WIP: write start tag of element

4 files changed, 163 insertions, 19 deletions

diff --git a/src/element.rs b/src/element.rs
index 6d2a6b7..d883c04 100644
--- a/src/element.rs
+++ b/src/element.rs
@@ -1,10 +1,14 @@
 // elements resemble a final tree, including inherited namespace information
 
-use std::collections::{HashMap, HashSet};
+use std::{
+    collections::{HashMap, HashSet},
+    convert::Infallible,
+    str::FromStr,
+};
 
 use crate::{
     error::Error,
-    xml::{self, Attribute},
+    xml::{self, parsers_complete::Parser, Attribute},
 };
 
 // when are namespaces names chosen then if they are automatically calculated
diff --git a/src/error.rs b/src/error.rs
index fcf43eb..69993ed 100644
--- a/src/error.rs
+++ b/src/error.rs
@@ -16,6 +16,7 @@ pub enum Error {
     MismatchedEndTag(Name, Name),
     NotInElement(String),
     ExtraData(String),
+    UndeclaredNamespace(String),
 }
 
 impl From<std::io::Error> for Error {
diff --git a/src/writer.rs b/src/writer.rs
index 21d5fe0..9e770c7 100644
--- a/src/writer.rs
+++ b/src/writer.rs
@@ -1,4 +1,4 @@
-use std::collections::HashSet;
+use std::{collections::HashSet, str::FromStr};
 
 use futures::Sink;
 use tokio::io::AsyncWrite;
@@ -7,6 +7,7 @@ use crate::{
     element::{Element, Name, NamespaceDeclaration},
     error::Error,
     xml::{self, composers::Composer, parsers_complete::Parser, ETag},
+    Result,
 };
 
 // pub struct Writer<W, C = Composer> {
@@ -17,17 +18,68 @@ pub struct Writer<W> {
 }
 
 impl<W: AsyncWrite + Unpin> Writer<W> {
-    pub async fn write(&mut self, element: Element) -> Result<(), Error> {
+    pub async fn write(&mut self, element: Element) -> Result<()> {
         todo!()
     }
 
-    pub async fn write_start(&mut self, element: Element) -> Result<(), Error> {
-        todo!()
+    pub async fn write_start(&mut self, element: Element) -> Result<()> {
+        let mut namespace_declarations_stack: Vec<_> = self
+            .namespace_declarations
+            .iter()
+            .flatten()
+            .chain(&element.namespace_declarations)
+            .collect();
+        let name_namespace_declaration = namespace_declarations_stack
+            .iter()
+            .rfind(|namespace_declaration| {
+                namespace_declaration.namespace == element.name.namespace
+            })
+            .ok_or(Error::UndeclaredNamespace(element.name.namespace.clone()))?;
+        let prefix = &name_namespace_declaration.prefix;
+        let name;
+        if let Some(prefix) = &prefix {
+            name = xml::QName::PrefixedName(xml::PrefixedName {
+                prefix: xml::Prefix::parse_full(prefix)?,
+                local_part: xml::LocalPart::parse_full(&element.name.local_name)?,
+            })
+        } else {
+            name = xml::QName::UnprefixedName(xml::UnprefixedName::parse_full(
+                &element.name.local_name,
+            )?)
+        }
+
+        namespace_declarations_stack.push(name_namespace_declaration);
+
+        let mut attributes = Vec::new();
+
+        for namespace_declaration in &element.namespace_declarations {
+            let ns_name = namespace_declaration
+                .prefix
+                .as_ref()
+                .map(|prefix| -> Result<_> {
+                    Ok(xml::NSAttName::PrefixedAttName(
+                        xml::PrefixedAttName::parse_full(&prefix)?,
+                    ))
+                })
+                .unwrap_or(Ok(xml::NSAttName::DefaultAttName))?;
+            let value = xml::AttValue::from(namespace_declaration.namespace.as_str());
+            let xml_attribute = xml::Attribute::NamespaceDeclaration { ns_name, value };
+            attributes.push(xml_attribute);
+        }
+
+        let s_tag = xml::STag { name, attributes };
+
+        s_tag.write(&mut self.inner).await?;
+
+        self.depth.push(element.name);
+        self.namespace_declarations
+            .push(element.namespace_declarations);
+        Ok(())
     }
 
