1 // Copyright 2012-2014 The Rust Project Developers. See the COPYRIGHT
2 // file at the top-level directory of this distribution and at
3 // http://rust-lang.org/COPYRIGHT.
5 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
6 // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
7 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
8 // option. This file may not be copied, modified, or distributed
9 // except according to those terms.
11 //! Support code for encoding and decoding types.
14 Core encoding and decoding interfaces.
20 pub trait Encoder<E> {
22 fn emit_nil(&mut self) -> Result<(), E>;
23 fn emit_uint(&mut self, v: uint) -> Result<(), E>;
24 fn emit_u64(&mut self, v: u64) -> Result<(), E>;
25 fn emit_u32(&mut self, v: u32) -> Result<(), E>;
26 fn emit_u16(&mut self, v: u16) -> Result<(), E>;
27 fn emit_u8(&mut self, v: u8) -> Result<(), E>;
28 fn emit_int(&mut self, v: int) -> Result<(), E>;
29 fn emit_i64(&mut self, v: i64) -> Result<(), E>;
30 fn emit_i32(&mut self, v: i32) -> Result<(), E>;
31 fn emit_i16(&mut self, v: i16) -> Result<(), E>;
32 fn emit_i8(&mut self, v: i8) -> Result<(), E>;
33 fn emit_bool(&mut self, v: bool) -> Result<(), E>;
34 fn emit_f64(&mut self, v: f64) -> Result<(), E>;
35 fn emit_f32(&mut self, v: f32) -> Result<(), E>;
36 fn emit_char(&mut self, v: char) -> Result<(), E>;
37 fn emit_str(&mut self, v: &str) -> Result<(), E>;
40 fn emit_enum(&mut self, name: &str, f: |&mut Self| -> Result<(), E>) -> Result<(), E>;
42 fn emit_enum_variant(&mut self,
46 f: |&mut Self| -> Result<(), E>) -> Result<(), E>;
47 fn emit_enum_variant_arg(&mut self,
49 f: |&mut Self| -> Result<(), E>) -> Result<(), E>;
51 fn emit_enum_struct_variant(&mut self,
55 f: |&mut Self| -> Result<(), E>) -> Result<(), E>;
56 fn emit_enum_struct_variant_field(&mut self,
59 f: |&mut Self| -> Result<(), E>) -> Result<(), E>;
61 fn emit_struct(&mut self,
64 f: |&mut Self| -> Result<(), E>) -> Result<(), E>;
65 fn emit_struct_field(&mut self,
68 f: |&mut Self| -> Result<(), E>) -> Result<(), E>;
70 fn emit_tuple(&mut self, len: uint, f: |&mut Self| -> Result<(), E>) -> Result<(), E>;
71 fn emit_tuple_arg(&mut self, idx: uint, f: |&mut Self| -> Result<(), E>) -> Result<(), E>;
73 fn emit_tuple_struct(&mut self,
76 f: |&mut Self| -> Result<(), E>) -> Result<(), E>;
77 fn emit_tuple_struct_arg(&mut self,
79 f: |&mut Self| -> Result<(), E>) -> Result<(), E>;
82 fn emit_option(&mut self, f: |&mut Self| -> Result<(), E>) -> Result<(), E>;
83 fn emit_option_none(&mut self) -> Result<(), E>;
84 fn emit_option_some(&mut self, f: |&mut Self| -> Result<(), E>) -> Result<(), E>;
86 fn emit_seq(&mut self, len: uint, f: |this: &mut Self| -> Result<(), E>) -> Result<(), E>;
87 fn emit_seq_elt(&mut self, idx: uint, f: |this: &mut Self| -> Result<(), E>) -> Result<(), E>;
89 fn emit_map(&mut self, len: uint, f: |&mut Self| -> Result<(), E>) -> Result<(), E>;
90 fn emit_map_elt_key(&mut self, idx: uint, f: |&mut Self| -> Result<(), E>) -> Result<(), E>;
91 fn emit_map_elt_val(&mut self, idx: uint, f: |&mut Self| -> Result<(), E>) -> Result<(), E>;
94 pub trait Decoder<E> {
96 fn read_nil(&mut self) -> Result<(), E>;
97 fn read_uint(&mut self) -> Result<uint, E>;
98 fn read_u64(&mut self) -> Result<u64, E>;
99 fn read_u32(&mut self) -> Result<u32, E>;
100 fn read_u16(&mut self) -> Result<u16, E>;
101 fn read_u8(&mut self) -> Result<u8, E>;
102 fn read_int(&mut self) -> Result<int, E>;
103 fn read_i64(&mut self) -> Result<i64, E>;
