Deduplicate Edition enum

crates/parser/src/edition.rs

@@ -0,0 +1,55 @@
+//! The edition of the Rust language used in a crate.
+// Ideally this would be defined in the span crate, but the dependency chain is all over the place
+// wrt to span, parser and syntax.
+use std::fmt;
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash)]
+pub enum Edition {
+    Edition2015,
+    Edition2018,
+    Edition2021,
+    Edition2024,
+}
+
+impl Edition {
+    pub const CURRENT: Edition = Edition::Edition2021;
+    pub const DEFAULT: Edition = Edition::Edition2015;
+}
+
+#[derive(Debug)]
+pub struct ParseEditionError {
+    invalid_input: String,
+}
+
+impl std::error::Error for ParseEditionError {}
+impl fmt::Display for ParseEditionError {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        write!(f, "invalid edition: {:?}", self.invalid_input)
+    }
+}
+
+impl std::str::FromStr for Edition {
+    type Err = ParseEditionError;
+
+    fn from_str(s: &str) -> Result<Self, Self::Err> {
+        let res = match s {
+            "2015" => Edition::Edition2015,
+            "2018" => Edition::Edition2018,
+            "2021" => Edition::Edition2021,
+            "2024" => Edition::Edition2024,
+            _ => return Err(ParseEditionError { invalid_input: s.to_owned() }),
+        };
+        Ok(res)
+    }
+}
+
+impl fmt::Display for Edition {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        f.write_str(match self {
+            Edition::Edition2015 => "2015",
+            Edition::Edition2018 => "2018",
+            Edition::Edition2021 => "2021",
+            Edition::Edition2024 => "2024",
+        })
+    }
+}

crates/parser/src/lib.rs

@@ -26,6 +26,7 @@ extern crate ra_ap_rustc_lexer as rustc_lexer;
 #[cfg(feature = "in-rust-tree")]
 extern crate rustc_lexer;
 
+mod edition;
 mod event;
 mod grammar;
 mod input;
@@ -42,10 +43,10 @@ mod tests;
 pub(crate) use token_set::TokenSet;
 
 pub use crate::{
+    edition::Edition,
     input::Input,
     lexed_str::LexedStr,
     output::{Output, Step},
-    parser::Edition,
     shortcuts::StrStep,
     syntax_kind::SyntaxKind,
 };

crates/parser/src/parser.rs

@@ -8,6 +8,7 @@ use limit::Limit;
 use crate::{
     event::Event,
     input::Input,
+    Edition,
     SyntaxKind::{self, EOF, ERROR, TOMBSTONE},
     TokenSet, T,
 };
@@ -29,13 +30,6 @@ pub(crate) struct Parser<'t> {
     _edition: Edition,
 }
 
-#[non_exhaustive]
-pub enum Edition {
-    Edition2015,
-    Edition2018,
-    Edition2021,
-}
-
 static PARSER_STEP_LIMIT: Limit = Limit::new(15_000_000);
 
 impl<'t> Parser<'t> {