Release 0.9.4

Introduce ser::Impossible (fixes #694)

serde/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "serde"
-version = "0.9.2"
+version = "0.9.4"
 authors = ["Erick Tryzelaar <erick.tryzelaar@gmail.com>"]
 license = "MIT/Apache-2.0"
 description = "A generic serialization/deserialization framework"

serde/src/de/impls.rs

@@ -574,7 +574,7 @@ impl<T> Deserialize for [T; 0]
 }
 
 macro_rules! array_impls {
-    ($($len:expr => ($($name:ident)+))+) => {
+    ($($len:expr => ($($n:tt $name:ident)+))+) => {
         $(
             impl<T> Visitor for ArrayVisitor<[T; $len]> where T: Deserialize {
                 type Value = [T; $len];
@@ -590,7 +590,7 @@ macro_rules! array_impls {
                     $(
                         let $name = match try!(visitor.visit()) {
                             Some(val) => val,
-                            None => return Err(Error::invalid_length(0, &self)),
+                            None => return Err(Error::invalid_length($n, &self)),
                         };
                     )+
 
@@ -612,44 +612,44 @@ macro_rules! array_impls {
 }
 
 array_impls! {
-    1 => (a)
-    2 => (a b)
-    3 => (a b c)
-    4 => (a b c d)
-    5 => (a b c d e)
-    6 => (a b c d e f)
-    7 => (a b c d e f g)
-    8 => (a b c d e f g h)
-    9 => (a b c d e f g h i)
-    10 => (a b c d e f g h i j)
-    11 => (a b c d e f g h i j k)
-    12 => (a b c d e f g h i j k l)
-    13 => (a b c d e f g h i j k l m)
-    14 => (a b c d e f g h i j k l m n)
-    15 => (a b c d e f g h i j k l m n o)
-    16 => (a b c d e f g h i j k l m n o p)
-    17 => (a b c d e f g h i j k l m n o p q)
-    18 => (a b c d e f g h i j k l m n o p q r)
-    19 => (a b c d e f g h i j k l m n o p q r s)
-    20 => (a b c d e f g h i j k l m n o p q r s t)
-    21 => (a b c d e f g h i j k l m n o p q r s t u)
-    22 => (a b c d e f g h i j k l m n o p q r s t u v)
-    23 => (a b c d e f g h i j k l m n o p q r s t u v w)
-    24 => (a b c d e f g h i j k l m n o p q r s t u v w x)
-    25 => (a b c d e f g h i j k l m n o p q r s t u v w x y)
-    26 => (a b c d e f g h i j k l m n o p q r s t u v w x y z)
-    27 => (a b c d e f g h i j k l m n o p q r s t u v w x y z aa)
-    28 => (a b c d e f g h i j k l m n o p q r s t u v w x y z aa ab)
-    29 => (a b c d e f g h i j k l m n o p q r s t u v w x y z aa ab ac)
-    30 => (a b c d e f g h i j k l m n o p q r s t u v w x y z aa ab ac ad)
-    31 => (a b c d e f g h i j k l m n o p q r s t u v w x y z aa ab ac ad ae)
-    32 => (a b c d e f g h i j k l m n o p q r s t u v w x y z aa ab ac ad ae af)
+    1 => (0 a)
+    2 => (0 a 1 b)
+    3 => (0 a 1 b 2 c)
+    4 => (0 a 1 b 2 c 3 d)
