blob: 2a3d087249b5ea7e5ab3ffa91c1a1272d54d0ba8 [file] [log] [blame]
// Copyright 2017 Serde Developers
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.
// Super explicit first paragraph because this shows up at the top level and
// trips up people who are just looking for basic Serialize / Deserialize
// documentation.
//
/// Helper macro when implementing the `Deserializer` part of a new data format
/// for Serde.
///
/// Some [`Deserializer`] implementations for self-describing formats do not
/// care what hint the [`Visitor`] gives them, they just want to blindly call
/// the [`Visitor`] method corresponding to the data they can tell is in the
/// input. This requires repetitive implementations of all the [`Deserializer`]
/// trait methods.
///
/// ```rust
/// # #[macro_use]
/// # extern crate serde;
/// #
/// # use serde::de::{value, Deserializer, Visitor};
/// #
/// # struct MyDeserializer;
/// #
/// # impl<'de> Deserializer<'de> for MyDeserializer {
/// # type Error = value::Error;
/// #
/// # fn deserialize_any<V>(self, _: V) -> Result<V::Value, Self::Error>
/// # where V: Visitor<'de>
/// # {
/// # unimplemented!()
/// # }
/// #
/// #[inline]
/// fn deserialize_bool<V>(self, visitor: V) -> Result<V::Value, Self::Error>
/// where V: Visitor<'de>
/// {
/// self.deserialize_any(visitor)
/// }
/// #
/// # forward_to_deserialize_any! {
/// # i8 i16 i32 i64 u8 u16 u32 u64 f32 f64 char str string bytes
/// # byte_buf option unit unit_struct newtype_struct seq tuple
/// # tuple_struct map struct enum identifier ignored_any
/// # }
/// # }
/// #
/// # fn main() {}
/// ```
///
/// The `forward_to_deserialize_any!` macro implements these simple forwarding
/// methods so that they forward directly to [`Deserializer::deserialize_any`].
/// You can choose which methods to forward.
///
/// ```rust
/// # #[macro_use]
/// # extern crate serde;
/// #
/// # use serde::de::{value, Deserializer, Visitor};
/// #
/// # struct MyDeserializer;
/// #
/// impl<'de> Deserializer<'de> for MyDeserializer {
/// # type Error = value::Error;
/// #
/// fn deserialize_any<V>(self, visitor: V) -> Result<V::Value, Self::Error>
/// where V: Visitor<'de>
/// {
/// /* ... */
/// # let _ = visitor;
/// # unimplemented!()
/// }
///
/// forward_to_deserialize_any! {
/// bool i8 i16 i32 i64 u8 u16 u32 u64 f32 f64 char str string bytes
/// byte_buf option unit unit_struct newtype_struct seq tuple
/// tuple_struct map struct enum identifier ignored_any
/// }
/// }
/// #
/// # fn main() {}
/// ```
///
/// The macro assumes the convention that your `Deserializer` lifetime parameter
/// is called `'de` and that the `Visitor` type parameters on each method are
/// called `V`. A different type parameter and a different lifetime can be
/// specified explicitly if necessary.
///
/// ```rust
/// # #[macro_use]
/// # extern crate serde;
/// #
/// # use std::marker::PhantomData;
/// #
/// # use serde::de::{value, Deserializer, Visitor};
/// #
/// # struct MyDeserializer<V>(PhantomData<V>);
/// #
/// # impl<'q, V> Deserializer<'q> for MyDeserializer<V> {
/// # type Error = value::Error;
/// #
/// # fn deserialize_any<W>(self, visitor: W) -> Result<W::Value, Self::Error>
/// # where W: Visitor<'q>
/// # {
/// # unimplemented!()
/// # }
/// #
/// forward_to_deserialize_any! {
/// <W: Visitor<'q>>
/// bool i8 i16 i32 i64 u8 u16 u32 u64 f32 f64 char str string bytes
/// byte_buf option unit unit_struct newtype_struct seq tuple tuple_struct
/// map struct enum identifier ignored_any
/// }
/// # }
/// #
/// # fn main() {}
/// ```
///
/// [`Deserializer`]: trait.Deserializer.html
/// [`Visitor`]: de/trait.Visitor.html
/// [`Deserializer::deserialize_any`]: trait.Deserializer.html#tymethod.deserialize_any
#[macro_export]
macro_rules! forward_to_deserialize_any {
(<$visitor:ident: Visitor<$lifetime:tt>> $($func:ident)*) => {
$(forward_to_deserialize_any_helper!{$func<$lifetime, $visitor>})*
};
// This case must be after the previous one.
