feat(neon-macros): Export Macro

crates/neon-macros/Cargo.toml

@@ -11,6 +11,6 @@ edition = "2021"
 proc-macro = true
 
 [dependencies]
+proc-macro2 = "1.0.79"
 quote = "1.0.33"
-syn = "2.0.39"
-syn-mid = "0.6.0"
+syn = { version = "2.0.57", features = ["full"] }

crates/neon-macros/src/export/function/meta.rs

@@ -0,0 +1,93 @@
+#[derive(Default)]
+pub(crate) struct Meta {
+    pub(super) kind: Kind,
+    pub(super) name: Option<syn::LitStr>,
+    pub(super) json: bool,
+    pub(super) context: bool,
+    pub(super) result: bool,
+}
+
+#[derive(Default)]
+pub(super) enum Kind {
+    #[default]
+    Normal,
+    Task,
+}
+
+impl Meta {
+    fn set_name(&mut self, meta: syn::meta::ParseNestedMeta) -> syn::Result<()> {
+        self.name = Some(meta.value()?.parse::<syn::LitStr>()?);
+
+        Ok(())
+    }
+
+    fn force_json(&mut self, _meta: syn::meta::ParseNestedMeta) -> syn::Result<()> {
+        self.json = true;
+
+        Ok(())
+    }
+
+    fn force_context(&mut self, meta: syn::meta::ParseNestedMeta) -> syn::Result<()> {
+        match self.kind {
+            Kind::Normal => {}
+            Kind::Task => return Err(meta.error(super::TASK_CX_ERROR)),
+        }
+
+        self.context = true;
+
+        Ok(())
+    }
+
+    fn force_result(&mut self, _meta: syn::meta::ParseNestedMeta) -> syn::Result<()> {
+        self.result = true;
+
+        Ok(())
+    }
+
+    fn make_task(&mut self, meta: syn::meta::ParseNestedMeta) -> syn::Result<()> {
+        if self.context {
+            return Err(meta.error(super::TASK_CX_ERROR));
+        }
+
+        self.kind = Kind::Task;
+
+        Ok(())
+    }
+}
+
+pub(crate) struct Parser;
+
+impl syn::parse::Parser for Parser {
+    type Output = Meta;
+
+    fn parse2(self, tokens: proc_macro2::TokenStream) -> syn::Result<Self::Output> {
+        let mut attr = Meta::default();
+        let parser = syn::meta::parser(|meta| {
+            if meta.path.is_ident("name") {
+                return attr.set_name(meta);
+            }
+
+            if meta.path.is_ident("json") {
+                return attr.force_json(meta);
+            }
+
+            if meta.path.is_ident("context") {
+                return attr.force_context(meta);
+            }
+
+            if meta.path.is_ident("result") {
+                return attr.force_result(meta);
+            }
+
+            if meta.path.is_ident("task") {
+                return attr.make_task(meta);
+            }
+
+            Err(meta.error("unsupported property"))
+        });
+
+        parser.parse2(tokens)?;
+
+        Ok(attr)
+    }
+}