Simple deserializer (#7)

instant-xml-macros/src/de.rs

@@ -0,0 +1,254 @@
+use proc_macro2::{Ident, Span, TokenStream};
+use quote::quote;
+
+use crate::{get_namespaces, retrieve_attr};
+
+struct Tokens {
+    enum_: TokenStream,
+    consts: TokenStream,
+    names: TokenStream,
+    match_: TokenStream,
+}
+
+impl Default for Tokens {
+    fn default() -> Self {
+        Self {
+            enum_: TokenStream::new(),
+            consts: TokenStream::new(),
+            names: TokenStream::new(),
+            match_: TokenStream::new(),
+        }
+    }
+}
+
+pub struct Deserializer {
+    out: TokenStream,
+}
+
+impl quote::ToTokens for Deserializer {
+    fn to_tokens(&self, tokens: &mut TokenStream) {
+        tokens.extend(self.out.clone());
+    }
+}
+
+impl Deserializer {
+    pub fn new(input: &syn::DeriveInput) -> Deserializer {
+        let ident = &input.ident;
+        let name = ident.to_string();
+        let mut out = TokenStream::new();
+
+        let (_, other_namespaces) = get_namespaces(&input.attrs);
+        let mut namespaces_map = quote!(let mut namespaces_map = std::collections::HashMap::new(););
+        for (k, v) in other_namespaces.iter() {
+            namespaces_map.extend(quote!(
+                namespaces_map.insert(#k, #v);
+            ))
+        }
+
+        // Varying values
+        let mut elements_tokens = Tokens::default();
+        let mut attributes_tokens = Tokens::default();
+
+        // Common values
+        let mut declare_values = TokenStream::new();
+        let mut return_val = TokenStream::new();
+
+        match &input.data {
+            syn::Data::Struct(ref data) => {
+                match data.fields {
+                    syn::Fields::Named(ref fields) => {
+                        fields.named.iter().enumerate().for_each(|(index, field)| {
+                            let is_element;
+                            let tokens = match retrieve_attr("attribute", &field.attrs) {
+                                Some(true) => {
+                                    is_element = false;
+                                    &mut attributes_tokens
+                                }
+                                _ => {
+                                    is_element = true;
+                                    &mut elements_tokens
+                                }
+                            };
+
+                            Self::process_field(
+                                field,
+                                index,
+                                &mut declare_values,
+                                &mut return_val,
+                                tokens,
+                                is_element,
+                            );
+                        });
+                    }
+                    syn::Fields::Unnamed(_) => todo!(),
+                    syn::Fields::Unit => {}
+                };
+            }
+            _ => todo!(),
+        };
+
+        // Elements
+        let elements_enum = elements_tokens.enum_;
+        let elements_consts = elements_tokens.consts;
+        let elements_names = elements_tokens.names;
+        let elem_type_match = elements_tokens.match_;
+
+        // Attributes
+        let attributes_enum = attributes_tokens.enum_;
+        let attributes_consts = attributes_tokens.consts;
+        let attributes_names = attributes_tokens.names;
+        let attr_type_match = attributes_tokens.match_;
+
+        out.extend(quote!(
+            fn deserialize(deserializer: &mut ::instant_xml::Deserializer) -> Result<Self, ::instant_xml::Error> {
+                use ::instant_xml::parse::XmlRecord;
+                use ::instant_xml::{Error, Deserializer, Visitor} ;
+
+                enum __Elements {
+                    #elements_enum
+                    __Ignore,
+                }
+
+                fn get_element(value: &str) -> __Elements {
+                    #elements_consts
+                    match value {
+                        #elements_names
+                        _ => __Elements::__Ignore
+                    }
+                }
+
+                enum __Attributes {
+                    #attributes_enum
+                    __Ignore,
+                }
+
+                fn get_attribute(value: &str) -> __Attributes {
+                    #attributes_consts
+                    match value {
+                        #attributes_names
+                        _ => __Attributes::__Ignore
+                    }
+                }
