Shrink ra_parser::Event from 32 bytes to 16 bytes

This boxes the Error variant with the assumption that it is rarely constructed

crates/ra_parser/src/lib.rs

@@ -25,7 +25,7 @@ pub(crate) use token_set::TokenSet;
 pub use syntax_kind::SyntaxKind;
 
 #[derive(Debug, Clone, PartialEq, Eq, Hash)]
-pub struct ParseError(pub String);
+pub struct ParseError(pub Box<String>);
 
 /// `TokenSource` abstracts the source of the tokens parser operates on.
 ///

crates/ra_parser/src/parser.rs

@@ -192,7 +192,7 @@ impl<'t> Parser<'t> {
     /// structured errors with spans and notes, like rustc
     /// does.
     pub(crate) fn error<T: Into<String>>(&mut self, message: T) {
-        let msg = ParseError(message.into());
+        let msg = ParseError(Box::new(message.into()));
         self.push_event(Event::Error { msg })
     }
 

crates/ra_syntax/src/syntax_node.rs

@@ -70,6 +70,6 @@ impl SyntaxTreeBuilder {
     }
 
     pub fn error(&mut self, error: ra_parser::ParseError, text_pos: TextSize) {
-        self.errors.push(SyntaxError::new_at_offset(error.0, text_pos))
+        self.errors.push(SyntaxError::new_at_offset(*error.0, text_pos))
     }
 }