implement element reading

Cargo.lock

@@ -46,9 +46,9 @@ checksum = "b048fb63fd8b5923fc5aa7b340d8e156aec7ec02f0c78fa8a6ddc2613f6f71de"
 
 [[package]]
 name = "bytes"
-version = "1.6.0"
+version = "1.8.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "514de17de45fdb8dc022b1a7975556c53c86f9f0aa5f534b98977b171857c2c9"
+checksum = "9ac0150caa2ae65ca5bd83f25c7de183dea78d4d366469f148435e2acfbad0da"
 
 [[package]]
 name = "cc"
@@ -62,6 +62,13 @@ version = "1.0.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "baf1de4339761588bc0619e3cbc0120ee582ebb74b53b4efbf79117bd2da40fd"
 
+[[package]]
+name = "circular"
+version = "0.3.0"
+dependencies = [
+ "bytes",
+]
+
 [[package]]
 name = "futures"
 version = "0.3.30"
@@ -265,6 +272,7 @@ dependencies = [
 name = "peanuts"
 version = "0.1.0"
 dependencies = [
+ "circular",
  "futures",
  "nom",
  "tokio",

Cargo.toml

@@ -6,6 +6,7 @@ edition = "2021"
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
 [dependencies]
+circular = { version = "0.3.0", path = "../circular" }
 futures = "0.3.30"
 nom = "7.1.3"
 tokio = { version = "1.36.0", features = ["io-util", "net", "io-std", "full"] }

src/element.rs

@@ -1,23 +1,32 @@
 // elements resemble a final tree, including inherited namespace information
 
-use std::collections::HashMap;
+use std::collections::{HashMap, HashSet};
+
+use crate::{
+    error::Error,
+    xml::{self, Attribute},
+};
 
 // when are namespaces names chosen then if they are automatically calculated
 // namespaces are held by readers and writers.
+#[derive(PartialEq, Eq, Hash, Clone)]
 pub struct Namespace {
-    prefix: Option<String>,
-    namespace: String,
+    pub prefix: Option<String>,
+    pub namespace: String,
 }
 
 // names are qualified, they contain a reference to the namespace (held within the reader/writer)
+#[derive(PartialEq, Eq, Hash, Clone)]
 pub struct Name {
-    namespace: String,
-    name: String,
+    pub namespace: Namespace,
+    pub name: String,
 }
 
-pub enum Node {
+pub enum Content {
     Element(Element),
     Text(String),
+    PI(String),
+    Comment(String),
 }
 
 // should this be a trait?
@@ -29,16 +38,35 @@ pub struct Element {
     // namespace: String,
     // hashmap of explicit namespace declarations on the element itself only
     // possibly not needed as can be calculated at write time depending on context and qualified namespace, and for reading, element validity and namespaces are kept track of by the reader.
-    pub namespace_decl: HashMap<Option<String>, String>,
+    pub namespace_decl: HashSet<Namespace>,
     // attributes can be in a different namespace than the element. how to make sure they are valid?
     // maybe include the namespace instead of or with the prefix
     // you can calculate the prefix from the namespaced name and the current writer context
     // you can validate the prefix and calculate the namespace from the current reader context
     // this results in readers and writers being able to return qualification errors as they aren't able to create elements until every part is qualified.
     pub attributes: HashMap<Name, String>,
-    pub children: Option<Vec<Node>>,
+    pub content: Vec<Content>,
 }
 
+// impl<'s> TryFrom<xml::Element<'s>> for Element<'s> {
+//     type Error = Error;
+
+//     fn try_from(xml_element: xml::Element) -> Result<Self, Self::Error> {
+//         match &xml_element {
+//             xml::Element::Empty(empty_elem_tag) => {
+//                 let namespace_decl;
+//                 let attributes;
+//                 empty_elem_tag
+//                     .attributes
+//                     .into_iter()
+//                     .filter(|attribute| matches!(attribute, Attribute::NamespaceDeclaration(_)));
+//                 todo!()
+//             }
+//             xml::Element::NotEmpty(stag, content, etag) => todo!(),
+//         }
+//     }
+// }
+
 // example of deriving an element:
 