+
+                struct StructVisitor;
+                impl<'xml> Visitor<'xml> for StructVisitor {
+                    type Value = #ident;
+
+                    fn visit_struct<'a>(&self, deserializer: &mut ::instant_xml::Deserializer) -> Result<Self::Value, ::instant_xml::Error>
+                    {
+                        #declare_values
+
+                        while let Some(( key, _ )) = deserializer.peek_next_attribute() {
+                            match get_attribute(&key) {
+                                #attr_type_match
+                                __Attributes::__Ignore => todo!(),
+                            }
+                        }
+                        while let Some(item) = &deserializer.peek_next_tag()? {
+                            match item {
+                                XmlRecord::Open(item) => {
+                                    match get_element(&item.key.as_ref()) {
+                                        #elem_type_match
+                                        __Elements::__Ignore => todo!(),
+                                    }
+                                 }
+                                 XmlRecord::Close(tag) => {
+                                    if tag == &#name {
+                                        break;
+                                    }
+                                },
+                                XmlRecord::Element(_) => panic!("Unexpected element"),
+                            }
+                        }
+
+                        Ok(Self::Value {
+                            #return_val
+                    })
+                    }
+                }
+
+                #namespaces_map;
+                deserializer.deserialize_struct(StructVisitor{}, #name, &namespaces_map)
+            }
+        ));
+
+        out.extend(quote!(
+            const TAG_NAME: ::instant_xml::TagName<'xml> = ::instant_xml::TagName::Custom(#name);
+        ));
+
+        Deserializer { out }
+    }
+
+    fn process_field(
+        field: &syn::Field,
+        index: usize,
+        declare_values: &mut TokenStream,
+        return_val: &mut TokenStream,
+        tokens: &mut Tokens,
+        is_element: bool,
+    ) {
+        let field_var = field.ident.as_ref().unwrap();
+        let field_var_str = field_var.to_string();
+        let const_field_var_str = Ident::new(&field_var_str.to_uppercase(), Span::call_site());
+        let field_type = match &field.ty {
+            syn::Type::Path(v) => v.path.get_ident(),
+            _ => todo!(),
+        };
+
+        let enum_name = Ident::new(&format!("__Value{index}"), Span::call_site());
+        tokens.enum_.extend(quote!(#enum_name,));
+
+        tokens.consts.extend(quote!(
+            const #const_field_var_str: &str = match #field_type::TAG_NAME {
+                ::instant_xml::TagName::FieldName => #field_var_str,
+                ::instant_xml::TagName::Custom(v) => v,
+            };
+        ));
+
+        if is_element {
+            tokens.names.extend(quote!(
+                #const_field_var_str => __Elements::#enum_name,
+            ));
+        } else {
+            tokens.names.extend(quote!(
+                #const_field_var_str => __Attributes::#enum_name,
+            ));
+        }
+
+        declare_values.extend(quote!(
+            let mut #enum_name: Option<#field_type> = None;
+        ));
+
+        if is_element {
+            tokens.match_.extend(quote!(
+                __Elements::#enum_name => {
+                    if #enum_name.is_some() {
+                        panic!("duplicated value");
+                    }
+
+                    if let Some(item) = item.prefix {
+                        let prefix = item.to_owned();
+                        deserializer.verify_namespace(&prefix);
+                    }
+
+                    #enum_name = Some(#field_type::deserialize(deserializer)?);
+                },
+            ));
+        } else {
+            tokens.match_.extend(quote!(
+                __Attributes::#enum_name => {
+                    if #enum_name.is_some() {
+                        panic!("duplicated value");
+                    }
+
+                    deserializer.set_next_type_as_attribute()?;
+                    #enum_name = Some(#field_type::deserialize(deserializer)?);
+                },
+            ));
+        }
+
+        return_val.extend(quote!(
+            #field_var: #enum_name.expect("Expected some value"),
+        ));
+    }
+}

