add two deserialization variations

This commit is contained in:
Erick Tryzelaar 2014-09-12 07:55:28 -07:00
parent 119bb0f590
commit 35786442f5
3 changed files with 430 additions and 0 deletions

94
serde2/src/de.rs Normal file
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@ -0,0 +1,94 @@
pub trait Deserialize<D, E> {
fn deserialize(state: &mut D) -> Result<Self, E>;
}
///////////////////////////////////////////////////////////////////////////////
pub trait Deserializer<D, R> {
fn deserialize<T: Deserialize<D, R>>(&mut self) -> R;
}
///////////////////////////////////////////////////////////////////////////////
pub trait Visitor<D, R> {
fn visit(&mut self, state: &mut S) -> Option<R>;
#[inline]
fn size_hint(&self) -> (uint, Option<uint>) {
(0, None)
}
}
pub trait SeqVisitor {
}
pub trait VisitorState<E> {
fn syntax_error
fn visit_int(&mut self) -> Result<int, E> {
}
fn visit_seq<Iter: FromIterator>(&mut self, ) -> Iter
}
///////////////////////////////////////////////////////////////////////////////
impl<D: VisitorState<E>, E> Deserialize<D, E> for int {
#[inline]
fn deserialize(state: &mut D) -> Result<int, E> {
state.visit_int()
}
}
impl<
T: Deserialize<D, E>,
D: VisitorState<E>,
E
> Deserialize<D, E> for Vec<T> {
#[inline]
fn deserialize(state: &mut D) -> Result<int, E> {
struct SeqVisitor {
}
impl SeqVisitor {
fn visit_seq<V: Visitor<Self>>(len: uint, visitor: V) {
let mut value = Vec::with_capacity(len);
loop {
match visitor.visit(self, &mut value) {
Some(()) => { }
None => { break; }
}
}
value
}
fn visit_seq_elt<
T: S
>(&mut self, value: &mut Vec<T>) {
let v = Deserialize
value.push(
}
}
let v = Vec::new();
state.visit_seq()
}
}