 // #[derive(XMLWrite, XMLRead)]

src/error.rs

@@ -1,9 +1,18 @@
-use std::str::Utf8Error;
+use std::{num::ParseIntError, str::Utf8Error};
+
+use crate::element::{Name, Namespace};
 
 pub enum Error {
     ReadError(std::io::Error),
     Utf8Error(Utf8Error),
     ParseError(String),
+    EntityProcessError(String),
+    // TODO: better choice for failures than string
+    InvalidCharRef(String),
+    DuplicateNameSpace(Namespace),
+    DuplicateAttribute(String),
+    UnqualifiedNamespace(String),
+    MismatchedEndTag(String, String),
 }
 
 impl From<std::io::Error> for Error {
@@ -17,3 +26,9 @@ impl From<Utf8Error> for Error {
         Self::Utf8Error(e)
     }
 }
+
+impl From<ParseIntError> for Error {
+    fn from(e: ParseIntError) -> Self {
+        Self::InvalidCharRef(e.to_string())
+    }
+}

src/lib.rs

@@ -3,3 +3,5 @@ mod error;
 mod reader;
 mod writer;
 pub mod xml;
+
+pub type Result<T> = std::result::Result<T, error::Error>;

src/main.rs

@@ -5,12 +5,87 @@ use peanuts::xml::Document;
 #[tokio::main]
 async fn main() {
     let (rest, document) = Document::parse(
-        "<?xml version=\"1.0\"?>
-<TEST>
-  <block1>Background Mark 1</block1>
-  <block2>Background Mark 2</block2>
-  <block3>Background Mark 3</block3>
-</TEST>ahsdkjlfhasdlkjfhkljh
+        "<?xml version='1.0' encoding='UTF-8'?>
+
+   <xs:schema
+       xmlns:xs='http://www.w3.org/2001/XMLSchema'
+       targetNamespace='http://etherx.jabber.org/streams'
+       xmlns='http://etherx.jabber.org/streams'
+       elementFormDefault='unqualified'>
+
+     <xs:import namespace='jabber:client'/>
+     <xs:import namespace='jabber:server'/>
+     <xs:import namespace='urn:ietf:params:xml:ns:xmpp-sasl'/>
+     <xs:import namespace='urn:ietf:params:xml:ns:xmpp-streams'/>
+     <xs:import namespace='urn:ietf:params:xml:ns:xmpp-tls'/>
+
+     <xs:element name='stream'>
+       <xs:complexType>
+         <xs:sequence xmlns:client='jabber:client'
+                      xmlns:server='jabber:server'>
+           <xs:element ref='features'
+                       minOccurs='0'
+                       maxOccurs='1'/>
+           <xs:any namespace='urn:ietf:params:xml:ns:xmpp-tls'
+                   minOccurs='0'
+                   maxOccurs='1'/>
+           <xs:any namespace='urn:ietf:params:xml:ns:xmpp-sasl'
+                   minOccurs='0'
+                   maxOccurs='1'/>
+           <xs:any namespace='##other'
+                   minOccurs='0'
+                   maxOccurs='unbounded'
+                   processContents='lax'/>
+           <xs:choice minOccurs='0' maxOccurs='1'>
+             <xs:choice minOccurs='0' maxOccurs='unbounded'>
+               <xs:element ref='client:message'/>
+               <xs:element ref='client:presence'/>
+               <xs:element ref='client:iq'/>
+             </xs:choice>
+             <xs:choice minOccurs='0' maxOccurs='unbounded'>
+               <xs:element ref='server:message'/>
+               <xs:element ref='server:presence'/>
+               <xs:element ref='server:iq'/>
+             </xs:choice>
+           </xs:choice>
+           <xs:element ref='error' minOccurs='0' maxOccurs='1'/>
+         </xs:sequence>
+         <xs:attribute name='from' type='xs:string' use='optional'/>
+         <xs:attribute name='id' type='xs:string' use='optional'/>
+         <xs:attribute name='to' type='xs:string' use='optional'/>
+         <xs:attribute name='version' type='xs:decimal' use='optional'/>
+         <xs:attribute ref='xml:lang' use='optional'/>
+         <xs:anyAttribute namespace='##other' processContents='lax'/>
+       </xs:complexType>
+     </xs:element>
+
+     <xs:element name='features'>
+       <xs:complexType>
+         <xs:sequence>
+           <xs:any namespace='##other'
+                   minOccurs='0'
+                   maxOccurs='unbounded'
+                   processContents='lax'/>
+         </xs:sequence>
+       </xs:complexType>
+     </xs:element>
+
+     <xs:element name='error'>
+       <xs:complexType>
+         <xs:sequence  xmlns:err='urn:ietf:params:xml:ns:xmpp-streams'>
+           <xs:group   ref='err:streamErrorGroup'/>
+           <xs:element ref='err:text'
+                       minOccurs='0'
+                       maxOccurs='1'/>
+           <xs:any     namespace='##other'
+                       minOccurs='0'
+                       maxOccurs='1'
+                       processContents='lax'/>
+         </xs:sequence>
+       </xs:complexType>
+     </xs:element>
+
+   </xs:schema>asdf
 ",
     )
     .unwrap();