instant-xml-macros/src/lib.rs

@@ -1,5 +1,6 @@
 extern crate proc_macro;
 
+mod de;
 mod se;
 
 use std::collections::{BTreeSet, HashMap};
@@ -12,7 +13,7 @@ use crate::se::Serializer;
 
 const XML: &str = "xml";
 
-enum FieldAttribute {
+pub(crate) enum FieldAttribute {
     Namespace(String),
     PrefixIdentifier(String),
 }
@@ -66,6 +67,30 @@ pub(crate) fn retrieve_field_attribute(name: &str, input: &syn::Field) -> Option
     None
 }
 
+pub(crate) fn retrieve_attr(name: &str, attributes: &Vec<syn::Attribute>) -> Option<bool> {
+    for attr in attributes {
+        if !attr.path.is_ident(XML) {
+            continue;
+        }
+
+        let nested = match attr.parse_meta() {
+            Ok(Meta::List(meta)) => meta.nested,
+            _ => return Some(false),
+        };
+
+        let path = match nested.first() {
+            Some(NestedMeta::Meta(Meta::Path(path))) => path,
+            _ => return Some(false),
+        };
+
+        if path.get_ident()? == name {
+            return Some(true);
+        }
+    }
+
+    None
+}
+
 fn retrieve_attr_list(name: &str, attributes: &Vec<syn::Attribute>) -> Option<syn::MetaList> {
     for attr in attributes {
         if !attr.path.is_ident(XML) {
@@ -74,8 +99,7 @@ fn retrieve_attr_list(name: &str, attributes: &Vec<syn::Attribute>) -> Option<sy
 
         let nested = match attr.parse_meta() {
             Ok(Meta::List(meta)) => meta.nested,
-            Ok(_) => todo!(),
-            _ => todo!(),
+            _ => return None,
         };
 
         let list = match nested.first() {
@@ -134,7 +158,7 @@ pub fn to_xml(input: proc_macro::TokenStream) -> proc_macro::TokenStream {
                 // Check if prefix exist
                 #(
                     if serializer.parent_prefixes.get(#missing_prefixes).is_none() {
-                        return Err(instant_xml::Error::WrongPrefix);
+                        return Err(instant_xml::Error::UnexpectedPrefix);
                     }
                 )*;
 
@@ -159,18 +183,13 @@ pub fn to_xml(input: proc_macro::TokenStream) -> proc_macro::TokenStream {
 
 #[proc_macro_derive(FromXml, attributes(xml))]
 pub fn from_xml(input: proc_macro::TokenStream) -> proc_macro::TokenStream {
-    let ast = parse_macro_input!(input as syn::ItemStruct);
+    let ast = parse_macro_input!(input as syn::DeriveInput);
     let ident = &ast.ident;
-    let name = ident.to_string();
+
+    let deserializer = de::Deserializer::new(&ast);
     proc_macro::TokenStream::from(quote!(
         impl<'xml> FromXml<'xml> for #ident {
-            fn from_xml(input: &str) -> Result<Self, ::instant_xml::Error> {
-                use ::instant_xml::parse::Parse;
-                let mut iter = ::instant_xml::xmlparser::Tokenizer::from(input);
-                iter.next().element_start(None, #name)?;
-                iter.next().element_end(None, #name)?;
-                Ok(Self)
-            }
+            #deserializer
         }
     ))
 }

instant-xml/src/impls.rs

@@ -0,0 +1,27 @@
+use std::str::FromStr;
+
+use crate::{Deserializer, EntityType, Error, FromXml, TagName, Visitor};
+
+struct BoolVisitor;
+
+impl<'de> Visitor<'de> for BoolVisitor {
+    type Value = bool;
+
+    fn visit_str<'a>(self, value: &str) -> Result<Self::Value, Error> {
+        match FromStr::from_str(value) {
+            Ok(v) => Ok(v),
+            Err(e) => Err(Error::Other(e.to_string())),
+        }
+    }
+}
+
+impl<'xml> FromXml<'xml> for bool {
+    const TAG_NAME: TagName<'xml> = TagName::FieldName;
+
+    fn deserialize(deserializer: &mut Deserializer) -> Result<Self, Error> {
+        match deserializer.consume_next_type() {
+            EntityType::Element => deserializer.deserialize_bool(BoolVisitor),
+            EntityType::Attribute => deserializer.deserialize_attribute(BoolVisitor),
+        }
+    }
+}

instant-xml/src/lib.rs

@@ -5,10 +5,29 @@ use thiserror::Error;
 pub use xmlparser;
 
 pub use macros::{FromXml, ToXml};
+use parse::XmlParser;
 
+pub mod impls;
 #[doc(hidden)]
 pub mod parse;
 
+pub struct TagData<'xml> {
+    pub key: &'xml str,
+    pub attributes: Vec<(&'xml str, &'xml str)>,
+
+    // TODO: handle default namespace
+    pub default_namespace: Option<&'xml str>,
+
+    pub namespaces: Option<HashMap<&'xml str, &'xml str>>,
+    pub prefix: Option<&'xml str>,
+}
+
+pub enum XmlRecord<'xml> {
+    Open(TagData<'xml>),
+    Element(&'xml str),
+    Close(&'xml str),
+}
+
 pub trait ToXml {
     fn to_xml(&self) -> Result<String, Error> {
         let mut output = String::new();
@@ -181,8 +200,167 @@ pub struct FieldContext<'xml> {
     pub attribute: Option<FieldAttribute<'xml>>,
 }
 
