iana: manually implement JsonSchema/Display/FromStr/Serialize/Deserialize

This removes the dependency on serde_with and parse-display, and makes
the serde & schemars dependencies optional

crates/iana-codegen/src/main.rs

@@ -1,4 +1,4 @@
-// Copyright 2022 The Matrix.org Foundation C.I.C.
+// Copyright 2022, 2023 The Matrix.org Foundation C.I.C.
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
@@ -23,6 +23,7 @@ use reqwest::Client;
 use tokio::io::AsyncWriteExt;
 use tracing::Level;
 
+mod gen;
 pub mod jose;
 pub mod oauth;
 pub mod traits;
@@ -82,10 +83,11 @@ impl File {
 }
 
 impl Display for File {
+    #[allow(clippy::too_many_lines)]
     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         writeln!(
             f,
-            r#"// Copyright 2022 The Matrix.org Foundation C.I.C.
+            r#"// Copyright 2023 The Matrix.org Foundation C.I.C.
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
@@ -102,11 +104,7 @@ impl Display for File {
 //! Enums from the {:?} IANA registry
 //! See <{}>
 
-// Do not edit this file manually
-
-use parse_display::{{Display, FromStr}};
-use schemars::JsonSchema;
-use serde_with::{{DeserializeFromStr, SerializeDisplay}};"#,
+// Do not edit this file manually"#,
             self.registry_name, self.registry_url,
         )?;
 
@@ -116,61 +114,25 @@ use serde_with::{{DeserializeFromStr, SerializeDisplay}};"#,
             };
 
             let is_exhaustive = section.key == "OAuthAuthorizationEndpointResponseType";
+            writeln!(f)?;
 
-            let non_exhaustive_attr = if is_exhaustive {
-                ""
-            } else {
-                "\n#[non_exhaustive]"
-            };
+            self::gen::struct_def(f, section, list, is_exhaustive)?;
+            writeln!(f)?;
 
-            write!(
-                f,
-                r#"
-/// {}
-///
-/// Source: <{}>
-#[derive(
-    Debug,
-    Clone,
-    PartialEq,
-    Eq,
-    PartialOrd,
-    Ord,
-    Hash,
-    Display,
-    FromStr,
-    SerializeDisplay,
-    DeserializeFromStr,
-    JsonSchema,
-)]{}
-pub enum {} {{"#,
-                section.doc,
-                section.url.unwrap(),
-                non_exhaustive_attr,
-                section.key,
-            )?;
-            for member in list {
-                writeln!(f)?;
-                if let Some(description) = &member.description {
-                    writeln!(f, "    /// {description}")?;
-                } else {
-                    writeln!(f, "    /// `{}`", member.value)?;
-                }
-                writeln!(f, "    #[schemars(rename = \"{}\")]", member.value)?;
-                writeln!(f, "    #[display(\"{}\")]", member.value)?;
-                writeln!(f, "    {},", member.enum_name)?;
-            }
+            // Write the Display impl
+            self::gen::display_impl(f, section, list, is_exhaustive)?;
+            writeln!(f)?;
 
-            if !is_exhaustive {
-                // Add a variant for custom enums
-                writeln!(f)?;
-                writeln!(f, "    /// An unknown value.")?;
-                writeln!(f, "    #[display(\"{{0}}\")]")?;
-                writeln!(f, "    #[schemars(skip)]")?;
-                writeln!(f, "    Unknown(String),")?;
-            }
+            // Write the FromStr impl
+            self::gen::from_str_impl(f, section, list, is_exhaustive)?;
+            writeln!(f)?;
 
-            writeln!(f, "}}")?;
+            // Write the Serialize and Deserialize impls
+            self::gen::serde_impl(f, section)?;
+            writeln!(f)?;
+
+            // Write the JsonSchema impl
+            self::gen::json_schema_impl(f, section, list)?;
         }
 
         Ok(())