335
serde2/src/de2.rs Normal file
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@ -0,0 +1,335 @@
use std::collections::HashMap;
use std::hash::Hash;
///////////////////////////////////////////////////////////////////////////////
trait Deserialize<S, E> {
fn deserialize(state: &mut S) -> Result<Self, E>;
}
///////////////////////////////////////////////////////////////////////////////
trait VisitorState<E> {
fn visit_int(&mut self) -> Result<int, E>;
fn visit_string(&mut self) -> Result<String, E>;
fn visit_seq<
C: Deserialize<Self, E>,
V: Visitor<C, Self, E>
>(&mut self) -> Result<C, E>;
fn visit_map<
C: Deserialize<Self, E>,
V: Visitor<C, Self, E>
>(&mut self) -> Result<C, E>;
}
trait Visitor<C, S, E> {
fn new(len: uint) -> Self;
fn visit(&mut self, state: &mut S) -> Result<(), E>;
fn unwrap(self) -> Result<C, E>;
}
///////////////////////////////////////////////////////////////////////////////
impl<S: VisitorState<E>, E> Deserialize<S, E> for int {
fn deserialize(state: &mut S) -> Result<int, E> {
state.visit_int()
}
}
impl<S: VisitorState<E>, E> Deserialize<S, E> for String {
fn deserialize(state: &mut S) -> Result<String, E> {
state.visit_string()
}
}
///////////////////////////////////////////////////////////////////////////////
impl<
T: Deserialize<S, E>,
S: VisitorState<E>,
E
> Deserialize<S, E> for Vec<T> {
fn deserialize(state: &mut S) -> Result<Vec<T>, E> {
struct Visitor<T> {
value: Vec<T>,
}
impl<
T: Deserialize<S, E>,
S: VisitorState<E>,
E
> ::Visitor<Vec<T>, S, E> for Visitor<T> {
fn new(len: uint) -> Visitor<T> {
Visitor {
value: Vec::with_capacity(len),
}
}
fn visit(&mut self, state: &mut S) -> Result<(), E> {
let value = try!(Deserialize::deserialize(state));
self.value.push(value);
Ok(())
}
fn unwrap(self) -> Result<Vec<T>, E> {
Ok(self.value)
}
}
state.visit_seq::<Vec<T>, Visitor<T>>()
}
}
///////////////////////////////////////////////////////////////////////////////
impl<
T0: Deserialize<S, E>,
T1: Deserialize<S, E>,
S: VisitorState<E>,
E
> Deserialize<S, E> for (T0, T1) {
fn deserialize(state: &mut S) -> Result<(T0, T1), E> {
struct Visitor<T0, T1> {
state: uint,
t0: Option<T0>,
t1: Option<T1>,
}
impl<
T0: Deserialize<S, E>,
T1: Deserialize<S, E>,
S,
E
> ::Visitor<(T0, T1), S, E> for Visitor<T0, T1> {
fn new(_: uint) -> Visitor<T0, T1> {
Visitor {
state: 0,
t0: None,
t1: None,
}
}
fn visit(&mut self, state: &mut S) -> Result<(), E> {
match self.state {
0 => {
self.state += 1;
self.t0 = Some(try!(Deserialize::deserialize(state)));
}
1 => {
self.state += 1;
self.t1 = Some(try!(Deserialize::deserialize(state)));
}
_ => fail!()
}
Ok(())
}
fn unwrap(self) -> Result<(T0, T1), E> {
let t0 = match self.t0 {
Some(t0) => t0,
None => { fail!(); }
};
let t1 = match self.t1 {
Some(t1) => t1,
None => { fail!(); }
};
Ok((t0, t1))
}
}
state.visit_seq::<(T0, T1), Visitor<T0, T1>>()
}
}
///////////////////////////////////////////////////////////////////////////////
impl<
K: Deserialize<S, E> + Eq + Hash,
V: Deserialize<S, E>,
S: VisitorState<E>,
E
> Deserialize<S, E> for HashMap<K, V> {
fn deserialize(state: &mut S) -> Result<HashMap<K, V>, E> {
struct Visitor<K, V> {
value: HashMap<K, V>,
}
impl<
K: Deserialize<S, E> + Eq + Hash,
V: Deserialize<S, E>,
S: VisitorState<E>,
E
> ::Visitor<HashMap<K, V>, S, E> for Visitor<K, V> {
fn new(len: uint) -> Visitor<K, V> {
Visitor {
value: HashMap::with_capacity(len),
}
}
fn visit(&mut self, state: &mut S) -> Result<(), E> {
let key = try!(Deserialize::deserialize(state));
let value = try!(Deserialize::deserialize(state));
self.value.insert(key, value);
Ok(())
}
fn unwrap(self) -> Result<HashMap<K, V>, E> {
Ok(self.value)
}
}
state.visit_map::<HashMap<K, V>, Visitor<K, V>>()
}
}
///////////////////////////////////////////////////////////////////////////////
trait Deserializer<S, E> {
fn deserialize<T: Deserialize<S, E>>(&mut self) -> Result<T, E>;
}
///////////////////////////////////////////////////////////////////////////////
enum Token {
Int(int),
String(String),
SeqStart(uint),
MapStart(uint),
End,
}
struct MyDeserializerState<Iter> {
tokens: Iter,
peeked: Option<Token>,
}
impl<Iter: Iterator<Token>> MyDeserializerState<Iter> {
fn new(tokens: Iter) -> MyDeserializerState<Iter> {
MyDeserializerState {
tokens: tokens,
peeked: None,
}
}
fn next(&mut self) -> Option<Token> {
match self.peeked.take() {
Some(token) => { return Some(token); }
None => { }
}
self.tokens.next()
}
}
impl<Iter: Iterator<Token>> VisitorState<()> for MyDeserializerState<Iter> {
fn visit_int(&mut self) -> Result<int, ()> {
match self.next() {
Some(Int(v)) => Ok(v),
_ => Err(())
}
}
fn visit_string(&mut self) -> Result<String, ()> {
match self.next() {
Some(String(v)) => Ok(v),
_ => Err(())
}
}
fn visit_seq<
T: Deserialize<MyDeserializerState<Iter>, ()>,
V: Visitor<T, MyDeserializerState<Iter>, ()>
>(&mut self) -> Result<T, ()> {
let len = match self.next() {
Some(SeqStart(len)) => len,
_ => { return Err(()); }
};
let mut visitor: V = Visitor::new(len);
loop {
match self.next() {
Some(End) => { break; }
Some(token) => {
self.peeked = Some(token);
try!(visitor.visit(self));
}
_ => { return Err(()); }
}
}
visitor.unwrap()
}
fn visit_map<
T: Deserialize<MyDeserializerState<Iter>, ()>,
V: Visitor<T, MyDeserializerState<Iter>, ()>
>(&mut self) -> Result<T, ()> {
let len = match self.next() {
Some(MapStart(len)) => len,
_ => { return Err(()); }
};
let mut visitor: V = Visitor::new(len);
loop {
match self.next() {
Some(End) => { break; }
Some(token) => {
self.peeked = Some(token);
try!(visitor.visit(self));
}
_ => { return Err(()); }
}
}
visitor.unwrap()
}
}
///////////////////////////////////////////////////////////////////////////////
fn main() {
let tokens = vec!(
SeqStart(2),
Int(1),
Int(2),
End
);
let mut state = MyDeserializerState::new(tokens.move_iter());
let v: Result<Vec<int>, ()> = Deserialize::deserialize(&mut state);
println!("{}", v);
let tokens = vec!(
SeqStart(2),
Int(1),
Int(2),
End
);
let mut state = MyDeserializerState::new(tokens.move_iter());
let v: Result<(int, int), ()> = Deserialize::deserialize(&mut state);
println!("{}", v);
let tokens = vec!(
MapStart(2),
String("a".to_string()),
Int(1),
String("b".to_string()),
Int(2),
End
);
let mut state = MyDeserializerState::new(tokens.move_iter());
let v: Result<HashMap<String, int>, ()> = Deserialize::deserialize(&mut state);
println!("{}", v);
}

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@ -3,3 +3,4 @@ pub use self::ser::{to_vec, to_string};
pub use self::ser::escape_str;
pub mod ser;
pub mod de;