dedupe expected tokens in ParseError

crates/codegen/runtime/cargo/src/runtime/language/parser_support/recovery.rs

@@ -90,10 +90,7 @@ impl ParserResult {
 
  let skipped = input.content(skipped_range.utf8());
 
- input.emit(ParseError {
- text_range: skipped_range,
- terminals_that_would_have_allowed_more_progress: expected_terminals.clone(),
- });
+ input.emit(ParseError::new(skipped_range, expected_terminals.clone()));
 
  ParserResult::SkippedUntil(SkippedUntil {
  nodes,

crates/codegen/runtime/cargo/src/runtime/language/parser_support/separated_helper.rs

@@ -62,11 +62,10 @@ impl SeparatedHelper {
  kind,
  input.content(skipped_range.utf8()),
  )));
- input.emit(ParseError {
- text_range: skipped_range,
- terminals_that_would_have_allowed_more_progress: incomplete
- .expected_terminals,
- });
+ input.emit(ParseError::new(
+ skipped_range,
+ incomplete.expected_terminals,
+ ));
 
  match lexer.parse_terminal_with_trivia::<LexCtx>(input, separator) {
  ParserResult::Match(r#match) => {

crates/codegen/runtime/cargo/src/runtime/parse_error/mod.rs

@@ -1,4 +1,3 @@
-use std::collections::BTreeSet;
 use std::fmt;
 
 use crate::diagnostic::{self, Diagnostic};
@@ -10,8 +9,8 @@ use crate::text_index::TextRange;
 /// This could have been caused by a syntax error, or by reaching the end of the file when more tokens were expected.
 #[derive(Debug, PartialEq, Eq, Clone)]
 pub struct ParseError {
- pub(crate) text_range: TextRange,
- pub(crate) terminals_that_would_have_allowed_more_progress: Vec<TerminalKind>,
+ text_range: TextRange,
+ terminals_that_would_have_allowed_more_progress: Vec<TerminalKind>,
 }
 
 impl ParseError {
@@ -29,8 +28,11 @@ impl ParseError {
 impl ParseError {
  pub(crate) fn new(
  text_range: TextRange,
- terminals_that_would_have_allowed_more_progress: Vec<TerminalKind>,
+ mut terminals_that_would_have_allowed_more_progress: Vec<TerminalKind>,
  ) -> Self {
+ terminals_that_would_have_allowed_more_progress.sort_unstable();
+ terminals_that_would_have_allowed_more_progress.dedup();
+
  Self {
  text_range,
  terminals_that_would_have_allowed_more_progress,
@@ -44,23 +46,22 @@ impl fmt::Display for ParseError {
  .terminals_that_would_have_allowed_more_progress
  .is_empty()
  {
- write!(f, "Expected end of file.")
- } else {
- let deduped = self
- .terminals_that_would_have_allowed_more_progress
- .iter()
- .collect::<BTreeSet<_>>();
+ return write!(f, "Expected end of file.");
+ }
 
-  write!(f, "Expected ")?;
+ let mut expected = self.terminals_that_would_have_allowed_more_progress.iter();
 
- for kind in deduped.iter().take(deduped.len() - 1) {
- write!(f, "{kind} or ")?;
- }
- let last = deduped.last().expect("we just checked that it's not empty");
- write!(f, "{last}.")?;
+ let first = expected
+ .next()
+ .expect("we just checked that it's not empty");
 
- Ok(())
+ write!(f, "Expected {first}")?;
+
+ for kind in expected {
+ write!(f, " or {kind}")?;
  }
+
+ write!(f, ".")
  }
 }