+#[derive(Clone, PartialEq, Eq)]
+pub enum EntityType {
+    Element,
+    Attribute,
+}
+
+pub enum TagName<'xml> {
+    FieldName,
+    Custom(&'xml str),
+}
+
 pub trait FromXml<'xml>: Sized {
-    fn from_xml(input: &str) -> Result<Self, Error>;
+    const TAG_NAME: TagName<'xml>;
+
+    fn from_xml(input: &str) -> Result<Self, Error> {
+        let mut deserializer = Deserializer::new(input);
+        Self::deserialize(&mut deserializer)
+    }
+
+    fn deserialize(deserializer: &mut Deserializer) -> Result<Self, Error>;
+}
+
+pub trait Visitor<'xml>: Sized {
+    type Value;
+
+    fn visit_str(self, _value: &str) -> Result<Self::Value, Error> {
+        unimplemented!();
+    }
+
+    fn visit_struct<'a>(&self, _deserializer: &'a mut Deserializer) -> Result<Self::Value, Error> {
+        unimplemented!();
+    }
+}
+
+pub struct Deserializer<'xml> {
+    parser: XmlParser<'xml>,
+    namespaces: HashMap<&'xml str, &'xml str>,
+    tag_attributes: Vec<(&'xml str, &'xml str)>,
+    next_type: EntityType,
+}
+
+impl<'xml> Deserializer<'xml> {
+    pub fn new(input: &'xml str) -> Self {
+        Self {
+            parser: XmlParser::new(input),
+            namespaces: std::collections::HashMap::new(),
+            tag_attributes: Vec::new(),
+            next_type: EntityType::Element,
+        }
+    }
+
+    pub fn peek_next_tag(&mut self) -> Result<Option<XmlRecord>, Error> {
+        self.parser.peek_next_tag()
+    }
+
+    pub fn verify_namespace(&self, namespace_to_verify: &str) -> bool {
+        self.namespaces.get(namespace_to_verify).is_some()
+    }
+
+    pub fn peek_next_attribute(&self) -> Option<&(&'xml str, &'xml str)> {
+        self.tag_attributes.last()
+    }
+
+    pub fn deserialize_struct<V>(
+        &mut self,
+        visitor: V,
+        name: &str,
+        namespaces: &HashMap<&'xml str, &'xml str>,
+    ) -> Result<V::Value, Error>
+    where
+        V: Visitor<'xml>,
+    {
+        let new_namespaces = namespaces
+            .iter()
+            .filter(|(k, v)| self.namespaces.insert(k, v).is_none())
+            .collect::<Vec<_>>();
+
+        self.process_open_tag(name, namespaces)?;
+        let ret = visitor.visit_struct(self)?;
+
+        self.check_close_tag(name)?;
+        let _ = new_namespaces
+            .iter()
+            .map(|(k, _)| self.namespaces.remove(*k));
+
+        Ok(ret)
+    }
+
+    pub fn set_next_type_as_attribute(&mut self) -> Result<(), Error> {
+        if self.next_type == EntityType::Attribute {
+            return Err(Error::UnexpectedState);
+        }
+
+        self.next_type = EntityType::Attribute;
+        Ok(())
+    }
+
+    pub fn consume_next_type(&mut self) -> EntityType {
+        let ret = self.next_type.clone();
+        self.next_type = EntityType::Element;
+        ret
+    }
+
+    fn deserialize_bool<V>(&mut self, visitor: V) -> Result<V::Value, Error>
+    where
+        V: Visitor<'xml>,
+    {
+        self.parser.next();
+        match self.parser.next() {
+            Some(Ok(XmlRecord::Element(v))) => {
+                let ret = visitor.visit_str(v);
+                self.parser.next();
+                ret
+            }
+            _ => Err(Error::UnexpectedValue),
+        }
+    }
+
+    fn deserialize_attribute<V>(&mut self, visitor: V) -> Result<V::Value, Error>
+    where
+        V: Visitor<'xml>,
+    {
+        match self.tag_attributes.pop() {
+            Some((_, value)) => visitor.visit_str(value),
+            None => Err(Error::UnexpectedEndOfStream),
+        }
+    }
+
+    fn process_open_tag(
+        &mut self,
+        name: &str,
+        namespaces: &HashMap<&'xml str, &'xml str>,
+    ) -> Result<(), Error> {
+        let item = match self.parser.next() {
+            Some(Ok(XmlRecord::Open(item))) if item.key == name => item,
+            _ => return Err(Error::UnexpectedValue),
+        };
+
+        for (k, v) in item.namespaces.unwrap() {
+            match namespaces.get(k) {
+                Some(item) if *item != v => return Err(Error::UnexpectedPrefix),
+                None => return Err(Error::MissingdPrefix),
+                _ => (),
+            }
+        }
+
+        self.tag_attributes = item.attributes;
+        Ok(())
+    }
+
+    fn check_close_tag(&mut self, name: &str) -> Result<(), Error> {
+        let item = match self.parser.next() {
+            Some(item) => item?,
+            None => return Err(Error::MissingTag),
+        };
+
+        match item {
+            XmlRecord::Close(v) if v == name => Ok(()),
+            _ => Err(Error::UnexpectedTag),
+        }
+    }
 }
 
