Make darling_core::{codegen, options} crate-private

This will make internal refactoring easier going forward.

This change also removes dead code exposed by making the crates private.

Fixes #58

core/src/codegen/trait_impl.rs

@@ -27,16 +27,13 @@ impl<'a> TraitImpl<'a> {
             .collect()
     }
 
-    /// Get the type parameters which are used by non-skipped fields.
+    /// Get the type parameters which are used by non-skipped, non-magic fields.
+    /// These type parameters will have a `FromMeta` bound applied to them in emitted
+    /// code.
     pub fn used_type_params(&self) -> IdentSet {
         self.type_params_matching(|f| !f.skip, |v| !v.skip)
     }
 
-    /// Get the type parameters which are used by skipped fields.
-    pub fn skipped_type_params(&self) -> IdentSet {
-        self.type_params_matching(|f| f.skip, |v| v.skip)
-    }
-
     fn type_params_matching<'b, F, V>(&'b self, field_filter: F, variant_filter: V) -> IdentSet
     where
         F: Fn(&&Field) -> bool,

core/src/lib.rs

@@ -19,7 +19,7 @@ mod macros_private;
 mod macros_public;
 
 pub mod ast;
-pub mod codegen;
+pub(crate) mod codegen;
 pub mod derive;
 pub mod error;
 mod from_derive_input;
@@ -29,7 +29,7 @@ mod from_generics;
 mod from_meta;
 mod from_type_param;
 mod from_variant;
-pub mod options;
+pub(crate) mod options;
 pub mod usage;
 pub mod util;
 

core/src/options/shape.rs

@@ -26,15 +26,6 @@ pub struct Shape {
     any: bool,
 }
 
-impl Shape {
-    pub fn all() -> Self {
-        Shape {
-            any: true,
-            ..Default::default()
-        }
-    }
-}
-
 impl Default for Shape {
     fn default() -> Self {
         Shape {