support custom map types (#1011)

Author: JosiahBull

Cargo.lock

@@ -67,6 +67,7 @@ pub struct GenerationSettings {
     post_hook_async: Option<TokenStream>,
     extra_derives: Vec<String>,
 
+    map_type: Option<String>,
     unknown_crates: UnknownPolicy,
     crates: BTreeMap<String, CrateSpec>,
 
@@ -228,6 +229,18 @@ impl GenerationSettings {
         );
         self
     }
+
+    /// Set the type used for key-value maps. Common examples:
+    /// - [`std::collections::HashMap`] - **Default**
+    /// - [`std::collections::BTreeMap`]
+    /// - [`indexmap::IndexMap`]
+    ///
+    /// The requiremnets for a map type can be found in the
+    /// [typify::TypeSpaceSettings::with_map_type] documentation.
+    pub fn with_map_type<MT: ToString>(&mut self, map_type: MT) -> &mut Self {
+        self.map_type = Some(map_type.to_string());
+        self
+    }
 }
 
 impl Default for Generator {
@@ -278,6 +291,11 @@ impl Generator {
                 type_settings.with_conversion(schema.clone(), type_name, impls.iter().cloned());
             });
 
+        // Set the map type if specified.
+        if let Some(map_type) = &settings.map_type {
+            type_settings.with_map_type(map_type.clone());
+        }
+
         Self {
             type_space: TypeSpace::new(&type_settings),
             settings: settings.clone(),

progenitor-impl/src/lib.rs

@@ -139,6 +139,8 @@ struct MacroSettings {
     post_hook: Option<ParseWrapper<ClosureOrPath>>,
     post_hook_async: Option<ParseWrapper<ClosureOrPath>>,
 
+    map_type: Option<ParseWrapper<syn::Type>>,
+
     #[serde(default)]
     derives: Vec<ParseWrapper<syn::Path>>,
 
@@ -305,6 +307,7 @@ fn do_generate_api(item: TokenStream) -> Result<TokenStream, syn::Error> {
             pre_hook_async,
             post_hook,
             post_hook_async,
+            map_type,
             unknown_crates,
             crates,
             derives,
@@ -322,6 +325,7 @@ fn do_generate_api(item: TokenStream) -> Result<TokenStream, syn::Error> {
         post_hook.map(|post_hook| settings.with_post_hook(post_hook.into_inner().0));
         post_hook_async
             .map(|post_hook_async| settings.with_post_hook_async(post_hook_async.into_inner().0));
+        map_type.map(|map_type| settings.with_map_type(map_type.to_token_stream()));
 
         settings.with_unknown_crates(unknown_crates);
         crates.into_iter().for_each(