 pub trait FromXmlOwned: for<'xml> FromXml<'xml> {}
@@ -198,10 +376,24 @@ pub enum Error {
     Format(#[from] fmt::Error),
     #[error("parse: {0}")]
     Parse(#[from] xmlparser::Error),
+    #[error("other: {0}")]
+    Other(std::string::String),
     #[error("unexpected end of stream")]
     UnexpectedEndOfStream,
     #[error("unexpected value")]
     UnexpectedValue,
-    #[error("wrong prefix")]
-    WrongPrefix,
+    #[error("unexpected tag")]
+    UnexpectedTag,
+    #[error("missing tag")]
+    MissingTag,
+    #[error("missing value")]
+    MissingValue,
+    #[error("unexpected token")]
+    UnexpectedToken,
+    #[error("missing prefix")]
+    MissingdPrefix,
+    #[error("unexpected prefix")]
+    UnexpectedPrefix,
+    #[error("unexpected state")]
+    UnexpectedState,
 }

instant-xml/src/parse.rs

@@ -1,48 +1,134 @@
-use xmlparser::{ElementEnd, Token};
+use std::collections::HashMap;
+use std::iter::Peekable;
 
-use super::Error;
+use xmlparser::{ElementEnd, Token, Tokenizer};
 
-impl<'a> Parse for Option<Result<xmlparser::Token<'a>, xmlparser::Error>> {
-    fn element_start(self, ns: Option<&str>, tag: &str) -> Result<(), Error> {
-        match self {
-            Some(Ok(Token::ElementStart { prefix, local, .. })) => {
-                let prefix_ns = prefix.as_str();
-                let (has_prefix, expect_prefix) = (!prefix_ns.is_empty(), ns.is_some());
-                if has_prefix != expect_prefix {
-                    return dbg!(Err(Error::UnexpectedValue));
-                }
+use crate::Error;
+pub use crate::{TagData, XmlRecord};
 
-                if has_prefix && Some(prefix_ns) != ns {
-                    return dbg!(Err(Error::UnexpectedValue));
-                }
+pub struct XmlParser<'xml> {
+    stack: Vec<&'xml str>,
+    iter: Peekable<Tokenizer<'xml>>,
+}
 
-                if local.as_str() != tag {
-                    return dbg!(Err(Error::UnexpectedValue));
-                }
+impl<'a> XmlParser<'a> {
+    pub fn new(input: &'a str) -> XmlParser<'a> {
+        XmlParser {
+            stack: Vec::new(),
+            iter: Tokenizer::from(input).peekable(),
+        }
+    }
 
-                Ok(())
+    pub fn peek_next_tag(&mut self) -> Result<Option<XmlRecord>, Error> {
+        let item = match self.iter.peek() {
+            Some(v) => v,
+            None => return Ok(None),
+        };
+
+        match item {
+            Ok(Token::ElementStart { prefix, local, .. }) => {
+                let prefix = match prefix.is_empty() {
+                    true => None,
+                    false => Some(prefix.as_str()),
+                };
+
+                Ok(Some(XmlRecord::Open(TagData {
+                    key: local,
+                    attributes: Vec::new(),
+                    default_namespace: None,
+                    namespaces: None,
+                    prefix,
+                })))
             }
-            Some(Ok(_)) => Err(Error::UnexpectedValue),
-            Some(Err(err)) => Err(err.into()),
-            None => Err(Error::UnexpectedEndOfStream),
-        }
-    }
+            Ok(Token::ElementEnd {
+                end: ElementEnd::Close(..),
+                ..
+            }) => {
+                if self.stack.is_empty() {
+                    return Err(Error::UnexpectedEndOfStream);
+                }
 