+    5 => (0 a 1 b 2 c 3 d 4 e)
+    6 => (0 a 1 b 2 c 3 d 4 e 5 f)
+    7 => (0 a 1 b 2 c 3 d 4 e 5 f 6 g)
+    8 => (0 a 1 b 2 c 3 d 4 e 5 f 6 g 7 h)
+    9 => (0 a 1 b 2 c 3 d 4 e 5 f 6 g 7 h 8 i)
+    10 => (0 a 1 b 2 c 3 d 4 e 5 f 6 g 7 h 8 i 9 j)
+    11 => (0 a 1 b 2 c 3 d 4 e 5 f 6 g 7 h 8 i 9 j 10 k)
+    12 => (0 a 1 b 2 c 3 d 4 e 5 f 6 g 7 h 8 i 9 j 10 k 11 l)
+    13 => (0 a 1 b 2 c 3 d 4 e 5 f 6 g 7 h 8 i 9 j 10 k 11 l 12 m)
+    14 => (0 a 1 b 2 c 3 d 4 e 5 f 6 g 7 h 8 i 9 j 10 k 11 l 12 m 13 n)
+    15 => (0 a 1 b 2 c 3 d 4 e 5 f 6 g 7 h 8 i 9 j 10 k 11 l 12 m 13 n 14 o)
+    16 => (0 a 1 b 2 c 3 d 4 e 5 f 6 g 7 h 8 i 9 j 10 k 11 l 12 m 13 n 14 o 15 p)
+    17 => (0 a 1 b 2 c 3 d 4 e 5 f 6 g 7 h 8 i 9 j 10 k 11 l 12 m 13 n 14 o 15 p 16 q)
+    18 => (0 a 1 b 2 c 3 d 4 e 5 f 6 g 7 h 8 i 9 j 10 k 11 l 12 m 13 n 14 o 15 p 16 q 17 r)
+    19 => (0 a 1 b 2 c 3 d 4 e 5 f 6 g 7 h 8 i 9 j 10 k 11 l 12 m 13 n 14 o 15 p 16 q 17 r 18 s)
+    20 => (0 a 1 b 2 c 3 d 4 e 5 f 6 g 7 h 8 i 9 j 10 k 11 l 12 m 13 n 14 o 15 p 16 q 17 r 18 s 19 t)
+    21 => (0 a 1 b 2 c 3 d 4 e 5 f 6 g 7 h 8 i 9 j 10 k 11 l 12 m 13 n 14 o 15 p 16 q 17 r 18 s 19 t 20 u)
+    22 => (0 a 1 b 2 c 3 d 4 e 5 f 6 g 7 h 8 i 9 j 10 k 11 l 12 m 13 n 14 o 15 p 16 q 17 r 18 s 19 t 20 u 21 v)
+    23 => (0 a 1 b 2 c 3 d 4 e 5 f 6 g 7 h 8 i 9 j 10 k 11 l 12 m 13 n 14 o 15 p 16 q 17 r 18 s 19 t 20 u 21 v 22 w)
+    24 => (0 a 1 b 2 c 3 d 4 e 5 f 6 g 7 h 8 i 9 j 10 k 11 l 12 m 13 n 14 o 15 p 16 q 17 r 18 s 19 t 20 u 21 v 22 w 23 x)
+    25 => (0 a 1 b 2 c 3 d 4 e 5 f 6 g 7 h 8 i 9 j 10 k 11 l 12 m 13 n 14 o 15 p 16 q 17 r 18 s 19 t 20 u 21 v 22 w 23 x 24 y)
+    26 => (0 a 1 b 2 c 3 d 4 e 5 f 6 g 7 h 8 i 9 j 10 k 11 l 12 m 13 n 14 o 15 p 16 q 17 r 18 s 19 t 20 u 21 v 22 w 23 x 24 y 25 z)
+    27 => (0 a 1 b 2 c 3 d 4 e 5 f 6 g 7 h 8 i 9 j 10 k 11 l 12 m 13 n 14 o 15 p 16 q 17 r 18 s 19 t 20 u 21 v 22 w 23 x 24 y 25 z 26 aa)
+    28 => (0 a 1 b 2 c 3 d 4 e 5 f 6 g 7 h 8 i 9 j 10 k 11 l 12 m 13 n 14 o 15 p 16 q 17 r 18 s 19 t 20 u 21 v 22 w 23 x 24 y 25 z 26 aa 27 ab)
+    29 => (0 a 1 b 2 c 3 d 4 e 5 f 6 g 7 h 8 i 9 j 10 k 11 l 12 m 13 n 14 o 15 p 16 q 17 r 18 s 19 t 20 u 21 v 22 w 23 x 24 y 25 z 26 aa 27 ab 28 ac)
+    30 => (0 a 1 b 2 c 3 d 4 e 5 f 6 g 7 h 8 i 9 j 10 k 11 l 12 m 13 n 14 o 15 p 16 q 17 r 18 s 19 t 20 u 21 v 22 w 23 x 24 y 25 z 26 aa 27 ab 28 ac 29 ad)
+    31 => (0 a 1 b 2 c 3 d 4 e 5 f 6 g 7 h 8 i 9 j 10 k 11 l 12 m 13 n 14 o 15 p 16 q 17 r 18 s 19 t 20 u 21 v 22 w 23 x 24 y 25 z 26 aa 27 ab 28 ac 29 ad 30 ae)
+    32 => (0 a 1 b 2 c 3 d 4 e 5 f 6 g 7 h 8 i 9 j 10 k 11 l 12 m 13 n 14 o 15 p 16 q 17 r 18 s 19 t 20 u 21 v 22 w 23 x 24 y 25 z 26 aa 27 ab 28 ac 29 ad 30 ae 31 af)
 }
 
