refactor!: replace pack! macros with derive-based pipeline types

Remove the `pack!`, `pack_err!`, `pack_structural!`, and
`pack_err_structural!` macros, replacing all pipeline type definitions
with `#[derive(Grouped)]` and `#[derive(Grouped, Wrap)]` attributes.
This changes the generated struct shape from named-field structs with an
`inner` field to tuple structs accessed via `.0`, and removes the
auto-generated `name` and `info` fields from error types.

1 files changed, 14 insertions, 7 deletions

diff --git a/mingling_cli/src/pkg_mgr.rs b/mingling_cli/src/pkg_mgr.rs
index e140991..8493804 100644
--- a/mingling_cli/src/pkg_mgr.rs
+++ b/mingling_cli/src/pkg_mgr.rs
@@ -8,16 +8,23 @@ pub mod cmd_uninstall;
 use std::path::PathBuf;
 
 use mingling::{
-    Program, RenderResult,
-    macros::{pack_err, program_setup, r_println, renderer},
+    Grouped, Program, RenderResult, Wrap,
+    macros::{program_setup, r_println, renderer},
 };
 
 use crate::{ThisProgram, eprintln_cargo, hprintln_cargo};
 
-pack_err!(ErrorRootPackageNotFound);
-pack_err!(ErrorNoDataDirectory);
-pack_err!(ErrorPackageSpecInvalid = String);
-pack_err!(ErrorPackageNameRequired);
+#[derive(Grouped, Default)]
+pub struct ErrorRootPackageNotFound;
+
+#[derive(Grouped, Default)]
+pub struct ErrorNoDataDirectory;
+
+#[derive(Grouped, Wrap)]
+pub struct ErrorPackageSpecInvalid(String);
+
+#[derive(Grouped, Default)]
+pub struct ErrorPackageNameRequired;
 
 /// The `mingling/packages` packages directory under the user's data directory.
 #[derive(Debug, Default, Clone)]
@@ -55,7 +62,7 @@ pub fn render_error_no_data_directory(_: ErrorNoDataDirectory) -> RenderResult {
 #[renderer]
 pub fn render_error_package_spec_invalid(err: ErrorPackageSpecInvalid) -> RenderResult {
     let mut r = RenderResult::new();
-    eprintln_cargo!(r, "invalid package spec: {}", err.info);
+    eprintln_cargo!(r, "invalid package spec: {}", err.0);
     r
 }