src/reader.rs

@@ -1,31 +1,348 @@
+use circular::Buffer;
 use futures::Stream;
 use nom::Err;
-use std::{collections::BTreeMap, str};
-use tokio::io::AsyncBufReadExt;
+use std::{
+    collections::{BTreeMap, HashMap, HashSet},
+    path::Prefix,
+    str::{self, FromStr},
+};
+use tokio::io::{AsyncBufRead, AsyncBufReadExt, AsyncRead, AsyncReadExt};
+
+static MAX_STANZA_SIZE: usize = 65536;
 
 use crate::{
-    element::{Element, Name, Namespace},
+    element::{Content, Element, Name, Namespace},
     error::Error,
+    xml::{self, parsers::Parser},
+    Result,
 };
 
 /// streaming reader that tracks depth and available namespaces at current depth
 pub struct Reader<R> {
     inner: R,
+    buffer: Buffer,
     // holds which tags we are in atm over depth
+    // to have names reference namespaces could
     depth: Vec<Name>,
-    namespaces: Vec<(usize, Namespace)>,
+    namespaces: Vec<HashSet<Namespace>>,
 }
 
 impl<R> Reader<R> {
     pub fn new(reader: R) -> Self {
         Self {
             inner: reader,
+            buffer: Buffer::with_capacity(MAX_STANZA_SIZE),
             depth: Vec::new(),
             namespaces: Vec::new(),
         }
     }
 }
 
