From 2b9742b99e380483b154ce0bec307cc3abfd9d29 Mon Sep 17 00:00:00 2001
From: Jonas Platte <jplatte+git@posteo.de>
Date: Sat, 16 Nov 2019 14:06:02 +0100
Subject: [PATCH] Slightly simplify ruma_api! expansion code

---
 ruma-api-macros/src/api/request.rs  | 73 ++++++++++++++---------------
 ruma-api-macros/src/api/response.rs | 36 ++++++--------
 2 files changed, 48 insertions(+), 61 deletions(-)

diff --git a/ruma-api-macros/src/api/request.rs b/ruma-api-macros/src/api/request.rs
index e4862249..6e637200 100644
--- a/ruma-api-macros/src/api/request.rs
+++ b/ruma-api-macros/src/api/request.rs
@@ -194,14 +194,10 @@ impl ToTokens for Request {
         let request_struct_body = if self.fields.is_empty() {
             quote!(;)
         } else {
-            let fields = self.fields.iter().map(|request_field| {
-                let field = request_field.field();
-                let span = field.span();
-
-                let stripped_field = strip_serde_attrs(field);
-
-                quote_spanned!(span=> #stripped_field)
-            });
+            let fields = self
+                .fields
+                .iter()
+                .map(|request_field| strip_serde_attrs(request_field.field()));
 
             quote! {
                 {
@@ -221,16 +217,7 @@ impl ToTokens for Request {
                 struct RequestBody(#ty);
             }
         } else if self.has_body_fields() {
-            let fields = self
-                .fields
-                .iter()
-                .filter_map(|request_field| match *request_field {
-                    RequestField::Body(ref field) => {
-                        let span = field.span();
-                        Some(quote_spanned!(span=> #field))
-                    }
-                    _ => None,
-                });
+            let fields = self.fields.iter().filter_map(RequestField::as_body_field);
 
             quote! {
                 /// Data in the request body.
@@ -244,17 +231,7 @@ impl ToTokens for Request {
         };
 
         let request_path_struct = if self.has_path_fields() {
-            let fields = self
-                .fields
-                .iter()
-                .filter_map(|request_field| match *request_field {
-                    RequestField::Path(ref field) => {
-                        let span = field.span();
-
-                        Some(quote_spanned!(span=> #field))
-                    }
-                    _ => None,
-                });
+            let fields = self.fields.iter().filter_map(RequestField::as_path_field);
 
             quote! {
                 /// Data in the request path.
@@ -272,16 +249,7 @@ impl ToTokens for Request {
         };
 
         let request_query_struct = if self.has_query_fields() {
-            let fields = self
-                .fields
-                .iter()
-                .filter_map(|request_field| match *request_field {
-                    RequestField::Query(ref field) => {
-                        let span = field.span();
-                        Some(quote_spanned!(span=> #field))
-                    }
-                    _ => None,
-                });
+            let fields = self.fields.iter().filter_map(RequestField::as_query_field);
 
             quote! {
                 /// Data in the request's query string.
@@ -374,6 +342,33 @@ impl RequestField {
         self.kind() == RequestFieldKind::Query
     }
 
+    /// Return the contained field if this response field is a body kind.
+    fn as_body_field(&self) -> Option<&Field> {
+        if let RequestField::Body(field) = self {
+            Some(field)
+        } else {
+            None
+        }
+    }
+
+    /// Return the contained field if this response field is a path kind.
+    fn as_path_field(&self) -> Option<&Field> {
+        if let RequestField::Path(field) = self {
+            Some(field)
+        } else {
+            None
+        }
+    }
+
+    /// Return the contained field if this response field is a query kind.
+    fn as_query_field(&self) -> Option<&Field> {
+        if let RequestField::Query(field) = self {
+            Some(field)
+        } else {
+            None
+        }
+    }
+
     /// Gets the inner `Field` value.
     fn field(&self) -> &Field {
         match *self {
diff --git a/ruma-api-macros/src/api/response.rs b/ruma-api-macros/src/api/response.rs
index a5e3e632..e785a006 100644
--- a/ruma-api-macros/src/api/response.rs
+++ b/ruma-api-macros/src/api/response.rs
@@ -172,14 +172,10 @@ impl ToTokens for Response {
         let response_struct_body = if self.fields.is_empty() {
             quote!(;)
         } else {
-            let fields = self.fields.iter().map(|response_field| {
-                let field = response_field.field();
-                let span = field.span();
-
-                let stripped_field = strip_serde_attrs(field);
-
-                quote_spanned!(span=> #stripped_field)
-            });
+            let fields = self
+                .fields
+                .iter()
+                .map(|response_field| strip_serde_attrs(response_field.field()));
 
             quote! {
                 {
@@ -199,16 +195,7 @@ impl ToTokens for Response {
                 struct ResponseBody(#ty);
             }
         } else if self.has_body_fields() {
-            let fields = self
-                .fields
-                .iter()
-                .filter_map(|response_field| match *response_field {
-                    ResponseField::Body(ref field) => {
-                        let span = field.span();
-                        Some(quote_spanned!(span=> #field))
-                    }
-                    _ => None,
-                });
+            let fields = self.fields.iter().filter_map(ResponseField::as_body_field);
 
             quote! {
                 /// Data in the response body.
@@ -253,10 +240,7 @@ impl ResponseField {
 
     /// Whether or not this response field is a body kind.
     fn is_body(&self) -> bool {
-        match *self {
-            ResponseField::Body(_) => true,
-            _ => false,
-        }
+        self.as_body_field().is_some()
     }
 
     /// Whether or not this response field is a header kind.
@@ -267,6 +251,14 @@ impl ResponseField {
         }
     }
 
+    /// Return the contained field if this response field is a body kind.
+    fn as_body_field(&self) -> Option<&Field> {
+        match self {
+            ResponseField::Body(field) => Some(field),
+            _ => None,
+        }
+    }
+
     /// Whether or not this response field is a newtype body kind.
     fn is_newtype_body(&self) -> bool {
         match *self {