Create structure for citations.

src/parser/object.rs

@@ -19,6 +19,8 @@ pub enum Object<'s> {
     LatexFragment(LatexFragment<'s>),
     ExportSnippet(ExportSnippet<'s>),
     FootnoteReference(FootnoteReference<'s>),
+    Citation(Citation<'s>),
+    CitationReference(CitationReference<'s>),
 }
 
 #[derive(Debug, PartialEq)]
@@ -125,6 +127,16 @@ pub struct FootnoteReference<'s> {
     pub definition: Vec<Object<'s>>,
 }
 
+#[derive(Debug, PartialEq)]
+pub struct Citation<'s> {
+    pub source: &'s str,
+}
+
+#[derive(Debug, PartialEq)]
+pub struct CitationReference<'s> {
+    pub source: &'s str,
+}
+
 impl<'s> Source<'s> for Object<'s> {
     fn get_source(&'s self) -> &'s str {
         match self {
@@ -145,6 +157,8 @@ impl<'s> Source<'s> for Object<'s> {
             Object::LatexFragment(obj) => obj.source,
             Object::ExportSnippet(obj) => obj.source,
             Object::FootnoteReference(obj) => obj.source,
+            Object::Citation(obj) => obj.source,
+            Object::CitationReference(obj) => obj.source,
         }
     }
 }
@@ -244,3 +258,15 @@ impl<'s> Source<'s> for FootnoteReference<'s> {
         self.source
     }
 }
+
+impl<'s> Source<'s> for Citation<'s> {
+    fn get_source(&'s self) -> &'s str {
+        self.source
+    }
+}
+
+impl<'s> Source<'s> for CitationReference<'s> {
+    fn get_source(&'s self) -> &'s str {
+        self.source
+    }
+}