 ///////////////////////////////////////////////////////////////////////////////
 
 macro_rules! tuple_impls {
-    ($($len:expr => $visitor:ident => ($($name:ident)+))+) => {
+    ($($len:expr => $visitor:ident => ($($n:tt $name:ident)+))+) => {
         $(
             /// Construct a tuple visitor.
             pub struct $visitor<$($name,)+> {
@@ -678,7 +678,7 @@ macro_rules! tuple_impls {
                     $(
                         let $name = match try!(visitor.visit()) {
                             Some(value) => value,
-                            None => return Err(Error::invalid_length(0, &self)),
+                            None => return Err(Error::invalid_length($n, &self)),
                         };
                     )+
 
@@ -699,22 +699,22 @@ macro_rules! tuple_impls {
 }
 
 tuple_impls! {
-    1 => TupleVisitor1 => (T0)
-    2 => TupleVisitor2 => (T0 T1)
-    3 => TupleVisitor3 => (T0 T1 T2)
-    4 => TupleVisitor4 => (T0 T1 T2 T3)
-    5 => TupleVisitor5 => (T0 T1 T2 T3 T4)
-    6 => TupleVisitor6 => (T0 T1 T2 T3 T4 T5)
-    7 => TupleVisitor7 => (T0 T1 T2 T3 T4 T5 T6)
-    8 => TupleVisitor8 => (T0 T1 T2 T3 T4 T5 T6 T7)
-    9 => TupleVisitor9 => (T0 T1 T2 T3 T4 T5 T6 T7 T8)
-    10 => TupleVisitor10 => (T0 T1 T2 T3 T4 T5 T6 T7 T8 T9)
-    11 => TupleVisitor11 => (T0 T1 T2 T3 T4 T5 T6 T7 T8 T9 T10)
-    12 => TupleVisitor12 => (T0 T1 T2 T3 T4 T5 T6 T7 T8 T9 T10 T11)
-    13 => TupleVisitor13 => (T0 T1 T2 T3 T4 T5 T6 T7 T8 T9 T10 T11 T12)
-    14 => TupleVisitor14 => (T0 T1 T2 T3 T4 T5 T6 T7 T8 T9 T10 T11 T12 T13)
-    15 => TupleVisitor15 => (T0 T1 T2 T3 T4 T5 T6 T7 T8 T9 T10 T11 T12 T13 T14)
-    16 => TupleVisitor16 => (T0 T1 T2 T3 T4 T5 T6 T7 T8 T9 T10 T11 T12 T13 T14 T15)
+    1 => TupleVisitor1 => (0 T0)
+    2 => TupleVisitor2 => (0 T0 1 T1)
+    3 => TupleVisitor3 => (0 T0 1 T1 2 T2)
+    4 => TupleVisitor4 => (0 T0 1 T1 2 T2 3 T3)
+    5 => TupleVisitor5 => (0 T0 1 T1 2 T2 3 T3 4 T4)
+    6 => TupleVisitor6 => (0 T0 1 T1 2 T2 3 T3 4 T4 5 T5)
+    7 => TupleVisitor7 => (0 T0 1 T1 2 T2 3 T3 4 T4 5 T5 6 T6)
+    8 => TupleVisitor8 => (0 T0 1 T1 2 T2 3 T3 4 T4 5 T5 6 T6 7 T7)
+    9 => TupleVisitor9 => (0 T0 1 T1 2 T2 3 T3 4 T4 5 T5 6 T6 7 T7 8 T8)
+    10 => TupleVisitor10 => (0 T0 1 T1 2 T2 3 T3 4 T4 5 T5 6 T6 7 T7 8 T8 9 T9)
+    11 => TupleVisitor11 => (0 T0 1 T1 2 T2 3 T3 4 T4 5 T5 6 T6 7 T7 8 T8 9 T9 10 T10)
+    12 => TupleVisitor12 => (0 T0 1 T1 2 T2 3 T3 4 T4 5 T5 6 T6 7 T7 8 T8 9 T9 10 T10 11 T11)
+    13 => TupleVisitor13 => (0 T0 1 T1 2 T2 3 T3 4 T4 5 T5 6 T6 7 T7 8 T8 9 T9 10 T10 11 T11 12 T12)
+    14 => TupleVisitor14 => (0 T0 1 T1 2 T2 3 T3 4 T4 5 T5 6 T6 7 T7 8 T8 9 T9 10 T10 11 T11 12 T12 13 T13)
+    15 => TupleVisitor15 => (0 T0 1 T1 2 T2 3 T3 4 T4 5 T5 6 T6 7 T7 8 T8 9 T9 10 T10 11 T11 12 T12 13 T13 14 T14)
+    16 => TupleVisitor16 => (0 T0 1 T1 2 T2 3 T3 4 T4 5 T5 6 T6 7 T7 8 T8 9 T9 10 T10 11 T11 12 T12 13 T13 14 T14 15 T15)
 }
 