+impl<R> Reader<R>
+where
+    R: AsyncRead + Unpin,
+{
+    async fn read_buf(&mut self) -> Result<usize> {
+        Ok(self.inner.read_buf(&mut self.buffer).await?)
+    }
+
+    async fn read_element<'s>(&'s mut self) -> Result<Element> {
+        self.read_buf().await?;
+        let mut input = str::from_utf8(self.buffer.data())?;
+        loop {
+            match xml::Element::parse(input) {
+                Ok((rest, e)) => {
+                    let len = self.buffer.available_data() - rest.as_bytes().len();
+                    let element = Reader::<R>::element_from_xml(&mut self.namespaces, e)?;
+                    self.buffer.consume(len);
+                    return Ok(element);
+                }
+                std::result::Result::Err(e) => match e {
+                    Err::Incomplete(_) => {
+                        self.read_buf().await?;
+                        input = str::from_utf8(self.buffer.data())?;
+                    }
+                    // TODO: better error
+                    Err::Error(e) => return Err(Error::ParseError(e.to_string())),
+                    Err::Failure(e) => return Err(Error::ParseError(e.to_string())),
+                },
+            }
+        }
+    }
+}
+
+impl<R> Reader<R> {
+    fn element_from_xml(
+        namespaces: &mut Vec<HashSet<Namespace>>,
+        element: xml::Element,
+    ) -> Result<Element> {
+        match element {
+            xml::Element::Empty(empty_elem_tag) => {
+                let mut namespace_declarations = HashSet::new();
+                for (prefix, namespace) in
+                    empty_elem_tag.attributes.iter().filter_map(|attribute| {
+                        if let xml::Attribute::NamespaceDeclaration { ns_name, value } = attribute {
+                            Some((ns_name, value))
+                        } else {
+                            None
+                        }
+                    })
+                {
+                    let prefix = match prefix {
+                        xml::NSAttName::PrefixedAttName(prefixed_att_name) => {
+                            Some(prefixed_att_name.to_string())
+                        }
+                        xml::NSAttName::DefaultAttName => None,
+                    };
+                    let namespace = Namespace {
+                        prefix,
+                        namespace: namespace.process()?,
+                    };
+                    if !namespace_declarations.insert(namespace.clone()) {
+                        return Err(Error::DuplicateNameSpace(namespace));
+                    }
+                }
+
+                // all namespaces available to the element (from both parent elements and element itself)
+                let namespace_stack: Vec<&Namespace> = namespaces
+                    .iter()
+                    .flatten()
+                    .chain(namespace_declarations.iter())
+                    .collect();
+
+                let mut attributes = HashMap::new();
+
+                for (q_name, value) in empty_elem_tag.attributes.iter().filter_map(|attribute| {
+                    if let xml::Attribute::Attribute { name, value } = attribute {
+                        Some((name, value))
+                    } else {
+                        None
+                    }
+                }) {
+                    let namespace;
+                    let attribute_name;
+                    match q_name {
+                        xml::QName::PrefixedName(prefixed_name) => {
+                            namespace = namespace_stack.iter().rfind(|namespace| {
+                                namespace.prefix.as_deref() == Some(**prefixed_name.prefix)
+                            });
+                            attribute_name = prefixed_name.local_part.to_string();
+                        }
+                        xml::QName::UnprefixedName(unprefixed_name) => {
+                            namespace = namespace_stack
+                                .iter()
+                                .rfind(|namespace| namespace.prefix == None);
+                            attribute_name = unprefixed_name.to_string();
+                        }
+                    }
+                    if let Some(namespace) = namespace {
+                        let namespace = (*namespace).clone();
+                        let name = Name {
+                            namespace,
+                            name: attribute_name,
+                        };
+                        let value = value.process()?;
+                        if let Some(_value) = attributes.insert(name, value) {
+                            return Err(Error::DuplicateAttribute(q_name.to_string()));
+                        }
+                    } else {
+                        return Err(Error::UnqualifiedNamespace(q_name.to_string()));
+                    }
+                }
+
+                let name;
+                let namespace;
+                match &empty_elem_tag.name {
+                    xml::QName::PrefixedName(prefixed_name) => {
+                        namespace = namespace_stack.iter().rfind(|namespace| {
+                            namespace.prefix.as_deref() == Some(**prefixed_name.prefix)
+                        });
+                        name = prefixed_name.local_part.to_string();
+                    }
+                    xml::QName::UnprefixedName(unprefixed_name) => {
+                        namespace = namespace_stack
+                            .iter()
+                            .rfind(|namespace| namespace.prefix == None);
+                        name = unprefixed_name.to_string();
+                    }
+                }
+
+                let namespace = (*namespace
+                    .ok_or_else(|| Error::UnqualifiedNamespace(empty_elem_tag.name.to_string()))?)
+                .clone();
+
+                let name = Name { namespace, name };
+
+                return Ok(Element {
+                    name,
+                    namespace_decl: namespace_declarations,
+                    attributes,
+                    content: Vec::new(),
+                });
+            }
+            xml::Element::NotEmpty(s_tag, content, e_tag) => {
+                if s_tag.name != e_tag.name {
+                    return Err(Error::MismatchedEndTag(
+                        s_tag.name.to_string(),
+                        e_tag.name.to_string(),
+                    ));
+                }
+                let mut namespace_declarations = HashSet::new();
+                for (prefix, namespace) in s_tag.attributes.iter().filter_map(|attribute| {
+                    if let xml::Attribute::NamespaceDeclaration { ns_name, value } = attribute {
