former : making subforming more friendly

module/core/former/src/axiomatic.rs

@@ -1,5 +1,19 @@
 //! ....
 
+/// xxx2
+pub trait StoragePerform
+{
+  type Formed;
+  fn preform( self ) -> Self::Formed;
+}
+
+/// xxx2
+pub trait FormerDescriptor
+{
+  type Storage : StoragePerform< Formed = Self::Formed >;
+  type Formed;
+}
+
 /// Defines a handler for the end of a subforming process, enabling the return of the original context.
 ///
 /// This trait is designed to be flexible, allowing for various end-of-forming behaviors in builder patterns.
@@ -8,7 +22,7 @@
 /// # Parameters
 /// - `Storage`: The type of the container being processed.
 /// - `Context`: The type of the context that might be altered or returned upon completion.
-pub trait FormingEnd< Storage, Context, Formed >
+pub trait FormingEnd< Former : FormerDescriptor, Context >
 {
   /// Called at the end of the subforming process to return the modified or original context.
   ///
@@ -19,15 +33,15 @@ pub trait FormingEnd< Storage, Context, Formed >
   /// # Returns
   /// Returns the transformed or original context based on the implementation.
   // #[ allow( dead_code ) ]
-  fn call( &self, storage : Storage, context : core::option::Option< Context > ) -> Formed;
+  fn call( &self, storage : Former::Storage, context : core::option::Option< Context > ) -> Former::Formed;
 }
 
-impl< Storage, Context, Formed, F > FormingEnd< Storage, Context, Formed > for F
+impl< Former : FormerDescriptor, Context, F > FormingEnd< Former, Context > for F
 where
-  F : Fn( Storage, core::option::Option< Context > ) -> Formed,
+  F : Fn( Former::Storage, core::option::Option< Context > ) -> Former::Formed,
 {
   #[ inline( always ) ]
-  fn call( &self, storage : Storage, context : core::option::Option< Context > ) -> Formed
+  fn call( &self, storage : Former::Storage, context : core::option::Option< Context > ) -> Former::Formed
   {
     self( storage, context )
   }
@@ -40,13 +54,13 @@ where
 #[ derive( Debug, Default ) ]
 pub struct ReturnStorage;
 
-impl< Storage, Formed > FormingEnd< Storage, (), Formed >
+impl< Former : FormerDescriptor > FormingEnd< Former, () >
 for ReturnStorage
 // where
   // Storage : StoragePreform<>,
 {
   #[ inline( always ) ]
-  fn call( &self, storage : Storage, _context : core::option::Option< () > ) -> Formed
+  fn call( &self, storage : Former::Storage, _context : core::option::Option< () > ) -> Former::Formed
   {
     storage.preform()
   }
@@ -66,14 +80,14 @@ for ReturnStorage
 /// * `Context` - The type of the context that may be altered or returned by the closure.
 ///               This allows for flexible manipulation of context based on the container.
 #[ cfg( not( feature = "no_std" ) ) ]
-pub struct FormingEndWrapper< Storage, Context, Formed >
+pub struct FormingEndWrapper< Former : FormerDescriptor, Context >
 {
-  closure : Box< dyn Fn( Storage, Option< Context > ) -> Formed >,
-  _marker : std::marker::PhantomData< Storage >,
+  closure : Box< dyn Fn( Former::Storage, Option< Context > ) -> Former::Formed >,
+  _marker : std::marker::PhantomData< Former::Storage >,
 }
 
 #[ cfg( not( feature = "no_std" ) ) ]
-impl< Storage, Context, Formed > FormingEndWrapper< Storage, Context, Formed >
+impl< Former : FormerDescriptor, Context > FormingEndWrapper< Former, Context >
 {
   /// Constructs a new `FormingEndWrapper` with the provided closure.
   ///
@@ -86,7 +100,7 @@ impl< Storage, Context, Formed > FormingEndWrapper< Storage, Context, Formed >
   /// # Returns
   ///
   /// Returns an instance of `FormingEndWrapper` encapsulating the provided closure.
-  pub fn new( closure : impl Fn( Storage, Option< Context > ) -> Formed + 'static ) -> Self
+  pub fn new( closure : impl Fn( Former::Storage, Option< Context > ) -> Former::Formed + 'static ) -> Self
   {
     Self
     {
@@ -99,7 +113,7 @@ impl< Storage, Context, Formed > FormingEndWrapper< Storage, Context, Formed >
 #[ cfg( not( feature = "no_std" ) ) ]
 use std::fmt;
 #[ cfg( not( feature = "no_std" ) ) ]
-impl< Storage, Context, Formed > fmt::Debug for FormingEndWrapper< Storage, Context, Formed >
+impl< Former : FormerDescriptor, Context > fmt::Debug for FormingEndWrapper< Former, Context >
 {
   fn fmt( &self, f : &mut fmt::Formatter< '_ > ) -> fmt::Result
   {
@@ -111,10 +125,10 @@ impl< Storage, Context, Formed > fmt::Debug for FormingEndWrapper< Storage, Cont
 }
 