 ///////////////////////////////////////////////////////////////////////////////

serde/src/ser/impossible.rs

@@ -0,0 +1,177 @@
+//! This module contains `Impossible` serializer and its implementations.
+
+use core::marker::PhantomData;
+
+use ser::{
+    self,
+    Serialize,
+    SerializeSeq,
+    SerializeTuple,
+    SerializeTupleStruct,
+    SerializeTupleVariant,
+    SerializeMap,
+    SerializeStruct,
+    SerializeStructVariant,
+};
+
+/// Helper type for implementing a `Serializer` that does not support
+/// serializing one of the compound types.
+///
+/// This type cannot be instantiated, but implements every one of the traits
+/// corresponding to the `Serializer` compound types: `SerializeSeq`,
+/// `SerializeTuple`, `SerializeTupleStruct`, `SerializeTupleVariant`,
+/// `SerializeMap`, `SerializeStruct`, and `SerializeStructVariant`.
+///
+/// ```rust,ignore
+/// impl Serializer for MySerializer {
+///     type Ok = ();
+///     type Error = Error;
+///
+///     type SerializeSeq = Impossible<(), Error>;
+///     /* other associated types */
+///
+///     /// This data format does not support serializing sequences.
+///     fn serialize_seq(self,
+///                      len: Option<usize>)
+///                      -> Result<Self::SerializeSeq, Error> {
+///         // Given Impossible cannot be instantiated, the only
+///         // thing we can do here is to return an error.
+///         Err(...)
+///     }
+///
+///     /* other Serializer methods */
+/// }
+/// ```
+pub struct Impossible<Ok, E> {
+    void: Void,
+    _marker: PhantomData<(Ok, E)>,
+}
+
+enum Void {}
+
+impl<Ok, E> SerializeSeq for Impossible<Ok, E>
+    where E: ser::Error,
+{
+    type Ok = Ok;
+    type Error = E;
+
+    fn serialize_element<T: ?Sized + Serialize>(&mut self,
+                                                _value: &T)
+                                                -> Result<(), E> {
+        match self.void {}
+    }
+
+    fn end(self) -> Result<Ok, E> {
+        match self.void {}
+    }
+}
+
+impl<Ok, E> SerializeTuple for Impossible<Ok, E>
+    where E: ser::Error,
+{
+    type Ok = Ok;
+    type Error = E;
+
+    fn serialize_element<T: ?Sized + Serialize>(&mut self,
+                                                _value: &T)
+                                                -> Result<(), E> {
+        match self.void {}
+    }
+
+    fn end(self) -> Result<Ok, E> {
+        match self.void {}
+    }
+}
+
+impl<Ok, E> SerializeTupleStruct for Impossible<Ok, E>
+    where E: ser::Error,
+{
+    type Ok = Ok;
+    type Error = E;
+
+    fn serialize_field<T: ?Sized + Serialize>(&mut self,
+                                              _value: &T)
+                                              -> Result<(), E> {
+        match self.void {}
+    }
+
+    fn end(self) -> Result<Ok, E> {
+        match self.void {}
+    }
+}
+
+impl<Ok, E> SerializeTupleVariant for Impossible<Ok, E>
+    where E: ser::Error,
+{
+    type Ok = Ok;
+    type Error = E;
+
+    fn serialize_field<T: ?Sized + Serialize>(&mut self,
+                                              _value: &T)
+                                              -> Result<(), E> {
+        match self.void {}
+    }
+
+    fn end(self) -> Result<Ok, E> {
+        match self.void {}
+    }
+}
+
+impl<Ok, E> SerializeMap for Impossible<Ok, E>
+    where E: ser::Error,
+{
+    type Ok = Ok;
+    type Error = E;
+
+    fn serialize_key<T: ?Sized + Serialize>(&mut self,
+                                                 _key: &T)
+                                            -> Result<(), E> {
+        match self.void {}
+    }
+
+    fn serialize_value<T: ?Sized + Serialize>(&mut self,
+                                              _value: &T)
+                                              -> Result<(), E> {
+        match self.void {}
+    }
+
+    fn end(self) -> Result<Ok, E> {
+        match self.void {}
+    }
+}
+
+impl<Ok, E> SerializeStruct for Impossible<Ok, E>
+    where E: ser::Error,
+{
+    type Ok = Ok;
+    type Error = E;
+
+    fn serialize_field<T: ?Sized + Serialize>(&mut self,
+                                                   _key: &'static str,
+                                              _value: &T)
+                                              -> Result<(), E> {
+        match self.void {}
+    }
+
+    fn end(self) -> Result<Ok, E> {
+        match self.void {}
+    }
+}
+
+impl<Ok, E> SerializeStructVariant for Impossible<Ok, E>
+    where E: ser::Error,
+{
+    type Ok = Ok;
+    type Error = E;
+
+    fn serialize_field<T: ?Sized + Serialize>(&mut self,
+                                                   _key: &'static str,
+                                              _value: &T)
+                                              -> Result<(), E> {
+        match self.void {}
+    }
+
+    fn end(self) -> Result<Ok, E> {
+        match self.void {}
+    }
+}

