feat: parse_inner_attrs

src/lib.rs

@@ -1,14 +1,34 @@
-pub fn add(left: usize, right: usize) -> usize {
-    left + right
-}
-
-#[cfg(test)]
-mod tests {
-    use super::*;
+#![no_std]
 
-    #[test]
-    fn it_works() {
-        let result = add(2, 2);
-        assert_eq!(result, 4);
-    }
+#[macro_export]
+macro_rules! parse_inner_attrs {
+    (
+        $([ $($before:tt)* ])?
+        {
+            $(#!$inner_attr:tt)+
+            $($rest:tt)*
+        }
+        $([ $($after:tt)* ])?
+        => $($out_macro_and_bang:tt)+
+    ) => {
+        $($out_macro_and_bang)+ {
+            $($($before)*)?
+            inner_attrs! { $(#!$inner_attr)+ }
+            rest! { $($rest)* }
+            $($($after)*)?
+        }
+    };
+    (
+        $([ $($before:tt)* ])?
+        { $($rest:tt)* }
+        $([ $($after:tt)* ])?
+        => $($out_macro_and_bang:tt)+
+    ) => {
+        $($out_macro_and_bang)+ {
+            $($($before)*)?
+            inner_attrs! {}
+            rest! { $($rest)* }
+            $($($after)*)?
+        }
+    };
 }

tests/inner_attrs.rs

@@ -0,0 +1,47 @@
+macro_rules! assert_no_inner_attrs {
+    (
+        inner_attrs! {}
+        rest! {}
+    ) => {};
+}
+
+syn_lite::parse_inner_attrs! {
+    {} => assert_no_inner_attrs!
+}
+
+#[test]
+fn full() {
+    let parsed;
+    let rest;
+    let before;
+    let after;
+
+    macro_rules! assert_no_inner_attrs {
+        (
+            before! { $($before:tt)* }
+            inner_attrs! {#![inner = $inner:literal]}
+            rest! { $($rest:tt)* }
+            after! { $($after:tt)* }
+        ) => {
+            $($before)*
+            parsed = $inner;
+            $($rest)*
+            $($after)*
+        };
+    }
+
+    syn_lite::parse_inner_attrs! {
+        [before! { before = true; }]
+        {
+            #![inner = true]
+            rest = true;
+        }
+        [after! { after = true; }]
+        => assert_no_inner_attrs!
+    }
+
+    assert!(parsed);
+    assert!(rest);
+    assert!(before);
+    assert!(after);
+}