-    pub async fn write_end(&mut self) -> Result<(), Error> {
-        let e_tag;
+    pub async fn write_end(&mut self) -> Result<()> {
         if let Some(name) = &self.depth.pop() {
+            let e_tag;
             let namespace_declarations_stack: Vec<_> =
                 self.namespace_declarations.iter().flatten().collect();
             let namespace_declaration = namespace_declarations_stack
@@ -65,25 +117,25 @@ impl<W: AsyncWrite, E: Into<Element>> Sink<E> for Writer<W> {
     fn poll_ready(
         self: std::pin::Pin<&mut Self>,
         cx: &mut std::task::Context<'_>,
-    ) -> std::task::Poll<Result<(), Self::Error>> {
+    ) -> std::task::Poll<Result<()>> {
         todo!()
     }
 
-    fn start_send(self: std::pin::Pin<&mut Self>, item: E) -> Result<(), Self::Error> {
+    fn start_send(self: std::pin::Pin<&mut Self>, item: E) -> Result<()> {
         todo!()
     }
 
     fn poll_flush(
         self: std::pin::Pin<&mut Self>,
         cx: &mut std::task::Context<'_>,
-    ) -> std::task::Poll<Result<(), Self::Error>> {
+    ) -> std::task::Poll<Result<()>> {
         todo!()
     }
 
     fn poll_close(
         self: std::pin::Pin<&mut Self>,
         cx: &mut std::task::Context<'_>,
-    ) -> std::task::Poll<Result<(), Self::Error>> {
+    ) -> std::task::Poll<Result<()>> {
         todo!()
     }
 }
diff --git a/src/xml/mod.rs b/src/xml/mod.rs
index 2d20ca0..8fb5419 100644
--- a/src/xml/mod.rs
+++ b/src/xml/mod.rs
@@ -1,4 +1,6 @@
-use std::{char, ops::Deref};
+use std::{char, convert::Infallible, ops::Deref, str::FromStr};
+
+use parsers_complete::Parser;
 
 use crate::error::Error;
 
@@ -228,14 +230,14 @@ pub enum EntityValue<'s> {
     SingleQuoted(Vec<EntityValueData<'s>>),
 }
 
-#[derive(Clone, Debug)]
+#[derive(Clone, Debug, PartialEq, Eq)]
 pub enum AttValueData<'s> {
     String(&'s str),
     Reference(Reference<'s>),
 }
 /// [10]   	AttValue	   ::=   	'"' ([^<&"] | Reference)* '"'
 /// 			|  "'" ([^<&'] | Reference)* "'"
-#[derive(Clone, Debug)]
+#[derive(Clone, Debug, PartialEq, Eq)]
 pub enum AttValue<'s> {
     DoubleQuoted(Vec<AttValueData<'s>>),
     SingleQuoted(Vec<AttValueData<'s>>),
@@ -259,6 +261,34 @@ impl<'s> AttValue<'s> {
     }
 }
 
+impl<'s> From<&'s str> for AttValue<'s> {
+    fn from(s: &'s str) -> AttValue<'s> {
+        let mut data = Vec::new();
+        for str in s.split_inclusive(|c| c == '<' || c == '"') {
+            if let Some(str) = str.strip_suffix('<') {
+                if !str.is_empty() {
+                    data.push(AttValueData::String(str))
+                }
+                data.push(AttValueData::Reference(Reference::EntityRef(EntityRef(
+                    Name::parse_full("lt").unwrap(),
+                ))))
+            } else if let Some(str) = str.strip_suffix('"') {
+                if !str.is_empty() {
+                    data.push(AttValueData::String(str))
+                }
+                data.push(AttValueData::Reference(Reference::EntityRef(EntityRef(
+                    Name::parse_full("quot").unwrap(),
+                ))))
+            } else {
+                if !str.is_empty() {
+                    data.push(AttValueData::String(str))
+                }
+            }
+        }
+        AttValue::DoubleQuoted(data)
+    }
+}
+
 /// [11]   	SystemLiteral	   ::=   	('"' [^"]* '"') | ("'" [^']* "'")
 #[derive(Debug)]
 pub enum SystemLiteral<'s> {
@@ -673,7 +703,7 @@ pub struct IgnoreSectContents<'s> {
 pub struct Ignore<'s>(&'s str);
 