serde/src/ser/mod.rs

@@ -104,6 +104,9 @@ use core::cell::RefCell;
 use core::fmt::Display;
 
 mod impls;
+mod impossible;
+
+pub use self::impossible::Impossible;
 
 ///////////////////////////////////////////////////////////////////////////////
 

serde_derive/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "serde_derive"
-version = "0.9.2"
+version = "0.9.4"
 authors = ["Erick Tryzelaar <erick.tryzelaar@gmail.com>"]
 license = "MIT/Apache-2.0"
 description = "Macros 1.1 implementation of #[derive(Serialize, Deserialize)]"

serde_test/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "serde_test"
-version = "0.9.2"
+version = "0.9.4"
 authors = ["Erick Tryzelaar <erick.tryzelaar@gmail.com>"]
 license = "MIT/Apache-2.0"
 description = "Token De/Serializer for testing De/Serialize implementations"

test_suite/tests/test_de.rs

@@ -97,7 +97,7 @@ macro_rules! declare_tests {
 }
 
 macro_rules! declare_error_tests {
-    ($($name:ident<$target:ident> { $tokens:expr, $expected:expr, })+) => {
+    ($($name:ident<$target:ty> { $tokens:expr, $expected:expr, })+) => {
         $(
             #[test]
             fn $name() {
@@ -936,4 +936,22 @@ declare_error_tests! {
         ],
         Error::Message("invalid value: integer `4`, expected variant index 0 <= i < 4".into()),
     }
+    test_short_tuple<(u8, u8, u8)> {
+        &[
+            Token::TupleStart(1),
+            Token::TupleSep,
+            Token::U8(1),
+            Token::TupleEnd,
+        ],
+        Error::Message("invalid length 1, expected a tuple of size 3".into()),
+    }
+    test_short_array<[u8; 3]> {
+        &[
+            Token::SeqStart(Some(1)),
+            Token::SeqSep,
+            Token::U8(1),
+            Token::SeqEnd,
+        ],
+        Error::Message("invalid length 1, expected an array of length 3".into()),
+    }
 }