xml: some refactoring

crates/xml/derive/src/de/de_enum.rs

@@ -1,9 +1,69 @@
 use crate::de::attrs::VariantAttrs;
-use darling::FromVariant;
+use darling::{FromDeriveInput, FromVariant};
 use heck::ToKebabCase;
 use quote::quote;
 use syn::{DataEnum, DeriveInput, Fields, FieldsUnnamed, Variant};
 
+use super::attrs::EnumAttrs;
+
+pub struct Enum {
+    attrs: EnumAttrs,
+    variants: Vec<syn::Variant>,
+    ident: syn::Ident,
+    generics: syn::Generics,
+}
+
+impl Enum {
+    pub fn impl_de(&self) -> proc_macro2::TokenStream {
+        let (impl_generics, type_generics, where_clause) = self.generics.split_for_impl();
+        let name = &self.ident;
+
+        let variants = self.variants.iter().map(|variant| {
+            let attrs = VariantAttrs::from_variant(variant).unwrap();
+            let variant_name = attrs.common.rename.unwrap_or(syn::LitByteStr::new(
+                variant.ident.to_string().to_kebab_case().as_bytes(),
+                variant.ident.span(),
+            ));
+            let branch = enum_variant_branch(variant);
+
+            quote! { #variant_name => { #branch } }
+        });
+
+        quote! {
+            impl #impl_generics ::rustical_xml::XmlDeserialize for #name #type_generics #where_clause {
+                fn deserialize<R: std::io::BufRead>(
+                    reader: &mut quick_xml::NsReader<R>,
+                    start: &quick_xml::events::BytesStart,
+                    empty: bool
+                ) -> Result<Self, rustical_xml::XmlDeError> {
+                    use quick_xml::events::Event;
+
+                    let (_ns, name) = reader.resolve_element(start.name());
+
+                    match name.as_ref() {
+                        #(#variants),*
+                        name => {
+                            // Handle invalid variant name
+                            Err(rustical_xml::XmlDeError::InvalidVariant(String::from_utf8_lossy(name).to_string()))
+                        }
+                    }
+                }
+            }
+        }
+    }
+
+    pub fn parse(input: &DeriveInput, data: &DataEnum) -> Self {
+        let attrs = EnumAttrs::from_derive_input(input).unwrap();
+
+        Self {
+            attrs,
+            variants: data.variants.iter().cloned().collect(),
+            ident: input.ident.to_owned(),
+            generics: input.generics.to_owned(),
+        }
+    }
+}
+
 pub fn enum_variant_branch(variant: &Variant) -> proc_macro2::TokenStream {
     let ident = &variant.ident;
 
@@ -30,46 +90,3 @@ pub fn enum_variant_branch(variant: &Variant) -> proc_macro2::TokenStream {
         }
     }
 }
-
-pub fn impl_de_enum(input: &DeriveInput, data: &DataEnum) -> proc_macro2::TokenStream {
-    let (impl_generics, type_generics, where_clause) = input.generics.split_for_impl();
-    let name = &input.ident;
-
-    let variants = data.variants.iter().map(|variant| {
-        let attrs = VariantAttrs::from_variant(variant).unwrap();
-        let variant_name = attrs.common.rename.unwrap_or(syn::LitByteStr::new(
-            variant.ident.to_string().to_kebab_case().as_bytes(),
-            variant.ident.span(),
-        ));
-        let branch = enum_variant_branch(variant);
-        dbg!(&variant_name);
-
-        quote! {
-            #variant_name => {
-                #branch
-            }
-        }
-    });
-
-    quote! {
-        impl #impl_generics ::rustical_xml::XmlDeserialize for #name #type_generics #where_clause {
-            fn deserialize<R: std::io::BufRead>(
-                reader: &mut quick_xml::NsReader<R>,
-                start: &quick_xml::events::BytesStart,
-                empty: bool
-            ) -> Result<Self, rustical_xml::XmlDeError> {
-                use quick_xml::events::Event;
-
-                let (_ns, name) = reader.resolve_element(start.name());
-
-                match name.as_ref() {
-                    #(#variants)*
-                    name => {
-                        // Handle invalid variant name
-                        Err(rustical_xml::XmlDeError::InvalidVariant(String::from_utf8_lossy(name).to_string()))
-                    }
-                }
-            }
-        }
-    }
-}

