From 499638eccdac849e82763b9dcee8351df9810f9b Mon Sep 17 00:00:00 2001
From: Erick Tryzelaar <erick.tryzelaar@gmail.com>
Date: Sun, 3 Aug 2014 12:34:57 -0700
Subject: [PATCH] simplify deserializing a value from a primitive

---
 src/bench_log.rs | 36 ++++++------------------------------
 src/de.rs        | 16 ++++++++++++++++
 2 files changed, 22 insertions(+), 30 deletions(-)

diff --git a/src/bench_log.rs b/src/bench_log.rs
index 58b18241..0b7ba6ae 100644
--- a/src/bench_log.rs
+++ b/src/bench_log.rs
@@ -51,11 +51,7 @@ impl de::Deserializable for HttpProtocol {
         D: de::Deserializer<E>,
         E
     >(d: &mut D, token: de::Token) -> Result<HttpProtocol, E> {
-        let x: uint = try!(de::Deserializable::deserialize_token(d, token));
-        match FromPrimitive::from_uint(x) {
-            Some(x) => Ok(x),
-            None => d.syntax_error(),
-        }
+        d.expect_from_primitive(token)
     }
 }
 
@@ -90,11 +86,7 @@ impl de::Deserializable for HttpMethod {
         D: de::Deserializer<E>,
         E
     >(d: &mut D, token: de::Token) -> Result<HttpMethod, E> {
-        let x: uint = try!(de::Deserializable::deserialize_token(d, token));
-        match FromPrimitive::from_uint(x) {
-            Some(x) => Ok(x),
-            None => d.syntax_error(),
-        }
+        d.expect_from_primitive(token)
     }
 }
 
@@ -122,11 +114,7 @@ impl de::Deserializable for CacheStatus {
         D: de::Deserializer<E>,
         E
     >(d: &mut D, token: de::Token) -> Result<CacheStatus, E> {
-        let x: uint = try!(de::Deserializable::deserialize_token(d, token));
-        match FromPrimitive::from_uint(x) {
-            Some(x) => Ok(x),
-            None => d.syntax_error(),
-        }
+        d.expect_from_primitive(token)
     }
 }
 
@@ -163,11 +151,7 @@ impl de::Deserializable for OriginProtocol {
         D: de::Deserializer<E>,
         E
     >(d: &mut D, token: de::Token) -> Result<OriginProtocol, E> {
-        let x: uint = try!(de::Deserializable::deserialize_token(d, token));
-        match FromPrimitive::from_uint(x) {
-            Some(x) => Ok(x),
-            None => d.syntax_error(),
-        }
+        d.expect_from_primitive(token)
     }
 }
 
@@ -196,11 +180,7 @@ impl de::Deserializable for ZonePlan {
         D: de::Deserializer<E>,
         E
     >(d: &mut D, token: de::Token) -> Result<ZonePlan, E> {
-        let x: uint = try!(de::Deserializable::deserialize_token(d, token));
-        match FromPrimitive::from_uint(x) {
-            Some(x) => Ok(x),
-            None => d.syntax_error(),
-        }
+        d.expect_from_primitive(token)
     }
 }
 
@@ -480,11 +460,7 @@ impl de::Deserializable for Country {
         D: de::Deserializer<E>,
         E
     >(d: &mut D, token: de::Token) -> Result<Country, E> {
-        let x: uint = try!(de::Deserializable::deserialize_token(d, token));
-        match FromPrimitive::from_uint(x) {
-            Some(x) => Ok(x),
-            None => d.syntax_error(),
-        }
+        d.expect_from_primitive(token)
     }
 }
 
diff --git a/src/de.rs b/src/de.rs
index 7ca6cbc3..e7ce7538 100644
--- a/src/de.rs
+++ b/src/de.rs
@@ -102,6 +102,22 @@ pub trait Deserializer<E>: Iterator<Result<Token, E>> {
             U64(x) => to_result!(num::cast(x), self.syntax_error()),
             F32(x) => to_result!(num::cast(x), self.syntax_error()),
             F64(x) => to_result!(num::cast(x), self.syntax_error()),
+
+    #[inline]
+    fn expect_from_primitive<T: FromPrimitive>(&mut self, token: Token) -> Result<T, E> {
+        match token {
+            Int(x) => to_result!(num::from_int(x), self.syntax_error()),
+            I8(x) => to_result!(num::from_i8(x), self.syntax_error()),
+            I16(x) => to_result!(num::from_i16(x), self.syntax_error()),
+            I32(x) => to_result!(num::from_i32(x), self.syntax_error()),
+            I64(x) => to_result!(num::from_i64(x), self.syntax_error()),
+            Uint(x) => to_result!(num::from_uint(x), self.syntax_error()),
+            U8(x) => to_result!(num::from_u8(x), self.syntax_error()),
+            U16(x) => to_result!(num::from_u16(x), self.syntax_error()),
+            U32(x) => to_result!(num::from_u32(x), self.syntax_error()),
+            U64(x) => to_result!(num::from_u64(x), self.syntax_error()),
+            F32(x) => to_result!(num::from_f32(x), self.syntax_error()),
+            F64(x) => to_result!(num::from_f64(x), self.syntax_error()),
             _ => self.syntax_error(),
         }
     }