Some docs

serde_derive/src/internals/case.rs

@@ -6,6 +6,9 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
+//! Stuff to handle where the case of the source (e.g. `my-field`) is different to the
+//! field/variant (e.g. `my_field`).
+
 // See https://users.rust-lang.org/t/psa-dealing-with-warning-unused-import-std-ascii-asciiext-in-today-s-nightly/13726
 #[allow(deprecated, unused_imports)]
 use std::ascii::AsciiExt;
@@ -14,6 +17,7 @@ use std::str::FromStr;
 
 use self::RenameRule::*;
 
+/// The different possible ways to change case of fields in a struct, or variants in an enum.
 #[derive(PartialEq)]
 pub enum RenameRule {
     /// Don't apply a default rename rule.
@@ -40,6 +44,7 @@ pub enum RenameRule {
 }
 
 impl RenameRule {
+    /// Apply a renaming rule to an enum variant, returning the version expected in the source.
     pub fn apply_to_variant(&self, variant: &str) -> String {
         match *self {
             None | PascalCase => variant.to_owned(),
@@ -64,6 +69,7 @@ impl RenameRule {
         }
     }
 
+    /// Apply a renaming rule to a struct field, returning the version expected in the source.
     pub fn apply_to_field(&self, field: &str) -> String {
         match *self {
             None | LowerCase | SnakeCase => field.to_owned(),