feat(any): make `Grouped` trait unsafe and encapsulate `AnyOutput`

fields

Declare `Grouped` as `unsafe trait` to make its soundness invariant
visible.
Make `AnyOutput.type_id` and `member_id` private; add public accessors
and
the `unsafe fn new_bare` constructor.

5 files changed, 41 insertions, 17 deletions

diff --git a/mingling_macros/src/derive/grouped.rs b/mingling_macros/src/derive/grouped.rs
index 307aab6..a00eea1 100644
--- a/mingling_macros/src/derive/grouped.rs
+++ b/mingling_macros/src/derive/grouped.rs
@@ -16,7 +16,11 @@ pub(crate) fn derive_grouped(input: TokenStream) -> TokenStream {
     let expanded = quote! {
         ::mingling::macros::register_type!(#struct_name);
 
-        impl ::mingling::Grouped<#group_ident> for #struct_name {
+        /// SAFETY: This is an internal implementation of the `Grouped` derive macro,
+        /// guaranteeing that the enum value registered by the `register_type!` macro
+        /// is exactly the same as the actual return value,
+        /// which can be confirmed via the `Ident` in the `quote!` block.
+        unsafe impl ::mingling::Grouped<#group_ident> for #struct_name {
             fn member_id() -> #group_ident {
                 #group_ident::#struct_name
             }
@@ -46,7 +50,11 @@ pub fn derive_grouped_serialize(input: TokenStream) -> TokenStream {
 
         ::mingling::macros::register_type!(#struct_name);
 
-        impl ::mingling::Grouped<#group_ident> for #struct_name {
+        /// SAFETY: This is an internal implementation of the `Grouped` derive macro,
+        /// guaranteeing that the enum value registered by the `register_type!` macro
+        /// is exactly the same as the actual return value,
+        /// which can be confirmed via the `Ident` in the `quote!` block.
+        unsafe impl ::mingling::Grouped<#group_ident> for #struct_name {
             fn member_id() -> #group_ident {
                 #group_ident::#struct_name
             }
diff --git a/mingling_macros/src/func/gen_program.rs b/mingling_macros/src/func/gen_program.rs
index de4da06..db82504 100644
--- a/mingling_macros/src/func/gen_program.rs
+++ b/mingling_macros/src/func/gen_program.rs
@@ -342,7 +342,7 @@ fn main() {
         ) -> Result<::mingling::RenderResult, ::mingling::error::StructuralRendererSerializeError> {
             #[allow(unused_imports)]
             #(#pathf_uses)*
-            match any.member_id {
+            match any.member_id() {
                 #(#structural_renderer_tokens)*
                 _ => {
                     // Non-structural types: render ResultEmpty (which implements
@@ -408,7 +408,7 @@ fn main() {
         fn do_comp(any: &::mingling::AnyOutput<Self::Enum>, ctx: &::mingling::ShellContext) -> ::mingling::Suggest {
             #[allow(unused_imports)]
             #(#pathf_uses)*
-            match any.member_id {
+            match any.member_id() {
                 #(#completion_tokens)*
                 _ => ::mingling::Suggest::FileCompletion,
             }
@@ -442,7 +442,7 @@ fn main() {
         }).collect();
             quote! {
                 fn render(any: ::mingling::AnyOutput<Self::Enum>) -> ::mingling::RenderResult {
-                    match any.member_id {
+                    match any.member_id() {
                         #(#render_arms)*
                         _ => ::mingling::RenderResult::default(),
                     }
@@ -494,9 +494,9 @@ fn main() {
             fn do_chain(
                 any: ::mingling::AnyOutput<Self::Enum>,
             ) -> ::std::pin::Pin<::std::boxed::Box<dyn ::std::future::Future<Output = ::mingling::ChainProcess<Self::Enum>> + ::std::marker::Send>> {
-                match any.member_id {
+                match any.member_id() {
                     #(#chain_arms_async)*
-                    _ => ::core::panic!("No chain found for type id: {:?}", any.type_id),
+                    _ => ::core::panic!("No chain found for type id: {:?}", any.type_id()),
                 }
             }
         }
@@ -505,9 +505,9 @@ fn main() {
             fn do_chain(
                 any: ::mingling::AnyOutput<Self::Enum>,
             ) -> ::mingling::ChainProcess<Self::Enum> {
-                match any.member_id {
+                match any.member_id() {
                     #(#chain_arms_sync)*
-                    _ => ::core::panic!("No chain found for type id: {:?}", any.type_id),
+                    _ => ::core::panic!("No chain found for type id: {:?}", any.type_id()),
                 }
             }
         }
@@ -535,7 +535,7 @@ fn main() {
     let expanded = quote! {
         #pathf_hint
 
