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add doc comments

This commit is contained in:
Takayuki Maeda 2022-03-10 19:34:42 +09:00
parent 3ded25204b
commit 2db8236857
2 changed files with 14 additions and 5 deletions

View file

@ -156,6 +156,9 @@ impl AttemptLocalParseRecovery {
}
}
// SnapshotParser is used to create a snapshot of the parser
// without causing duplicate errors being emitted when the `Parser`
// is dropped.
pub(super) struct SnapshotParser<'a> {
parser: Parser<'a>,
unclosed_delims: Vec<UnmatchedBrace>,
@ -200,15 +203,21 @@ impl<'a> Parser<'a> {
&self.sess.span_diagnostic
}
pub(super) fn restore(&mut self, snapshot: SnapshotParser<'a>) {
/// Relace `self` with `snapshot.parser` and extend `unclosed_delims` with `snapshot.unclosed_delims`.
/// This is to avoid losing unclosed delims errors `create_snapshot_for_diagnostic` clears.
pub(super) fn restore_snapshot(&mut self, snapshot: SnapshotParser<'a>) {
*self = snapshot.parser;
self.unclosed_delims.extend(snapshot.unclosed_delims.clone());
}
pub(super) fn diagnostic_snapshot(&self) -> SnapshotParser<'a> {
/// Create a snapshot of the `Parser`.
pub(super) fn create_snapshot_for_diagnostic(&self) -> SnapshotParser<'a> {
let mut snapshot = self.clone();
let unclosed_delims = self.unclosed_delims.clone();
// initialize unclosed_delims to avoid duplicate errors.
// Clear `unclosed_delims` in snapshot to avoid
// duplicate errors being emitted when the `Parser`
// is dropped (which may or may not happen, depending
// if the parsing the snapshot is created for is successful)
snapshot.unclosed_delims.clear();
SnapshotParser { parser: snapshot, unclosed_delims }
}