 #[ cfg( not( feature = "no_std" ) ) ]
-impl< Storage, Context, Formed > FormingEnd< Storage, Context, Formed >
-for FormingEndWrapper< Storage, Context, Formed >
+impl< Former : FormerDescriptor, Context > FormingEnd< Former, Context >
+for FormingEndWrapper< Former, Context >
 {
-  fn call( &self, storage : Storage, context : Option< Context > ) -> Formed
+  fn call( &self, storage : Former::Storage, context : Option< Context > ) -> Former::Formed
   {
     ( self.closure )( storage, context )
   }

module/core/former/src/vector.rs

@@ -22,6 +22,28 @@ impl< E > VectorLike< E > for Vec< E >
   }
 }
 
+impl< E > StoragePerform for VectorLike< E >
+where
+  Self : Sized,
+{
+  type Formed = Self;
+  fn preform( self ) -> Self::Formed
+  {
+    self
+  }
+}
+
+impl< E, Former, Formed, Context, End,  > FormerDescriptor
+for VectorSubformer< Former, Context, End >
+where
+  Formed : StoragePerform< Formed = Formed > + VectorLike< E > + core::default::Default,
+  End : FormingEnd< Self, Context >,
+  Former : FormerDescriptor,
+{
+  type Storage = Formed;
+  type Formed = Formed;
+}
+
 /// A builder for constructing `VectorLike` containers, facilitating a fluent and flexible interface.
 ///
 /// `VectorSubformer` leverages the `VectorLike` trait to enable the construction and manipulation
@@ -48,26 +70,30 @@ impl< E > VectorLike< E > for Vec< E >
 ///
 // xxx2 : change sequence of parameters
 #[ derive( Debug, Default ) ]
-pub struct VectorSubformer< E, Formed, Context, ContainerEnd >
+// pub struct VectorSubformer< E, Formed, Context, End >
+pub struct VectorSubformer< Former, Context, End >
 where
-  Formed : VectorLike< E > + core::default::Default,
-  ContainerEnd : FormingEnd< Formed, Context, Formed >,
+  // Formed : StoragePerform< Formed = Formed > + VectorLike< E > + core::default::Default,
+  Former : FormerDescriptor,
+  End : FormingEnd< Self, Context >,
 {
-  formed : core::option::Option< Formed >,
+  formed : core::option::Option< Former::Formed >,
   context : core::option::Option< Context >,
-  on_end : core::option::Option< ContainerEnd >,
-  _phantom : core::marker::PhantomData< E >,
+  on_end : core::option::Option< End >,
+  // _phantom : core::marker::PhantomData< E >,
 }
 
-impl< E, Formed, Context, ContainerEnd > VectorSubformer< E, Formed, Context, ContainerEnd >
+impl< Former, Context, End > VectorSubformer< Former, Context, End >
 where
-  Formed : VectorLike< E > + core::default::Default,
-  ContainerEnd : FormingEnd< Formed, Context, Formed >,
+  Former : FormerDescriptor,
+  End : FormingEnd< Self, Context >,
+  // Formed : VectorLike< E > + core::default::Default,
+  // End : FormingEnd< Self, Context >,
 {
 
   /// Form current former into target structure.
   #[ inline( always ) ]
-  pub fn form( mut self ) -> Formed
+  pub fn form( mut self ) -> Former::Formed
   {
     let formed = if self.formed.is_some()
     {
@@ -85,9 +111,9 @@ where
   #[ inline( always ) ]
   pub fn begin
   (
-    formed : core::option::Option< Formed >,
+    formed : core::option::Option< Former::Formed >,
     context : core::option::Option< Context >,
-    on_end : ContainerEnd
+    on_end : End
   ) -> Self
   {
     Self
@@ -101,7 +127,7 @@ where
 
   /// Finalizes the building process, returning the formed or a context incorporating it.
   #[ inline( always ) ]
-  pub fn end( mut self ) -> Formed
+  pub fn end( mut self ) -> Former::Formed
   {
     let on_end = self.on_end.take().unwrap();
     let context = self.context.take();
@@ -111,7 +137,7 @@ where
 
   /// Replaces the current formed with a provided one, allowing for a reset or redirection of the building process.
   #[ inline( always ) ]
-  pub fn replace( mut self, vector : Formed ) -> Self
+  pub fn replace( mut self, vector : Former::Formed ) -> Self
   {
     self.formed = Some( vector );
     self
@@ -143,10 +169,10 @@ where
 
 }
 
-impl< E, Formed, Context, ContainerEnd > VectorSubformer< E, Formed, Context, ContainerEnd >
+impl< E, Formed, Context, End > VectorSubformer< E, Formed, Context, End >
 where
   Formed : VectorLike< E > + core::default::Default,
-  ContainerEnd : FormingEnd< Formed, Context, Formed >,
+  End : FormingEnd< Self, Context >,
 {
 
   /// Appends an element to the end of the formed, expanding the internal collection.
@@ -172,7 +198,7 @@ where
 impl< E, Formed, Context, End > FormerBegin< Formed, Formed, Context >
 for VectorSubformer< E, Formed, Context, End >
 where
-  End : FormingEnd< Formed, Context, Formed >,
+  End : FormingEnd< Self, Context >,
   Formed : VectorLike< E > + Default,
 {
   type End = End;