-    fn element_end(self, _: Option<&str>, _: &str) -> Result<(), Error> {
-        match self {
-            Some(Ok(Token::ElementEnd { end, .. })) => match end {
-                ElementEnd::Open => todo!(),
-                ElementEnd::Close(_, _) => todo!(),
-                ElementEnd::Empty => Ok(()),
-            },
-            Some(Ok(_)) => Err(Error::UnexpectedValue),
-            Some(Err(err)) => Err(err.into()),
-            None => Err(Error::UnexpectedEndOfStream),
+                return Ok(Some(XmlRecord::Close(self.stack.last().unwrap())));
+            }
+            Ok(_) => Err(Error::UnexpectedToken),
+            Err(e) => Err(Error::Parse(*e)),
         }
     }
 }
 
-pub trait Parse {
-    fn element_start(self, ns: Option<&str>, tag: &str) -> Result<(), Error>;
-    fn element_end(self, ns: Option<&str>, tag: &str) -> Result<(), Error>;
+impl<'xml> Iterator for XmlParser<'xml> {
+    type Item = Result<XmlRecord<'xml>, Error>;
+
+    #[inline]
+    fn next(&mut self) -> Option<Self::Item> {
+        let mut key: Option<&str> = None;
+        let mut prefix_ret: Option<&str> = None;
+        let mut default_namespace = None;
+        let mut namespaces = HashMap::new();
+        let mut attributes = Vec::new();
+
+        loop {
+            let item = match self.iter.next() {
+                Some(v) => v,
+                None => return None,
+            };
+
+            match item {
+                Ok(Token::ElementStart { prefix, local, .. }) => {
+                    key = Some(local.as_str());
+                    prefix_ret = match prefix.is_empty() {
+                        true => None,
+                        false => Some(prefix.as_str()),
+                    };
+                }
+                Ok(Token::ElementEnd { end, .. }) => match end {
+                    ElementEnd::Open => {
+                        self.stack.push(key.unwrap());
+
+                        return Some(Ok(XmlRecord::Open(TagData {
+                            key: key.unwrap(),
+                            attributes,
+                            default_namespace,
+                            namespaces: Some(namespaces),
+                            prefix: prefix_ret,
+                        })));
+                    }
+                    ElementEnd::Close(_, v) => match self.stack.pop() {
+                        Some(last) if last == v.as_str() => {
+                            return Some(Ok(XmlRecord::Close(last)));
+                        }
+                        _ => return Some(Err(Error::UnexpectedValue)),
+                    },
+                    ElementEnd::Empty => {
+                        todo!();
+                    }
+                },
+                Ok(Token::Attribute {
+                    prefix,
+                    local,
+                    value,
+                    ..
+                }) => {
+                    if prefix.is_empty() && local.as_str() == "xmlns" {
+                        // Default namespace
+                        default_namespace = Some(value.as_str());
+                    } else if prefix.as_str() == "xmlns" {
+                        // Namespaces
+                        namespaces.insert(local.as_str(), value.as_str());
+                    } else if prefix.is_empty() {
+                        // Other attributes
+                        attributes.push((local.as_str(), value.as_str()));
+                    } else {
+                        // TODO: Can the attributes have the prefix?
+                        todo!();
+                    }
+                }
+                Ok(Token::Text { text }) => {
+                    return Some(Ok(XmlRecord::Element(text.as_str())));
+                }
+                Ok(_) => return Some(Err(Error::UnexpectedToken)),
+                Err(e) => return Some(Err(Error::Parse(e))),
+            }
+        }
+    }
 }

instant-xml/tests/all.rs

@@ -1,32 +1,26 @@
 use instant_xml::{FromXml, ToXml};
 
