
} => {
*forward_parent = Some(m.pos - self.pos);
}
_ => unreachable!(),
}
m
}
}
pub(crate) struct TokenSet {
pub tokens: &'static [SyntaxKind],
}
impl TokenSet {
pub fn contains(&self, kind: SyntaxKind) -> bool {
self.tokens.contains(&kind)
}
}
#[macro_export]
macro_rules! token_set {
($($t:ident),*) => {
TokenSet {
tokens: &[$($t),*],
}
};
($($t:ident),* ,) => {
token_set!($($t),*)
};
}
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>,
}
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 into_events(self) -> Vec<Event> {
assert!(self.curly_limit.is_none());
assert_eq!(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) -> Marker {
let m = Marker {
pos: self.events.len() as u32,
};
self.event(Event::Start {
kind: TOMBSTONE,
forward_parent: None,
});
m
}
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) {
let err = self.start();
while self.curly_level > old_level {
if self.bump() == EOF {
break;
}
}
err.complete(self, ERROR);
}
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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