feat(core): decouple structured output from Groupped trait

Introduce `StructuralData` sealed trait and `pack_structural!` /
`group_structural!` / `derive(StructuralData)` macros to control
structured rendering separately from grouping. `Groupped` no longer
requires `Serialize`.

1 files changed, 19 insertions, 0 deletions

diff --git a/mingling/src/lib.rs b/mingling/src/lib.rs
index 70b69bc..4c49f15 100644
--- a/mingling/src/lib.rs
+++ b/mingling/src/lib.rs
@@ -96,15 +96,24 @@ pub mod macros {
     /// Used to register an external type as a group member
     #[cfg(feature = "extra_macros")]
     pub use mingling_macros::group;
+    /// Like `group!` but also marks the type for structured output
+    #[cfg(all(feature = "general_renderer", feature = "extra_macros"))]
+    pub use mingling_macros::group_structural;
     /// Used to generate a struct implementing the `HelpRequest` trait via a method
     pub use mingling_macros::help;
     /// Used to create a `Node` struct via a literal
     pub use mingling_macros::node;
     /// Used to create a wrapper type for use with `Chain` and `Renderer`
     pub use mingling_macros::pack;
+    /// Like `pack!` but also marks the type for structured output
+    #[cfg(feature = "general_renderer")]
+    pub use mingling_macros::pack_structural;
     /// Used to create an error struct with automatic `name` field
     #[cfg(feature = "extra_macros")]
     pub use mingling_macros::pack_err;
+    /// Like `pack_err!` but also marks the type for structured output
+    #[cfg(all(feature = "general_renderer", feature = "extra_macros"))]
+    pub use mingling_macros::pack_err_structural;
     #[cfg(feature = "comp")]
     #[doc(hidden)]
     pub use mingling_macros::program_comp_gen;
@@ -148,6 +157,10 @@ pub use mingling_macros::EnumTag;
 /// derive macro Groupped
 pub use mingling_macros::Groupped;
 
+/// derive macro `StructuralData` — marks a type as supporting structured output
+#[cfg(feature = "general_renderer")]
+pub use mingling_macros::StructuralData;
+
 /// Example projects for `Mingling`, for learning how to use `Mingling`
 pub mod _mingling_examples {
     pub use crate::example_docs::*;
@@ -200,9 +213,15 @@ pub mod prelude {
     pub use crate::macros::gen_program;
     /// Re-export of the `pack` macro for creating wrapper types.
     pub use crate::macros::pack;
+    /// Like `pack!` but also marks the type for structured output
+    #[cfg(feature = "general_renderer")]
+    pub use mingling_macros::pack_structural;
     /// Re-export of the `pack_err` macro for creating error types.
     #[cfg(feature = "extra_macros")]
     pub use crate::macros::pack_err;
+    /// Like `pack_err!` but also marks the type for structured output
+    #[cfg(all(feature = "general_renderer", feature = "extra_macros"))]
+    pub use mingling_macros::pack_err_structural;
     /// Re-export of the `r_print` macro for printing within a renderer context.
     pub use crate::macros::r_print;
     /// Re-export of the `r_println` macro for printing with a newline within a renderer