+                        Some((ns_name, value))
+                    } else {
+                        None
+                    }
+                }) {
+                    let prefix = match prefix {
+                        xml::NSAttName::PrefixedAttName(prefixed_att_name) => {
+                            Some(prefixed_att_name.to_string())
+                        }
+                        xml::NSAttName::DefaultAttName => None,
+                    };
+                    let namespace = Namespace {
+                        prefix,
+                        namespace: namespace.process()?,
+                    };
+                    if !namespace_declarations.insert(namespace.clone()) {
+                        return Err(Error::DuplicateNameSpace(namespace));
+                    }
+                }
+
+                // all namespaces available to the element (from both parent elements and element itself)
+                let namespace_stack: Vec<&Namespace> = namespaces
+                    .iter()
+                    .flatten()
+                    .chain(namespace_declarations.iter())
+                    .collect();
+
+                let mut attributes = HashMap::new();
+
+                for (q_name, value) in s_tag.attributes.iter().filter_map(|attribute| {
+                    if let xml::Attribute::Attribute { name, value } = attribute {
+                        Some((name, value))
+                    } else {
+                        None
+                    }
+                }) {
+                    let namespace;
+                    let attribute_name;
+                    match q_name {
+                        xml::QName::PrefixedName(prefixed_name) => {
+                            namespace = namespace_stack.iter().rfind(|namespace| {
+                                namespace.prefix.as_deref() == Some(**prefixed_name.prefix)
+                            });
+                            attribute_name = prefixed_name.local_part.to_string();
+                        }
+                        xml::QName::UnprefixedName(unprefixed_name) => {
+                            namespace = namespace_stack
+                                .iter()
+                                .rfind(|namespace| namespace.prefix == None);
+                            attribute_name = unprefixed_name.to_string();
+                        }
+                    }
+                    if let Some(namespace) = namespace {
+                        let namespace = (*namespace).clone();
+                        let name = Name {
+                            namespace,
+                            name: attribute_name,
+                        };
+                        let value = value.process()?;
+                        if let Some(_value) = attributes.insert(name, value) {
+                            return Err(Error::DuplicateAttribute(q_name.to_string()));
+                        }
+                    } else {
+                        return Err(Error::UnqualifiedNamespace(q_name.to_string()));
+                    }
+                }
+
+                let name;
+                let namespace;
+                match &s_tag.name {
+                    xml::QName::PrefixedName(prefixed_name) => {
+                        namespace = namespace_stack.iter().rfind(|namespace| {
+                            namespace.prefix.as_deref() == Some(**prefixed_name.prefix)
+                        });
+                        name = prefixed_name.local_part.to_string();
+                    }
+                    xml::QName::UnprefixedName(unprefixed_name) => {
+                        namespace = namespace_stack
+                            .iter()
+                            .rfind(|namespace| namespace.prefix == None);
+                        name = unprefixed_name.to_string();
+                    }
+                }
+
+                let namespace = (*namespace
+                    .ok_or_else(|| Error::UnqualifiedNamespace(s_tag.name.to_string()))?)
+                .clone();
+
+                let name = Name { namespace, name };
+
+                namespaces.push(namespace_declarations.clone());
+
+                let content = Self::content_from_xml(namespaces, content)?;
+
+                namespaces.pop();
+
+                return Ok(Element {
+                    name,
+                    namespace_decl: namespace_declarations,
+                    attributes,
+                    content,
+                });
+            }
+        }
+    }
+
+    fn content_from_xml(
+        namespaces: &mut Vec<HashSet<Namespace>>,
+        element: xml::Content,
+    ) -> Result<Vec<Content>> {
+        let mut content = Vec::new();
+        let mut text = element.char_data.map(|str| String::from(*str));
+        for (content_item, char_data) in element.content {
+            match content_item {
+                xml::ContentItem::Element(element) => {
+                    text.map(|text| content.push(Content::Text(text)));
+                    content.push(Content::Element(Self::element_from_xml(
+                        namespaces, element,
+                    )?));
+                    text = char_data.map(|str| String::from(*str));
+                }
+                xml::ContentItem::Reference(reference) => {
+                    let data = reference.process()?;
+                    if let Some(text) = &mut text {
+                        text.push(data)
+                    } else {
+                        text = Some(String::from(data))
+                    }
+                    char_data.map(|char_data| text.as_mut().map(|s| s.push_str(*char_data)));
+                }
+                xml::ContentItem::CDSect(cd_sect) => {
+                    if let Some(text) = &mut text {
+                        text.push_str(**cd_sect)
+                    } else {
+                        text = Some(String::from(**cd_sect))
+                    }
+                    char_data.map(|char_data| text.as_mut().map(|s| s.push_str(*char_data)));
+                }
+                // TODO: is this important?
+                xml::ContentItem::PI(pi) => {
+                    char_data.map(|char_data| text.as_mut().map(|s| s.push_str(*char_data)));
+                }
+                // TODO: comments?
+                xml::ContentItem::Comment(comment) => {
+                    char_data.map(|char_data| text.as_mut().map(|s| s.push_str(*char_data)));
+                }
+            }
+        }
+        text.map(|text| content.push(Content::Text(text)));
+        todo!()
+    }
+}
+
 // impl<R> Reader<R>
 // where
 //     R: AsyncBufReadExt + Unpin,

