From b628446768a5c0eeba236253db89e92f4d7986f9 Mon Sep 17 00:00:00 2001
From: Erick Tryzelaar <erick.tryzelaar@gmail.com>
Date: Sun, 15 Mar 2015 15:04:11 -0700
Subject: [PATCH] Cleanup train

---
 serde_macros/src/de.rs    | 20 +++++---------------
 serde_macros/src/field.rs | 28 ++++++++++++++++++++++++++++
 serde_macros/src/ser.rs   | 21 +++------------------
 3 files changed, 36 insertions(+), 33 deletions(-)

diff --git a/serde_macros/src/de.rs b/serde_macros/src/de.rs
index 42a6a8c9..b69ed31f 100644
--- a/serde_macros/src/de.rs
+++ b/serde_macros/src/de.rs
@@ -34,7 +34,7 @@ use syntax::ptr::P;
 
 use aster;
 
-use field::field_alias;
+use field::struct_field_strs;
 
 pub fn expand_derive_deserialize(
     cx: &mut ExtCtxt,
@@ -431,7 +431,6 @@ fn deserialize_struct_named_fields(
         cx,
         builder,
         &field_names,
-        fields,
         struct_def,
     );
 
@@ -483,7 +482,6 @@ fn deserialize_field_visitor(
     cx: &ExtCtxt,
     builder: &aster::AstBuilder,
     field_names: &[ast::Ident],
-    fields: &[Ident],
     struct_def: &StructDef,
 ) -> Vec<P<ast::Item>> {
     let field_enum = builder.item().enum_("__Field")
@@ -495,20 +493,13 @@ fn deserialize_field_visitor(
         .build();
 
     // Get aliases
-    let aliases: Vec<Option<&ast::Lit>> = struct_def.fields.iter()
-        .map(field_alias)
-        .collect();
+    let aliases = struct_field_strs(cx, builder, struct_def);
 
     // Match arms to extract a field from a string
-    let field_arms: Vec<ast::Arm> = fields.iter()
+    let field_arms: Vec<ast::Arm> = aliases.iter()
         .zip(field_names.iter())
-        .zip(aliases.iter())
-        .map(|((name, field), alias_lit)| {
-            let s = match *alias_lit {
-                Some(lit) => builder.expr().build_lit(P(lit.clone())),
-                None => builder.expr().str(name),
-            };
-            quote_arm!(cx, $s => { Ok(__Field::$field) })
+        .map(|(alias, field)| {
+            quote_arm!(cx, $alias => { Ok(__Field::$field) })
         })
         .collect();
 
@@ -851,7 +842,6 @@ fn deserialize_enum_variant_map(
         cx,
         builder,
         &field_names,
-        fields,
         match variant.node.kind {
             ast::VariantKind::StructVariantKind(ref sd) => &*sd,
             _ => panic!("Mismatched enum types")
diff --git a/serde_macros/src/field.rs b/serde_macros/src/field.rs
index 6b9f8e83..dc0aeaee 100644
--- a/serde_macros/src/field.rs
+++ b/serde_macros/src/field.rs
@@ -1,4 +1,8 @@
 use syntax::ast;
+use syntax::ext::base::ExtCtxt;
+use syntax::ptr::P;
+
+use aster;
 
 pub fn field_alias(field: &ast::StructField) -> Option<&ast::Lit> {
     field.node.attrs.iter()
@@ -27,3 +31,27 @@ pub fn field_alias(field: &ast::StructField) -> Option<&ast::Lit> {
             }
         })
 }
+
+pub fn struct_field_strs(
+    cx: &ExtCtxt,
+    builder: &aster::AstBuilder,
+    struct_def: &ast::StructDef,
+) -> Vec<P<ast::Expr>> {
+    struct_def.fields.iter()
+        .map(|field| {
+            match field_alias(field) {
+                Some(alias) => builder.expr().build_lit(P(alias.clone())),
+                None => {
+                    match field.node.kind {
+                        ast::NamedField(name, _) => {
+                            builder.expr().str(name)
+                        }
+                        ast::UnnamedField(_) => {
+                            cx.bug("struct has named and unnamed fields")
+                        }
+                    }
+                }
+            }
+        })
+        .collect()
+}
diff --git a/serde_macros/src/ser.rs b/serde_macros/src/ser.rs
index 6681aaba..af1db63e 100644
--- a/serde_macros/src/ser.rs
+++ b/serde_macros/src/ser.rs
@@ -13,7 +13,7 @@ use syntax::ptr::P;
 
 use aster;
 
-use field::field_alias;
+use field::struct_field_strs;
 
 pub fn expand_derive_serialize(
     cx: &mut ExtCtxt,
@@ -520,24 +520,9 @@ fn serialize_struct_visitor<I>(
 {
     let len = struct_def.fields.len();
 
-    let key_exprs = struct_def.fields.iter()
-        .map(|field| {
-            match field_alias(field) {
-                Some(lit) => builder.expr().build_lit(P(lit.clone())),
-                None => {
-                    match field.node.kind {
-                        ast::NamedField(name, _) => {
-                            builder.expr().str(name)
-                        }
-                        ast::UnnamedField(_) => {
-                            cx.bug("struct has named and unnamed fields")
-                        }
-                    }
-                }
-            }
-        });
+    let key_exprs = struct_field_strs(cx, builder, struct_def);
 
-    let arms: Vec<ast::Arm> = key_exprs
+    let arms: Vec<ast::Arm> = key_exprs.iter()
         .zip(value_exprs)
         .enumerate()
         .map(|(i, (key_expr, value_expr))| {