1 files changed, 62 insertions, 0 deletions
diff --git a/src/gen/rust/ident.rs b/src/gen/rust/ident.rs
new file mode 100644
index 0000000..df1d1f0
--- /dev/null
+++ b/src/gen/rust/ident.rs
@@ -0,0 +1,62 @@
+use std::fmt;
+
+use crate::gen::rust::ident_with_path::RustIdentWithPath;
+use crate::gen::rust::keywords::is_rust_keyword;
+use crate::gen::rust::rel_path::RustRelativePath;
+
+/// Valid Rust identifier
+#[derive(Eq, PartialEq, Debug, Clone, Hash)]
+pub(crate) struct RustIdent(String);
+
+impl RustIdent {
+    pub fn new(s: &str) -> RustIdent {
+        assert!(!s.is_empty());
+        assert!(!s.contains("/"), "{}", s);
+        assert!(!s.contains("."), "{}", s);
+        assert!(!s.contains(":"), "{}", s);
+        assert!(!s.contains(" "), "{}", s);
+        assert!(!s.contains("#"), "{}", s);
+        RustIdent(s.to_owned())
+    }
+
+    pub(crate) fn get(&self) -> &str {
+        &self.0
+    }
+
+    pub fn into_string(self) -> String {
+        self.0
+    }
+
+    pub fn to_path(&self) -> RustIdentWithPath {
+        RustIdentWithPath::from(&self.0)
+    }
+
+    pub(crate) fn into_rel_path(self) -> RustRelativePath {
+        RustRelativePath::from_idents([self])
+    }
+}
+
+impl fmt::Display for RustIdent {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        // Rust-protobuf uses `_` suffix to escape identifiers instead of raw identifiers
+        // because some identifiers cannot be escaped as raw identifiers,
+        // e.g. `r#self` is not a valid raw identifier.
+        if is_rust_keyword(&self.0) {
+            write!(f, "{}_", self.0)
+        } else {
+            write!(f, "{}", self.0)
+        }
+    }
+}
+
+impl From<&'_ str> for RustIdent {
+    fn from(s: &str) -> Self {
+        RustIdent::new(s)
+    }
+}
+
+impl From<String> for RustIdent {
+    fn from(s: String) -> Self {
+        RustIdent::new(&s)
+    }
+}