-#[derive(Debug, Eq, FromXml, PartialEq, ToXml)]
-struct Unit;
-
-#[derive(Debug, Eq, PartialEq, ToXml)]
-#[xml(namespace("URI", bar = "BAZ", foo = "BAR"))]
-struct StructWithCustomField {
-    test: Nested,
-}
-
-#[derive(Debug, Eq, PartialEq, ToXml)]
+#[derive(Debug, Eq, PartialEq, ToXml, FromXml)]
 struct Nested {
     #[xml(namespace(bar))]
     flag: bool,
 }
 
-#[derive(Debug, Eq, PartialEq, ToXml)]
-#[xml(namespace("URI", bar = "BAZ", foo = "BAR"))]
-struct StructWithCustomFieldWrongPrefix {
-    test: NestedWrongPrefix,
-}
-
 #[derive(Debug, Eq, PartialEq, ToXml)]
 struct NestedWrongPrefix {
     #[xml(namespace(dar))]
     flag: bool,
 }
 
+#[derive(Debug, Eq, PartialEq, ToXml)]
+struct Unit;
+
+#[test]
+fn unit() {
+    assert_eq!(Unit.to_xml().unwrap(), "<Unit></Unit>");
+    //assert_eq!(Unit::from_xml("<Unit/>").unwrap(), Unit);
+}
+
 #[derive(Debug, Eq, PartialEq, ToXml)]
 #[xml(namespace("URI", bar = "BAZ", foo = "BAR"))]
 struct StructWithNamedFields {
@@ -37,12 +31,6 @@ struct StructWithNamedFields {
     number: i32,
 }
 
-#[test]
-fn unit() {
-    assert_eq!(Unit.to_xml().unwrap(), "<Unit></Unit>");
-    assert_eq!(Unit::from_xml("<Unit/>").unwrap(), Unit);
-}
-
 #[test]
 fn struct_with_named_fields() {
     assert_eq!(
@@ -57,6 +45,12 @@ fn struct_with_named_fields() {
     );
 }
 
+#[derive(Debug, Eq, PartialEq, ToXml)]
+#[xml(namespace("URI", bar = "BAZ", foo = "BAR"))]
+struct StructWithCustomField {
+    test: Nested,
+}
+
 #[test]
 fn struct_with_custom_field() {
     assert_eq!(
@@ -72,6 +66,12 @@ fn struct_with_custom_field() {
     );
 }
 
+#[derive(Debug, Eq, PartialEq, ToXml)]
+#[xml(namespace("URI", bar = "BAZ", foo = "BAR"))]
+struct StructWithCustomFieldWrongPrefix {
+    test: NestedWrongPrefix,
+}
+
 #[test]
 #[should_panic]
 fn struct_with_custom_field_wrong_prefix() {
@@ -81,3 +81,39 @@ fn struct_with_custom_field_wrong_prefix() {
     .to_xml()
     .unwrap();
 }
+
+#[derive(Debug, Eq, PartialEq, FromXml)]
+#[xml(namespace("URI", bar = "BAZ", foo = "BAR"))]
+struct StructWithCustomFieldFromXml {
+    #[xml(namespace(bar))]
+    flag: bool,
+    #[xml(attribute)]
+    flag_attribute: bool,
+    test: Nested,
+}
+
+#[test]
+fn struct_with_custom_field_from_xml() {
+    assert_eq!(
+        StructWithCustomFieldFromXml::from_xml("<StructWithCustomFieldFromXml flag_attribute=\"true\" xmlns=\"URI\" xmlns:bar=\"BAZ\" xmlns:foo=\"BAR\"><bar:flag>false</bar:flag><Nested><flag>true</flag></Nested></StructWithCustomFieldFromXml>").unwrap(),
+        StructWithCustomFieldFromXml {
+            flag: false,
+            flag_attribute: true,
+            test: Nested { flag: true }
+        }
+    );
+    // Different order
+    assert_eq!(
+        StructWithCustomFieldFromXml::from_xml("<StructWithCustomFieldFromXml xmlns=\"URI\" xmlns:bar=\"BAZ\" xmlns:foo=\"BAR\" flag_attribute=\"true\"><Nested><flag>true</flag></Nested><flag>false</flag></StructWithCustomFieldFromXml>").unwrap(),
+        StructWithCustomFieldFromXml {
+            flag: false,
+            flag_attribute: true,
+            test: Nested { flag: true }
+        }
+    );
+
+    assert_eq!(
+        Nested::from_xml("<Nested><flag>true</flag></Nested>").unwrap(),
+        Nested { flag: true }
+    );
+}