Add implicit div class/id shorthand #172 (#173)

* Add implicit div class/id shorthand

* Add newline

* Add short explanation and example of implicit div

docs/content/basic-syntax.md

@@ -129,11 +129,11 @@ html! {
 
 ## Classes and IDs `.foo` `#bar`
 
-Add classes and IDs to an element using `.foo` and `#bar` syntax. You can chain multiple classes and IDs together, and mix and match them with other attributes:
+Add classes and IDs to an element using `.foo` and `#bar` syntax. The tag will default to `div` if an element begins with a class or ID. You can chain multiple classes and IDs together, and mix and match them with other attributes:
 
 ```rust
 html! {
-    div.container#main {
+    .container#main {
         input.big.scary.bright-red type="button" value="Launch Party Cannon";
     }
 }

maud/tests/basic_syntax.rs

@@ -201,3 +201,27 @@ fn classes_attrs_ids_mixed_up() {
     let s = html!(p { "Hi, " span.name.here lang="en" #thing { "Lyra" } "!" }).into_string();
     assert_eq!(s, r#"<p>Hi, <span class="name here" id="thing" lang="en">Lyra</span>!</p>"#);
 }
+
+#[test]
+fn div_shorthand_class() {
+    let s = html!(.awesome-class {}).into_string();
+    assert_eq!(s, r#"<div class="awesome-class"></div>"#);
+}
+
+#[test]
+fn div_shorthand_id() {
+    let s = html!(#unique-id {}).into_string();
+    assert_eq!(s, r#"<div id="unique-id"></div>"#);
+}
+
+#[test]
+fn div_shorthand_class_with_attrs() {
+    let s = html!(.awesome-class contenteditable? dir="rtl" #unique-id {}).into_string();
+    assert_eq!(s, r#"<div class="awesome-class" id="unique-id" contenteditable dir="rtl"></div>"#);
+}
+
+#[test]
+fn div_shorthand_id_with_attrs() {
+    let s = html!(#unique-id contenteditable? dir="rtl" .awesome-class {}).into_string();
+    assert_eq!(s, r#"<div class="awesome-class" id="unique-id" contenteditable dir="rtl"></div>"#);
+}

maud_macros/src/parse.rs

@@ -1,5 +1,6 @@
 use proc_macro::{
     Delimiter,
+    Ident,
     Literal,
     Spacing,
     Span,
@@ -164,6 +165,11 @@ impl Parser {
                 let name = self.try_namespaced_name().expect("identifier");
                 self.element(name)?
             },
+            // Div element shorthand
+            TokenTree::Punct(ref punct) if punct.as_char() == '.' || punct.as_char() == '#' => {
+                let name = TokenTree::Ident(Ident::new("div", punct.span()));
+                self.element(name.into())?
+            },
             // Splice
             TokenTree::Group(ref group) if group.delimiter() == Delimiter::Parenthesis => {
                 self.advance();