 /// [66]   	CharRef	   ::=   	'&#' [0-9]+ ';' | '&#x' [0-9a-fA-F]+ ';'
-#[derive(Clone, Debug)]
+#[derive(Clone, Debug, PartialEq, Eq)]
 pub enum CharRef<'s> {
     Decimal(&'s str),
     Hexadecimal(&'s str),
@@ -706,7 +736,7 @@ impl<'s> CharRef<'s> {
 }
 
 /// [67]   	Reference	   ::=   	EntityRef | CharRef
-#[derive(Clone, Debug)]
+#[derive(Clone, Debug, PartialEq, Eq)]
 pub enum Reference<'s> {
     EntityRef(EntityRef<'s>),
     CharRef(CharRef<'s>),
@@ -729,8 +759,8 @@ impl<'s> Reference<'s> {
 }
 
 /// [68]   	EntityRef	   ::=   	'&' Name ';'
-#[derive(Clone, Debug)]
-pub struct EntityRef<'s>(Name<'s>);
+#[derive(Clone, Debug, PartialEq, Eq)]
+pub struct EntityRef<'s>(pub(crate) Name<'s>);
 
 impl<'s> Deref for EntityRef<'s> {
     type Target = Name<'s>;
@@ -835,3 +865,60 @@ pub struct NotationDecl<'s> {
 /// [83]   	PublicID	   ::=   	'PUBLIC' S PubidLiteral
 #[derive(Debug)]
 pub struct PublicID<'s>(PubidLiteral<'s>);
+
+#[cfg(test)]
+mod test {
+    use super::{AttValue, AttValueData, EntityRef, Name, Reference};
+
+    #[test]
+    fn att_value_from_str() {
+        assert_eq!(
+            AttValue::from("hsdaflaskdf<laksdf<abdsf"),
+            AttValue::DoubleQuoted(vec![
+                AttValueData::String("hsdaflaskdf"),
+                AttValueData::Reference(Reference::EntityRef(EntityRef(Name("lt")))),
+                AttValueData::String("laksdf"),
+                AttValueData::Reference(Reference::EntityRef(EntityRef(Name("lt")))),
+                AttValueData::String("abdsf"),
+            ])
+        );
+        assert_eq!(
+            AttValue::from("hsdaflaskdf<laksdf\"abdsf"),
+            AttValue::DoubleQuoted(vec![
+                AttValueData::String("hsdaflaskdf"),
+                AttValueData::Reference(Reference::EntityRef(EntityRef(Name("lt")))),
+                AttValueData::String("laksdf"),
+                AttValueData::Reference(Reference::EntityRef(EntityRef(Name("quot")))),
+                AttValueData::String("abdsf"),
+            ])
+        );
+        assert_eq!(
+            AttValue::from("hsdaflaskdf<laksdf\""),
+            AttValue::DoubleQuoted(vec![
+                AttValueData::String("hsdaflaskdf"),
+                AttValueData::Reference(Reference::EntityRef(EntityRef(Name("lt")))),
+                AttValueData::String("laksdf"),
+                AttValueData::Reference(Reference::EntityRef(EntityRef(Name("quot")))),
+            ])
+        );
+        assert_eq!(
+            AttValue::from("hsdaflaskdf\"<<laksdf\""),
+            AttValue::DoubleQuoted(vec![
+                AttValueData::String("hsdaflaskdf"),
+                AttValueData::Reference(Reference::EntityRef(EntityRef(Name("quot")))),
+                AttValueData::Reference(Reference::EntityRef(EntityRef(Name("lt")))),
+                AttValueData::Reference(Reference::EntityRef(EntityRef(Name("lt")))),
+                AttValueData::String("laksdf"),
+                AttValueData::Reference(Reference::EntityRef(EntityRef(Name("quot")))),
+            ])
+        );
+        assert_eq!(
+            AttValue::from("<<\""),
+            AttValue::DoubleQuoted(vec![
+                AttValueData::Reference(Reference::EntityRef(EntityRef(Name("lt")))),
+                AttValueData::Reference(Reference::EntityRef(EntityRef(Name("lt")))),
+                AttValueData::Reference(Reference::EntityRef(EntityRef(Name("quot")))),
+            ])
+        );
+    }
+}