analysis: use collection types for return when possible

src/analysis/return_value.rs

@@ -122,6 +122,7 @@ pub fn analyze(
         let par = analysis::Parameter::from_return_value(env, lib_par, configured_functions);
         if let Ok(rust_type) = RustType::builder(env, typ)
             .direction(par.lib_par.direction)
+            .c_type(par.lib_par.c_type.clone())
             .try_from_glib(&par.try_from_glib)
             .try_build()
         {
@@ -130,6 +131,7 @@ pub fn analyze(
 
         commented = RustType::builder(env, typ)
             .direction(func.ret.direction)
+            .c_type(par.lib_par.c_type.clone())
             .try_from_glib(&par.try_from_glib)
             .try_build_param()
             .is_err();

src/analysis/rust_type.rs

@@ -191,6 +191,7 @@ pub struct RustTypeBuilder<'env> {
     concurrency: library::Concurrency,
     try_from_glib: TryFromGlib,
     callback_parameters_config: CallbackParameters,
+    c_type: String,
 }
 
 impl<'env> RustTypeBuilder<'env> {
@@ -205,6 +206,7 @@ impl<'env> RustTypeBuilder<'env> {
             concurrency: library::Concurrency::None,
             try_from_glib: TryFromGlib::default(),
             callback_parameters_config: Vec::new(),
+            c_type: String::default(),
         }
     }
 
@@ -238,6 +240,11 @@ impl<'env> RustTypeBuilder<'env> {
         self
     }
 
+    pub fn c_type(mut self, c_type: String) -> Self {
+        self.c_type = c_type;
+        self
+    }
+
     pub fn callback_parameters_config(
         mut self,
         callback_parameters_config: &[CallbackParameter],
@@ -348,7 +355,8 @@ impl<'env> RustTypeBuilder<'env> {
                 if ConversionType::of(self.env, inner_tid) == ConversionType::Pointer =>
             {
                 skip_option = true;
-                let inner_ref_mode = match self.env.type_(inner_tid) {
+                let inner_type = self.env.type_(inner_tid);
+                let inner_ref_mode = match inner_type {
                     Class(..) | Interface(..) => RefMode::None,
                     Record(record) => match RecordType::of(record) {
                         RecordType::Boxed => RefMode::None,
@@ -373,7 +381,59 @@ impl<'env> RustTypeBuilder<'env> {
                             if self.ref_mode.is_ref() {
                                 format!("[{typ}]")
                             } else {
-                                format!("Vec<{typ}>")
+                                let is_obj = matches!(inner_type, Class(_) | Interface(_));
+                                let is_ptr = is_obj
+                                    || matches!(inner_type, Basic(Pointer))
+                                    || (matches!(inner_type, Record(_))
+                                        && self
+                                            .env
+                                            .config
+                                            .objects
+                                            .get(&inner_tid.full_name(&self.env.library))
+                                            .map(|o| !o.boxed_inline)
+                                            .unwrap_or(false));
+                                let is_string = matches!(inner_type, Basic(Utf8));
+                                match *type_ {
+                                    CArray(_) if is_ptr => {
+                                        format!("{}<{typ}>", use_glib_type(self.env, "PtrSlice"))
+                                    }
+                                    CArray(_)
+                                        if is_string
+                                            && matches!(
+                                                self.c_type.as_str(),
+                                                "char**" | "gchar**"
+                                            ) =>
+                                    {
+                                        use_glib_type(self.env, "StrV")
+                                    }
+                                    CArray(_)
+                                        if !matches!(
+                                            inner_type,
+                                            Basic(Utf8 | Filename | OsString | Boolean)
+                                        ) =>
+                                    {
+                                        format!("{}<{typ}>", use_glib_type(self.env, "Slice"))
+                                    }
+                                    List(_) if is_ptr => {
+                                        format!("{}<{typ}>", use_glib_type(self.env, "List"))
+                                    }
+                                    List(_) if is_string => format!(
+                                        "{}<{}>",
+                                        use_glib_type(self.env, "List"),
+                                        use_glib_type(self.env, "GStringPtr")
+                                    ),
+                                    SList(_) if is_ptr => {
+                                        format!("{}<{typ}>", use_glib_type(self.env, "SList"))
+                                    }
+                                    SList(_) if is_string => format!(
+                                        "{}<{}>",
+                                        use_glib_type(self.env, "SList"),
+                                        use_glib_type(self.env, "GStringPtr")
+                                    ),
+                                    /* TODO: Handle Array and PtrArray when they gain type
+                                     * parameters */
+                                    _ => format!("Vec<{typ}>"),
+                                }
                             }
                         })
                     })
@@ -623,6 +683,7 @@ impl<'env> RustTypeBuilder<'env> {
             .direction(self.direction)
             .nullable(self.nullable)
             .ref_mode(self.ref_mode)
+            .c_type(self.c_type)
             .scope(self.scope)
             .try_from_glib(&self.try_from_glib)
             .try_build();

src/codegen/parameter.rs

@@ -29,6 +29,7 @@ impl ToParameter for CParameter {
                     let type_name = RustType::builder(env, self.typ)
                         .direction(self.direction)
                         .nullable(self.nullable)
+                        .c_type(self.c_type.clone())
                         .ref_mode(ref_mode)
                         .scope(self.scope)
                         .try_from_glib(&self.try_from_glib)

src/codegen/return_value.rs

@@ -31,6 +31,7 @@ impl ToReturnValue for library::Parameter {
             .direction(self.direction)
             .nullable(self.nullable)
             .scope(self.scope)
+            .c_type(self.c_type.clone())
             .try_from_glib(try_from_glib)
             .try_build_param()
             .into_string();
@@ -261,6 +262,7 @@ fn out_parameter_as_return(out: &analysis::Parameter, env: &Env) -> String {
     let name = RustType::builder(env, out.lib_par.typ)
         .direction(ParameterDirection::Return)
         .nullable(out.lib_par.nullable)
+        .c_type(out.lib_par.c_type.clone())
         .scope(out.lib_par.scope)
         .try_from_glib(&out.try_from_glib)
         .try_build_param()

src/codegen/translate_from_glib.rs

@@ -88,6 +88,7 @@ impl TranslateFromGlib for analysis::return_value::Info {
                 Some(tid) => {
                     let rust_type = RustType::builder(env, tid)
                         .direction(par.lib_par.direction)
+                        .c_type(par.lib_par.c_type.clone())
                         .try_from_glib(&par.try_from_glib)
                         .try_build();
                     let from_glib_xxx = from_glib_xxx(par.lib_par.transfer, None);