src/xml/mod.rs

@@ -1,4 +1,6 @@
-use std::char;
+use std::{char, ops::Deref};
+
+use crate::error::Error;
 
 pub mod composers;
 pub mod parsers;
@@ -14,40 +16,91 @@ pub enum NSAttName<'s> {
 #[derive(Clone, Debug)]
 pub struct PrefixedAttName<'s>(NCName<'s>);
 
+impl<'s> Deref for PrefixedAttName<'s> {
+    type Target = NCName<'s>;
+
+    fn deref(&self) -> &Self::Target {
+        &self.0
+    }
+}
+
 /// [3]   	DefaultAttName	   ::=   	'xmlns';
 #[derive(Clone, Debug)]
 pub struct DefaultAttName;
 
 /// [4]   	NCName	   ::=   	Name - (Char* ':' Char*)
-#[derive(Clone, Debug)]
+#[derive(Clone, Debug, PartialEq, Eq)]
 pub struct NCName<'s>(&'s str);
 
+impl<'s> Deref for NCName<'s> {
+    type Target = &'s str;
+
+    fn deref(&self) -> &Self::Target {
+        &self.0
+    }
+}
+
 /// [7]   	QName	   ::=   	PrefixedName | UnprefixedName
-#[derive(Clone, Debug)]
+#[derive(Clone, Debug, PartialEq, Eq)]
 pub enum QName<'s> {
     PrefixedName(PrefixedName<'s>),
     UnprefixedName(UnprefixedName<'s>),
 }
 
+impl<'s> ToString for QName<'s> {
+    fn to_string(&self) -> String {
+        match self {
+            QName::PrefixedName(prefixed_name) => {
+                format!("{}:{}", **prefixed_name.prefix, **prefixed_name.local_part)
+            }
+            QName::UnprefixedName(unprefixed_name) => unprefixed_name.to_string(),
+        }
+    }
+}
+
 /// [8]   	PrefixedName	   ::=   	Prefix ':' LocalPart
-#[derive(Clone, Debug)]
+#[derive(Clone, Debug, PartialEq, Eq)]
 pub struct PrefixedName<'s> {
-    prefix: Prefix<'s>,
-    local_part: LocalPart<'s>,
+    pub(crate) prefix: Prefix<'s>,
+    pub(crate) local_part: LocalPart<'s>,
 }
 
 /// [9]   	UnprefixedName	   ::=   	LocalPart
-#[derive(Clone, Debug)]
+#[derive(Clone, Debug, PartialEq, Eq)]
 pub struct UnprefixedName<'s>(LocalPart<'s>);
 
+impl<'s> Deref for UnprefixedName<'s> {
+    type Target = LocalPart<'s>;
+
+    fn deref(&self) -> &Self::Target {
+        &self.0
+    }
+}
+
 /// [10]   	Prefix	   ::=   	NCName
-#[derive(Clone, Debug)]
+#[derive(Clone, Debug, PartialEq, Eq)]
 pub struct Prefix<'s>(NCName<'s>);
 
+impl<'s> Deref for Prefix<'s> {
+    type Target = NCName<'s>;
+
+    fn deref(&self) -> &Self::Target {
+        &self.0
+    }
+}
+
 /// [11]   	LocalPart	   ::=   	NCName
-#[derive(Clone, Debug)]
+#[derive(Clone, Debug, PartialEq, Eq)]
 pub struct LocalPart<'s>(NCName<'s>);
 
+impl<'s> Deref for LocalPart<'s> {
+    type Target = NCName<'s>;
+
+    fn deref(&self) -> &Self::Target {
+        &self.0
+    }
+}
+
 // xml spec
 
 /// [1]   	document	   ::=   	prolog element Misc*
@@ -57,6 +110,14 @@ pub type Document<'s> = (Prolog<'s>, Element<'s>, Vec<Misc<'s>>);
 #[repr(transparent)]
 pub struct Char(char);
 
+impl Deref for Char {
+    type Target = char;
+
+    fn deref(&self) -> &Self::Target {
+        &self.0
+    }
+}
+
 /// [3]   	S	   ::=   	(#x20 | #x9 | #xD | #xA)+
 #[derive(Clone)]
 #[repr(transparent)]
@@ -66,28 +127,76 @@ pub struct S;
 #[repr(transparent)]
 pub struct NameStartChar(char);
 
+impl Deref for NameStartChar {
+    type Target = char;
+
+    fn deref(&self) -> &Self::Target {
+        &self.0
+    }
+}
+
 /// [4a]   	NameChar	   ::=   	NameStartChar | "-" | "." | [0-9] | #xB7 | [#x0300-#x036F] | [#x203F-#x2040]
 #[repr(transparent)]
 pub struct NameChar(char);
 
+impl Deref for NameChar {
+    type Target = char;
+
+    fn deref(&self) -> &Self::Target {
+        &self.0
+    }
+}
+
 /// [5]   	Name	   ::=   	NameStartChar (NameChar)*
 #[derive(Debug, Clone, PartialEq, Eq)]
 #[repr(transparent)]
 pub struct Name<'s>(&'s str);
 