crates/xml/derive/src/de/de_struct.rs

@@ -94,17 +94,17 @@ impl NamedStruct {
 
                     // initialise fields
                     struct StructBuilder #type_generics #where_clause {
-                        #(#builder_fields)*
+                        #(#builder_fields),*
                     }
 
                     let mut builder = StructBuilder {
-                        #(#builder_field_inits)*
+                        #(#builder_field_inits),*
                     };
 
                     for attr in start.attributes() {
                         let attr = attr?;
                         match attr.key.as_ref() {
-                            #(#attr_field_branches)*
+                            #(#attr_field_branches),*
                             _ => { #invalid_field_branch }
                         }
                     }
@@ -122,8 +122,8 @@ impl NamedStruct {
                                     let empty = matches!(event, Event::Empty(_));
                                     let (ns, name) = reader.resolve_element(start.name());
                                     match (ns, name.as_ref()) {
-                                        #(#named_field_branches)*
+                                        #(#named_field_branches),*
-                                        #(#untagged_field_branches)*
+                                        #(#untagged_field_branches),*
                                         _ => { #invalid_field_branch }
                                     }
                                 }
@@ -156,7 +156,7 @@ impl NamedStruct {
                     }
 
                     Ok(Self {
-                        #(#builder_field_builds)*
+                        #(#builder_field_builds),*
                     })
                 }
             }

crates/xml/derive/src/de/field.rs

@@ -1,3 +1,5 @@
+use crate::de::field;
+
 use super::attrs::{ContainerAttrs, FieldAttrs, FieldType};
 use darling::FromField;
 use heck::ToKebabCase;
@@ -45,7 +47,9 @@ impl Field {
             container_attrs,
         }
     }
-    pub fn de_name(&self) -> syn::LitByteStr {
+
+    /// Field name in XML
+    pub fn xml_name(&self) -> syn::LitByteStr {
         self.attrs
             .common
             .rename
@@ -56,10 +60,12 @@ impl Field {
             ))
     }
 
+    /// Whether to enforce the correct XML namespace
     pub fn ns_strict(&self) -> bool {
         self.attrs.common.ns_strict.is_present() || self.container_attrs.ns_strict.is_present()
     }
 
+    /// Field identifier
     pub fn field_ident(&self) -> &syn::Ident {
         self.field
             .ident
@@ -67,48 +73,52 @@ impl Field {
             .expect("tuple structs not supported")
     }
 
+    /// Field type
     pub fn ty(&self) -> &syn::Type {
         &self.field.ty
     }
 
+    /// Field in the builder struct for the deserializer
     pub fn builder_field(&self) -> proc_macro2::TokenStream {
         let field_ident = self.field_ident();
         let ty = self.ty();
-        match (self.attrs.flatten.is_present(), &self.attrs.default) {
+
-            (_, Some(_default)) => quote! { #field_ident: #ty, },
+        let builder_field_type = match (self.attrs.flatten.is_present(), &self.attrs.default) {
+            (_, Some(_default)) => quote! { #ty },
             (true, None) => {
                 let generic_type = get_generic_type(ty).expect("flatten attribute only implemented for explicit generics (rustical_xml will assume the first generic as the inner type)");
-                quote! { #field_ident: Vec<#generic_type>, }
+                quote! { Vec<#generic_type> }
-            }
-            (false, None) => quote! { #field_ident: Option<#ty>, },
             }
+            (false, None) => quote! { Option<#ty> },
+        };
+
+        quote! { #field_ident: #builder_field_type }
     }
 