104 fn read_i32(&mut self) -> Result<i32, E>;
105 fn read_i16(&mut self) -> Result<i16, E>;
106 fn read_i8(&mut self) -> Result<i8, E>;
107 fn read_bool(&mut self) -> Result<bool, E>;
108 fn read_f64(&mut self) -> Result<f64, E>;
109 fn read_f32(&mut self) -> Result<f32, E>;
110 fn read_char(&mut self) -> Result<char, E>;
111 fn read_str(&mut self) -> Result<~str, E>;
114 fn read_enum<T>(&mut self, name: &str, f: |&mut Self| -> Result<T, E>) -> Result<T, E>;
116 fn read_enum_variant<T>(&mut self,
118 f: |&mut Self, uint| -> Result<T, E>)
120 fn read_enum_variant_arg<T>(&mut self,
122 f: |&mut Self| -> Result<T, E>)
125 fn read_enum_struct_variant<T>(&mut self,
127 f: |&mut Self, uint| -> Result<T, E>)
129 fn read_enum_struct_variant_field<T>(&mut self,
132 f: |&mut Self| -> Result<T, E>)
135 fn read_struct<T>(&mut self, s_name: &str, len: uint, f: |&mut Self| -> Result<T, E>)
137 fn read_struct_field<T>(&mut self,
140 f: |&mut Self| -> Result<T, E>)
143 fn read_tuple<T>(&mut self, f: |&mut Self, uint| -> Result<T, E>) -> Result<T, E>;
144 fn read_tuple_arg<T>(&mut self, a_idx: uint, f: |&mut Self| -> Result<T, E>) -> Result<T, E>;
146 fn read_tuple_struct<T>(&mut self,
148 f: |&mut Self, uint| -> Result<T, E>)
150 fn read_tuple_struct_arg<T>(&mut self,
152 f: |&mut Self| -> Result<T, E>)
155 // Specialized types:
156 fn read_option<T>(&mut self, f: |&mut Self, bool| -> Result<T, E>) -> Result<T, E>;
158 fn read_seq<T>(&mut self, f: |&mut Self, uint| -> Result<T, E>) -> Result<T, E>;
159 fn read_seq_elt<T>(&mut self, idx: uint, f: |&mut Self| -> Result<T, E>) -> Result<T, E>;
161 fn read_map<T>(&mut self, f: |&mut Self, uint| -> Result<T, E>) -> Result<T, E>;
162 fn read_map_elt_key<T>(&mut self, idx: uint, f: |&mut Self| -> Result<T, E>) -> Result<T, E>;
163 fn read_map_elt_val<T>(&mut self, idx: uint, f: |&mut Self| -> Result<T, E>) -> Result<T, E>;
166 pub trait Encodable<S:Encoder<E>, E> {
167 fn encode(&self, s: &mut S) -> Result<(), E>;
170 pub trait Decodable<D:Decoder<E>, E> {
171 fn decode(d: &mut D) -> Result<Self, E>;
174 macro_rules! try ( ($e:expr) => (
175 match $e { Ok(v) => v, Err(e) => return Err(e) }
178 impl<E, S:Encoder<E>> Encodable<S, E> for uint {
179 fn encode(&self, s: &mut S) -> Result<(), E> {
184 impl<E, D:Decoder<E>> Decodable<D, E> for uint {
185 fn decode(d: &mut D) -> Result<uint, E> {
190 impl<E, S:Encoder<E>> Encodable<S, E> for u8 {
191 fn encode(&self, s: &mut S) -> Result<(), E> {
196 impl<E, D:Decoder<E>> Decodable<D, E> for u8 {
197 fn decode(d: &mut D) -> Result<u8, E> {
202 impl<E, S:Encoder<E>> Encodable<S, E> for u16 {
203 fn encode(&self, s: &mut S) -> Result<(), E> {
208 impl<E, D:Decoder<E>> Decodable<D, E> for u16 {
209 fn decode(d: &mut D) -> Result<u16, E> {
214 impl<E, S:Encoder<E>> Encodable<S, E> for u32 {
215 fn encode(&self, s: &mut S) -> Result<(), E> {
220 impl<E, D:Decoder<E>> Decodable<D, E> for u32 {
221 fn decode(d: &mut D) -> Result<u32, E> {
226 impl<E, S:Encoder<E>> Encodable<S, E> for u64 {
227 fn encode(&self, s: &mut S) -> Result<(), E> {
232 impl<E, D:Decoder<E>> Decodable<D, E> for u64 {
233 fn decode(d: &mut D) -> Result<u64, E> {
238 impl<E, S:Encoder<E>> Encodable<S, E> for int {
239 fn encode(&self, s: &mut S) -> Result<(), E> {
244 impl<E, D:Decoder<E>> Decodable<D, E> for int {
245 fn decode(d: &mut D) -> Result<int, E> {
250 impl<E, S:Encoder<E>> Encodable<S, E> for i8 {
251 fn encode(&self, s: &mut S) -> Result<(), E> {
256 impl<E, D:