+impl<'s> Deref for Name<'s> {
+    type Target = &'s str;
+
+    fn deref(&self) -> &Self::Target {
+        &self.0
+    }
+}
+
 /// [6]   	Names	   ::=   	Name (#x20 Name)*
 #[repr(transparent)]
 pub struct Names<'s>(Vec<Name<'s>>);
 
+impl<'s> Deref for Names<'s> {
+    type Target = Vec<Name<'s>>;
+
+    fn deref(&self) -> &Self::Target {
+        &self.0
+    }
+}
+
 /// [7]   	Nmtoken	   ::=   	(NameChar)+
 #[derive(Debug, Clone)]
 #[repr(transparent)]
 pub struct Nmtoken<'s>(&'s str);
 
+impl<'s> Deref for Nmtoken<'s> {
+    type Target = &'s str;
+
+    fn deref(&self) -> &Self::Target {
+        &self.0
+    }
+}
+
 /// [8]   	Nmtokens	   ::=   	Nmtoken (#x20 Nmtoken)*
 #[repr(transparent)]
 pub struct Nmtokens<'s>(Vec<Nmtoken<'s>>);
 
+impl<'s> Deref for Nmtokens<'s> {
+    type Target = Vec<Nmtoken<'s>>;
+
+    fn deref(&self) -> &Self::Target {
+        &self.0
+    }
+}
+
 #[derive(Clone, Debug)]
 pub enum EntityValueData<'s> {
     String(&'s str),
@@ -115,6 +224,24 @@ pub enum AttValue<'s> {
     SingleQuoted(Vec<AttValueData<'s>>),
 }
 
+impl<'s> AttValue<'s> {
+    pub fn process(&self) -> crate::Result<String> {
+        let mut output = String::new();
+        let data;
+        match self {
+            AttValue::DoubleQuoted(vec) => data = vec,
+            AttValue::SingleQuoted(vec) => data = vec,
+        }
+        for data in data {
+            match data {
+                AttValueData::String(s) => output.push_str(s),
+                AttValueData::Reference(reference) => output.push(reference.process()?),
+            }
+        }
+        Ok(output)
+    }
+}
+
 /// [11]   	SystemLiteral	   ::=   	('"' [^"]* '"') | ("'" [^']* "'")
 #[derive(Debug)]
 pub enum SystemLiteral<'s> {
@@ -138,11 +265,27 @@ pub struct PubidChar(char);
 #[repr(transparent)]
 pub struct CharData<'s>(&'s str);
 
+impl<'s> Deref for CharData<'s> {
+    type Target = &'s str;
+
+    fn deref(&self) -> &Self::Target {
+        &self.0
+    }
+}
+
 /// [15]    Comment	   ::=   	'<!--' ((Char - '-') | ('-' (Char - '-')))* '-->'
 #[derive(Clone, Debug, PartialEq, Eq)]
 #[repr(transparent)]
 pub struct Comment<'s>(&'s str);
 
+impl<'s> Deref for Comment<'s> {
+    type Target = &'s str;
+
+    fn deref(&self) -> &Self::Target {
+        &self.0
+    }
+}
+
 /// [16]   	PI	   ::=   	'<?' PITarget (S (Char* - (Char* '?>' Char*)))? '?>'
 #[derive(Clone, Debug)]
 pub struct PI<'s> {
@@ -160,6 +303,14 @@ pub struct PITarget<'s>(Name<'s>);
 #[repr(transparent)]
 pub struct CDSect<'s>(CData<'s>);
 
+impl<'s> Deref for CDSect<'s> {
+    type Target = CData<'s>;
+
+    fn deref(&self) -> &Self::Target {
+        &self.0
+    }
+}
+
 /// [19]   	CDStart	   ::=   	'<![CDATA['
 #[derive(Clone, Debug, PartialEq, Eq)]
 pub struct CDStart;
@@ -169,6 +320,14 @@ pub struct CDStart;
 #[repr(transparent)]
 pub struct CData<'s>(&'s str);
 
+impl<'s> Deref for CData<'s> {
+    type Target = &'s str;
+
+    fn deref(&self) -> &Self::Target {
+        &self.0
+    }
+}
+
 /// [21]   	CDEnd	   ::=   	']]>'
 #[derive(Clone, Debug, PartialEq, Eq)]
 pub struct CDEnd;
@@ -286,8 +445,8 @@ pub enum Element<'s> {
 /// [40]   	STag	   ::=   	'<' Name (S Attribute)* S? '>'
 #[derive(Debug, Clone)]
 pub struct STag<'s> {
-    name: QName<'s>,
-    attributes: Vec<Attribute<'s>>,
+    pub(crate) name: QName<'s>,
+    pub(crate) attributes: Vec<Attribute<'s>>,
 }
 