-        #[derive(Debug, PartialEq, Eq, Clone)]
+        #[derive(Debug, PartialEq, Eq, Clone, Copy)]
         #[repr(#repr_type)]
         #[allow(nonstandard_style)]
         pub enum #name {
@@ -569,19 +569,19 @@ fn main() {
             fn render_help(any: ::mingling::AnyOutput<Self::Enum>) -> ::mingling::RenderResult {
                 #[allow(unused_imports)]
                 #(#pathf_uses)*
-                match any.member_id {
+                match any.member_id() {
                     #(#help_tokens)*
                     _ => ::mingling::RenderResult::default(),
                 }
             }
             fn has_renderer(any: &::mingling::AnyOutput<Self::Enum>) -> bool {
-                match any.member_id {
+                match any.member_id() {
                     #(#renderer_exist_tokens)*
                     _ => false
                 }
             }
             fn has_chain(any: &::mingling::AnyOutput<Self::Enum>) -> bool {
-                match any.member_id {
+                match any.member_id() {
                     #(#chain_exist_tokens)*
                     _ => false
                 }
diff --git a/mingling_macros/src/func/group.rs b/mingling_macros/src/func/group.rs
index b865913..edb1fe1 100644
--- a/mingling_macros/src/func/group.rs
+++ b/mingling_macros/src/func/group.rs
@@ -133,7 +133,11 @@ pub(crate) fn group_macro(input: TokenStream) -> TokenStream {
             #type_use
             #alias_use
 
-            impl ::mingling::Grouped<__MinglingProgram> for #type_name {
+            /// SAFETY: This is an internal implementation of the `group!` macro,
+            /// guaranteeing that the enum value registered by the `register_type!` macro
+            /// is exactly the same as the actual return value,
+            /// which can be confirmed via the `Ident` in the `quote!` block.
+            unsafe impl ::mingling::Grouped<__MinglingProgram> for #type_name {
                 fn member_id() -> __MinglingProgram {
                     __MinglingProgram::#type_name
                 }
diff --git a/mingling_macros/src/func/pack.rs b/mingling_macros/src/func/pack.rs
index a1a7e6b..7206b8e 100644
--- a/mingling_macros/src/func/pack.rs
+++ b/mingling_macros/src/func/pack.rs
@@ -138,7 +138,11 @@ pub(crate) fn pack(input: TokenStream) -> TokenStream {
             }
         }
 
-        impl ::mingling::Grouped<#group_name> for #type_name {
+        /// SAFETY: This is an internal implementation of the `pack!` macro,
+        /// guaranteeing that the enum value registered by the `register_type!` macro
+        /// is exactly the same as the actual return value,
+        /// which can be confirmed via the `Ident` in the `quote!` block.
+        unsafe impl ::mingling::Grouped<#group_name> for #type_name {
             fn member_id() -> #group_name {
                 #group_name::#type_name
             }
diff --git a/mingling_macros/src/systems/structural_data.rs b/mingling_macros/src/systems/structural_data.rs
index 0a783ec..46d7cf8 100644
--- a/mingling_macros/src/systems/structural_data.rs
+++ b/mingling_macros/src/systems/structural_data.rs
@@ -176,7 +176,11 @@ pub(crate) fn pack_structural(input: TokenStream) -> TokenStream {
             }
         }
 
-        impl ::mingling::Grouped<#program_path> for #type_name {
+        /// SAFETY: This is an internal implementation of the `pack_structural!` macro,
+        /// guaranteeing that the enum value registered by the `register_type!` macro
+        /// is exactly the same as the actual return value,
+        /// which can be confirmed via the `Ident` in the `quote!` block.
+        unsafe impl ::mingling::Grouped<#program_path> for #type_name {
             fn member_id() -> #program_path {
                 #program_path::#type_name
             }
@@ -297,7 +301,11 @@ pub(crate) fn group_structural(input: TokenStream) -> TokenStream {
             #type_use
             #alias_use
 
-            impl ::mingling::Grouped<__MinglingProgram> for #type_name {
+            /// SAFETY: This is an internal implementation of the `pack_structural!` macro,
+            /// guaranteeing that the enum value registered by the `register_type!` macro
+            /// is exactly the same as the actual return value,
+            /// which can be confirmed via the `Ident` in the `quote!` block.
+            unsafe impl ::mingling::Grouped<__MinglingProgram> for #type_name {
                 fn member_id() -> __MinglingProgram {
                     __MinglingProgram::#type_name
                 }