($($func:ident)*) => {
$(forward_to_deserialize_any_helper!{$func<'de, V>})*
};
}
#[doc(hidden)]
#[macro_export]
macro_rules! forward_to_deserialize_any_method {
($func:ident<$l:tt, $v:ident>($($arg:ident : $ty:ty),*)) => {
#[inline]
fn $func<$v>(self, $($arg: $ty,)* visitor: $v) -> $crate::export::Result<$v::Value, Self::Error>
where
$v: $crate::de::Visitor<$l>,
{
$(
let _ = $arg;
)*
self.deserialize_any(visitor)
}
};
}
#[doc(hidden)]
#[macro_export]
macro_rules! forward_to_deserialize_any_helper {
(bool<$l:tt, $v:ident>) => {
forward_to_deserialize_any_method!{deserialize_bool<$l, $v>()}
};
(i8<$l:tt, $v:ident>) => {
forward_to_deserialize_any_method!{deserialize_i8<$l, $v>()}
};
(i16<$l:tt, $v:ident>) => {
forward_to_deserialize_any_method!{deserialize_i16<$l, $v>()}
};
(i32<$l:tt, $v:ident>) => {
forward_to_deserialize_any_method!{deserialize_i32<$l, $v>()}
};
(i64<$l:tt, $v:ident>) => {
forward_to_deserialize_any_method!{deserialize_i64<$l, $v>()}
};
(u8<$l:tt, $v:ident>) => {
forward_to_deserialize_any_method!{deserialize_u8<$l, $v>()}
};
(u16<$l:tt, $v:ident>) => {
forward_to_deserialize_any_method!{deserialize_u16<$l, $v>()}
};
(u32<$l:tt, $v:ident>) => {
forward_to_deserialize_any_method!{deserialize_u32<$l, $v>()}
};
(u64<$l:tt, $v:ident>) => {
forward_to_deserialize_any_method!{deserialize_u64<$l, $v>()}
};
(f32<$l:tt, $v:ident>) => {
forward_to_deserialize_any_method!{deserialize_f32<$l, $v>()}
};
(f64<$l:tt, $v:ident>) => {
forward_to_deserialize_any_method!{deserialize_f64<$l, $v>()}
};
(char<$l:tt, $v:ident>) => {
forward_to_deserialize_any_method!{deserialize_char<$l, $v>()}
};
(str<$l:tt, $v:ident>) => {
forward_to_deserialize_any_method!{deserialize_str<$l, $v>()}
};
(string<$l:tt, $v:ident>) => {
forward_to_deserialize_any_method!{deserialize_string<$l, $v>()}
};
(bytes<$l:tt, $v:ident>) => {
forward_to_deserialize_any_method!{deserialize_bytes<$l, $v>()}
};
(byte_buf<$l:tt, $v:ident>) => {
forward_to_deserialize_any_method!{deserialize_byte_buf<$l, $v>()}
};
(option<$l:tt, $v:ident>) => {
forward_to_deserialize_any_method!{deserialize_option<$l, $v>()}
};
(unit<$l:tt, $v:ident>) => {
forward_to_deserialize_any_method!{deserialize_unit<$l, $v>()}
};
(unit_struct<$l:tt, $v:ident>) => {
forward_to_deserialize_any_method!{deserialize_unit_struct<$l, $v>(name: &'static str)}
};
(newtype_struct<$l:tt, $v:ident>) => {
forward_to_deserialize_any_method!{deserialize_newtype_struct<$l, $v>(name: &'static str)}
};
(seq<$l:tt, $v:ident>) => {
forward_to_deserialize_any_method!{deserialize_seq<$l, $v>()}
};
(tuple<$l:tt, $v:ident>) => {
forward_to_deserialize_any_method!{deserialize_tuple<$l, $v>(len: usize)}
};
(tuple_struct<$l:tt, $v:ident>) => {
forward_to_deserialize_any_method!{deserialize_tuple_struct<$l, $v>(name: &'static str, len: usize)}
};
(map<$l:tt, $v:ident>) => {
forward_to_deserialize_any_method!{deserialize_map<$l, $v>()}
};
(struct<$l:tt, $v:ident>) => {
forward_to_deserialize_any_method!{deserialize_struct<$l, $v>(name: &'static str, fields: &'static [&'static str])}
};
(enum<$l:tt, $v:ident>) => {
forward_to_deserialize_any_method!{deserialize_enum<$l, $v>(name: &'static str, variants: &'static [&'static str])}
};
(identifier<$l:tt, $v:ident>) => {
forward_to_deserialize_any_method!{deserialize_identifier<$l, $v>()}
};
(ignored_any<$l:tt, $v:ident>) => {
forward_to_deserialize_any_method!{deserialize_ignored_any<$l, $v>()}
};
}