Use three block form for the macro, fix some bugs, construct metadata tokens.

src/lib.rs

@@ -8,7 +8,7 @@ extern crate syn;
 
 use proc_macro::TokenStream;
 
-use quote::Tokens;
+use quote::{ToTokens, Tokens};
 use syn::{Expr, Field, Ident, Item};
 
 use parse::{Entry, parse_entries};
@@ -38,17 +38,26 @@ impl Api {
 
 impl From<Vec<Entry>> for Api {
     fn from(entries: Vec<Entry>) -> Api {
+        if entries.len() != 3 {
+            panic!("ruma_api! expects 3 blocks: metadata, request, and response");
+        }
+
+        let mut metadata = None;
+        let mut request = None;
+        let mut response = None;
+
+        for entry in entries {
+            match entry {
+                Entry::Metadata(fields) => metadata = Some(Metadata::from(fields)),
+                Entry::Request(fields) => request = Some(Request::from(fields)),
+                Entry::Response(fields) => response = Some(Response::from(fields)),
+            }
+        }
+
         Api {
-            metadata: Metadata {
+            metadata: metadata.expect("ruma_api! is missing metadata"),
-                description: Tokens::new(),
+            request: request.expect("ruma_api! is missing request"),
-                method: Tokens::new(),
+            response: response.expect("ruma_api! is missing response"),
-                name: Tokens::new(),
-                path: Tokens::new(),
-                rate_limited: Tokens::new(),
-                requires_authentication: Tokens::new(),
-            },
-            request: Request,
-            response: Response,
         }
     }
 }
@@ -62,20 +71,68 @@ struct Metadata {
     requires_authentication: Tokens,
 }
 
+impl From<Vec<(Ident, Expr)>> for Metadata {
+    fn from(fields: Vec<(Ident, Expr)>) -> Self {
+        let mut description = None;
+        let mut method = None;
+        let mut name = None;
+        let mut path = None;
+        let mut rate_limited = None;
+        let mut requires_authentication = None;
+
+        for field in fields {
+            let (identifier, expression) = field;
+
+            if identifier == Ident::new("description") {
+                description = Some(tokens_for(expression));
+            } else if identifier == Ident::new("method") {
+                method = Some(tokens_for(expression));
+            } else if identifier == Ident::new("name") {
+                name = Some(tokens_for(expression));
+            } else if identifier == Ident::new("path") {
+                path = Some(tokens_for(expression));
+            } else if identifier == Ident::new("rate_limited") {
+                rate_limited = Some(tokens_for(expression));
+            } else if identifier == Ident::new("requires_authentication") {
+                requires_authentication = Some(tokens_for(expression));
+            } else {
+                panic!("ruma_api! metadata included unexpected field: {}", identifier);
+            }
+        }
+
+        Metadata {
+            description: description.expect("ruma_api! metadata is missing description"),
+            method: method.expect("ruma_api! metadata is missing method"),
+            name: name.expect("ruma_api! metadata is missing name"),
+            path: path.expect("ruma_api! metadata is missing path"),
+            rate_limited: rate_limited.expect("ruma_api! metadata is missing rate_limited"),
+            requires_authentication: requires_authentication
+                .expect("ruma_api! metadata is missing requires_authentication"),
+        }
+    }
+}
+
 struct Request;
 
-impl From<Item> for Request {
+impl From<Vec<Field>> for Request {
-    fn from(item: Item) -> Self {
+    fn from(fields: Vec<Field>) -> Self {
         Request
-        // panic!("ruma_api! could not parse Request");
     }
 }
 
 struct Response;
 
-impl From<Item> for Response {
+impl From<Vec<Field>> for Response {
-    fn from(item: Item) -> Self {
+    fn from(fields: Vec<Field>) -> Self {
         Response
-        // panic!("ruma_api! could not parse Response");
     }
 }
+
+/// Helper method for turning a value into tokens.
+fn tokens_for<T>(value: T) -> Tokens where T: ToTokens {
+    let mut tokens = Tokens::new();
+
+    value.to_tokens(&mut tokens);
+
+    tokens
+}

src/parse.rs

@@ -16,6 +16,7 @@ use syn::{
 use syn::parse::{expr, ident, lit, ty};
 use synom::space::{block_comment, whitespace};
 
+#[derive(Debug)]
 pub enum Entry {
     Metadata(Vec<(Ident, Expr)>),
     Request(Vec<Field>),
@@ -30,25 +31,25 @@ named!(pub parse_entries -> Vec<Entry>, do_parse!(
 named!(entry -> Entry, alt!(
     do_parse!(
         keyword!("metadata") >>
-        punct!(":") >>
         punct!("{") >>
         fields: many0!(struct_init_field) >>
+        punct!("}") >>
         (Entry::Metadata(fields))
     )
     |
     do_parse!(
         keyword!("request") >>
-        punct!(":") >>
         punct!("{") >>
-        fields: many0!(struct_field) >>
+        fields: terminated_list!(punct!(","), struct_field) >>
+        punct!("}") >>
         (Entry::Request(fields))
     )
     |
     do_parse!(
         keyword!("response") >>
-        punct!(":") >>
         punct!("{") >>
-        fields: many0!(struct_field) >>
+        fields: terminated_list!(punct!(","), struct_field) >>
+        punct!("}") >>
         (Entry::Response(fields))
     )
 ));
@@ -63,14 +64,22 @@ named!(struct_init_field -> (Ident, Expr), do_parse!(
     (ident, expr)
 ));
 
+named!(pub struct_like_body -> Vec<Field>, do_parse!(
+    punct!("{") >>
+    fields: terminated_list!(punct!(","), struct_field) >>
+    punct!("}") >>
+    (fields)
+));
+
 named!(struct_field -> Field, do_parse!(
     attrs: many0!(outer_attr) >>
+    vis: visibility >>
     id: ident >>
     punct!(":") >>
     ty: ty >>
     (Field {
         ident: Some(id),
-        vis: Visibility::Public,
+        vis: Visibility::Public, // Ignore declared visibility, always make fields public
         attrs: attrs,
         ty: ty,
     })
@@ -142,3 +151,9 @@ named!(nested_meta_item -> NestedMetaItem, alt!(
     |
     lit => { NestedMetaItem::Literal }
 ));
+
+named!(visibility -> Visibility, alt!(
+    keyword!("pub") => { |_| Visibility::Public }
+    |
+    epsilon!() => { |_| Visibility::Inherited }
+));

tests/ruma_api_macros.rs

@@ -8,16 +8,18 @@ pub mod get_supported_versions {
     use ruma_api_macros::ruma_api;
 
     ruma_api! {
-        metadata: {
+        metadata {
             description: "Get the versions of the client-server API supported by this homeserver.",
             method: Method::Get,
             name: "api_versions",
             path: "/_matrix/client/versions",
             rate_limited: false,
             requires_authentication: true,
-        },
+        }
-        request: {},
+
-        response: {
+        request {}
+
+        response {
             /// A list of Matrix client API protocol versions supported by the homeserver.
             pub versions: Vec<String>,
         }