feat(parser)!: fragments (#8)

stoically · stoically · commit da7d25b940ad · 2021-01-03T13:06:34.000+01:00
diff --git a/README.md b/README.md
@@ -58,11 +58,12 @@ assert_eq!(nodes[0].children[0].value_as_string().unwrap(), "hi");
   <div key=some::value() />
   ```
 
-- **Doctypes and Comments**
+- **Doctypes, Comments and Fragments**
 
   ```html
   <!DOCTYPE html>
   <!-- "comment" -->
+  <></>
   ```
 
 - **Braced blocks are parsed as arbitrary Rust code**
diff --git a/benches/bench.rs b/benches/bench.rs
@@ -4,7 +4,7 @@ use quote::quote;
 fn criterion_benchmark(c: &mut Criterion) {
     let tokens = quote! {
         <!DOCTYPE html>
-        <div>
+        <>
             <!-- "comment" -->
             <hello world />
             <div>"String literal"</div>
@@ -16,7 +16,7 @@ fn criterion_benchmark(c: &mut Criterion) {
             <div>{ let block = "in node position"; }</div>
             <div { let block = "in attribute position"; } />
             <div key={ let block = "in attribute value position"; } />
-        </div>
+        </>
     };
 
     c.bench_function("syn_rsx::parse2", |b| {
diff --git a/src/node.rs b/src/node.rs
@@ -102,6 +102,9 @@ pub enum NodeType {
     /// node value in this case
     Doctype,
 
+    /// Fragment: `<></>`
+    Fragment,
+
     /// Arbitrary rust code in braced `{}` blocks
     Block,
 }
@@ -117,6 +120,7 @@ impl fmt::Display for NodeType {
                 Self::Text => "NodeType::Text",
                 Self::Comment => "NodeType::Comment",
                 Self::Doctype => "NodeType::Doctype",
+                Self::Fragment => "NodeType::Fragment",
                 Self::Block => "NodeType::Block",
             }
         )
diff --git a/src/parser.rs b/src/parser.rs
@@ -137,6 +137,8 @@ impl Parser {
                 } else {
                     self.comment(input)
                 }
+            } else if input.peek2(Token![>]) {
+                self.fragment(input)
             } else {
                 self.element(input)
             }
@@ -446,6 +448,47 @@ impl Parser {
         })
     }
 
+    fn fragment(&self, input: ParseStream) -> Result<Node> {
+        self.fragment_open(input)?;
+
+        let mut children = vec![];
+        loop {
+            if input.is_empty() {
+                return Err(input.error("unexpected end of input"));
+            }
+
+            if let Ok(_) = self.fragment_close(&input.fork()) {
+                self.fragment_close(input)?;
+                break;
+            }
+
+            children.append(&mut self.node(input)?);
+        }
+
+        Ok(Node {
+            name: None,
+            value: None,
+            node_type: NodeType::Fragment,
+            attributes: vec![],
+            children,
+        })
+    }
+
+    fn fragment_open(&self, input: ParseStream) -> Result<()> {
+        input.parse::<Token![<]>()?;
+        input.parse::<Token![>]>()?;
+
+        Ok(())
+    }
+
+    fn fragment_close(&self, input: ParseStream) -> Result<()> {
+        input.parse::<Token![<]>()?;
+        input.parse::<Token![/]>()?;
+        input.parse::<Token![>]>()?;
+
+        Ok(())
+    }
+
     fn node_name(&self, input: ParseStream) -> Result<NodeName> {
         if input.peek2(Colon2) {
             self.node_name_punctuated_ident::<Colon2, fn(_) -> Colon2, PathSegment>(input, Colon2)
diff --git a/tests/test.rs b/tests/test.rs
@@ -227,3 +227,16 @@ fn test_comment() {
         Some("comment2".to_owned())
     );
 }
+
+#[test]
+fn test_fragment() {
+    let tokens = quote! {
+        <>
+            <div />
+        </>
+    };
+
+    let nodes = parse2(tokens);
+
+    assert!(nodes.is_ok());
+}

Original file line number	Diff line number	Diff line change
`@@ -102,6 +102,9 @@ pub enum NodeType {`
`102`	`102`	`/// node value in this case`
`103`	`103`	`Doctype,`
`104`	`104`
	`105`	+ /// Fragment: `<></>`
	`106`	`+ Fragment,`
	`107`	`+`
`105`	`108`	/// Arbitrary rust code in braced `{}` blocks
`106`	`109`	`Block,`
`107`	`110`	`}`
`@@ -117,6 +120,7 @@ impl fmt::Display for NodeType {`
`117`	`120`	`Self::Text => "NodeType::Text",`
`118`	`121`	`Self::Comment => "NodeType::Comment",`
`119`	`122`	`Self::Doctype => "NodeType::Doctype",`
	`123`	`+ Self::Fragment => "NodeType::Fragment",`
`120`	`124`	`Self::Block => "NodeType::Block",`
`121`	`125`	`}`
`122`	`126`	`)`