 /// [15]   	Attribute	   ::=   	NSAttName Eq AttValue | QName Eq AttValue
@@ -309,7 +468,7 @@ pub enum Attribute<'s> {
 /// [42]   	ETag	   ::=   	'</' Name S? '>'
 #[derive(Debug, Clone)]
 pub struct ETag<'s> {
-    name: QName<'s>,
+    pub(crate) name: QName<'s>,
 }
 
 #[derive(Debug, Clone)]
@@ -324,16 +483,16 @@ pub enum ContentItem<'s> {
 /// [43]   	content	   ::=   	CharData? ((element | Reference | CDSect | PI | Comment) CharData?)*
 #[derive(Debug, Clone)]
 pub struct Content<'s> {
-    char_data: Option<CharData<'s>>,
-    content: Vec<(ContentItem<'s>, Option<CharData<'s>>)>,
+    pub(crate) char_data: Option<CharData<'s>>,
+    pub(crate) content: Vec<(ContentItem<'s>, Option<CharData<'s>>)>,
 }
 
 /// [14]   	EmptyElemTag	   ::=   	'<' QName (S Attribute)* S? '/>'
 /// [44]   	EmptyElemTag	   ::=   	'<' Name (S Attribute)* S? '/>'	[WFC: Unique Att Spec]
 #[derive(Debug, Clone)]
 pub struct EmptyElemTag<'s> {
-    name: QName<'s>,
-    attributes: Vec<Attribute<'s>>,
+    pub(crate) name: QName<'s>,
+    pub(crate) attributes: Vec<Attribute<'s>>,
 }
 
 /// [17]   	elementdecl	   ::=   	'<!ELEMENT' S QName S contentspec S? '>'
@@ -503,6 +662,32 @@ pub enum CharRef<'s> {
     Hexadecimal(&'s str),
 }
 
+impl<'s> CharRef<'s> {
+    pub fn process(&self) -> crate::Result<char> {
+        let int: u32;
+        match self {
+            CharRef::Decimal(dec) => {
+                int = dec.parse()?;
+            }
+            CharRef::Hexadecimal(hex) => {
+                int = <u32>::from_str_radix(hex, 16)?;
+            }
+        }
+        let c = std::char::from_u32(int);
+
+        let c = c.ok_or_else(|| Error::InvalidCharRef(int.to_string()))?;
+        if matches!(c, '\u{9}' | '\u{A}' | '\u{D}' | '\u{20}'..='\u{D7FF}' | '\u{E000}'..='\u{FFFD}' | '\u{10000}'..='\u{10FFFF}')
+        {
+            return Ok(c);
+        } else {
+            return Err(Error::InvalidCharRef(format!(
+                "{} is not a valid xml char",
+                c
+            )));
+        };
+    }
+}
+
 /// [67]   	Reference	   ::=   	EntityRef | CharRef
 #[derive(Clone, Debug)]
 pub enum Reference<'s> {
@@ -510,10 +695,34 @@ pub enum Reference<'s> {
     CharRef(CharRef<'s>),
 }
 
+impl<'s> Reference<'s> {
+    pub fn process(&self) -> crate::Result<char> {
+        match self {
+            Reference::EntityRef(entity_ref) => match *entity_ref.deref().deref() {
+                "amp" => Ok('&'),
+                "lt" => Ok('<'),
+                "gt" => Ok('>'),
+                "apos" => Ok('\''),
+                "quot" => Ok('"'),
+                e => return Err(Error::EntityProcessError(e.to_string())),
+            },
+            Reference::CharRef(char_ref) => Ok(char_ref.process()?),
+        }
+    }
+}
+
 /// [68]   	EntityRef	   ::=   	'&' Name ';'
 #[derive(Clone, Debug)]
 pub struct EntityRef<'s>(Name<'s>);
 
+impl<'s> Deref for EntityRef<'s> {
+    type Target = Name<'s>;
+
+    fn deref(&self) -> &Self::Target {
+        &self.0
+    }
+}
+
 /// [69]   	PEReference	   ::=   	'%' Name ';'
 #[derive(Clone, Debug)]
 #[repr(transparent)]