+    /// Field initialiser in the builder struct for the deserializer
     pub fn builder_field_init(&self) -> proc_macro2::TokenStream {
         let field_ident = self.field_ident();
-        match (self.attrs.flatten.is_present(), &self.attrs.default) {
+        let builder_field_initialiser = match (self.attrs.flatten.is_present(), &self.attrs.default)
-            (_, Some(default)) => quote! { #field_ident: #default(), },
+        {
-            (true, None) => quote! { #field_ident: vec![], },
+            (_, Some(default)) => quote! { #default() },
-            (false, None) => quote! { #field_ident: None, },
+            (true, None) => quote! { vec![] },
-        }
+            (false, None) => quote! { None },
+        };
+        quote! { #field_ident: #builder_field_initialiser }
     }
 
+    /// Map builder field to target field
     pub fn builder_field_build(&self) -> proc_macro2::TokenStream {
         let field_ident = self.field_ident();
-        match (
+        let builder_value = match (
             self.attrs.flatten.is_present(),
             self.attrs.default.is_some(),
         ) {
-            (true, _) => quote! {
+            (true, _) => quote! { FromIterator::from_iter(builder.#field_ident.into_iter()) },
-                #field_ident: FromIterator::from_iter(builder.#field_ident.into_iter())
+            (false, true) => quote! { builder.#field_ident },
-            },
+            (false, false) => quote! { builder.#field_ident.expect("todo: handle missing field") },
-            (false, true) => quote! {
+        };
-                #field_ident: builder.#field_ident,
+        quote! { #field_ident: #builder_value }
-            },
-            (false, false) => quote! {
-                #field_ident: builder.#field_ident.expect("todo: handle missing field"),
-            },
-        }
     }
 
     pub fn named_branch(&self) -> Option<proc_macro2::TokenStream> {
@@ -126,7 +136,7 @@ impl Field {
             quote! {_}
         };
 
-        let field_name = self.de_name();
+        let field_name = self.xml_name();
         let field_ident = self.field_ident();
         let deserializer = self.ty();
         let value = quote! { <#deserializer as rustical_xml::XmlDeserialize>::deserialize(reader, &start, empty)? };
@@ -147,7 +157,7 @@ impl Field {
         };
 
         Some(quote! {
-            (#namespace_match, #field_name) => { #assignment; },
+            (#namespace_match, #field_name) => { #assignment; }
         })
     }
 
@@ -163,13 +173,13 @@ impl Field {
             quote! {
                 _ => {
                      builder.#field_ident.push(<#deserializer as rustical_xml::XmlDeserialize>::deserialize(reader, &start, empty)?);
-                },
+                }
             }
         } else {
             quote! {
                 _ => {
                      builder.#field_ident = Some(<#deserializer as rustical_xml::XmlDeserialize>::deserialize(reader, &start, empty)?);
-                },
+                }
             }
         })
     }
@@ -195,7 +205,7 @@ impl Field {
             return None;
         }
         let field_ident = self.field_ident();
-        let field_name = self.de_name();
+        let field_name = self.xml_name();
 
         let value = wrap_option_if_no_default(
             quote! {

crates/xml/derive/src/de/mod.rs

@@ -3,6 +3,6 @@ mod de_enum;
 mod de_struct;
 mod field;
 
-pub use de_enum::impl_de_enum;
+pub use de_enum::Enum;
 pub use de_struct::NamedStruct;
 pub use field::Field;

crates/xml/derive/src/lib.rs

@@ -2,14 +2,14 @@ use core::panic;
 use syn::{parse_macro_input, DeriveInput};
 
 mod de;
-use de::{impl_de_enum, NamedStruct};
+use de::{Enum, NamedStruct};
 
 #[proc_macro_derive(XmlDeserialize, attributes(xml))]
 pub fn derive_xml_deserialize(input: proc_macro::TokenStream) -> proc_macro::TokenStream {
     let input = parse_macro_input!(input as DeriveInput);
 
     match &input.data {
-        syn::Data::Enum(e) => impl_de_enum(&input, e),
+        syn::Data::Enum(e) => Enum::parse(&input, e).impl_de(),
         syn::Data::Struct(s) => NamedStruct::parse(&input, s).impl_de(),
         syn::Data::Union(_) => panic!("Union not supported"),
     }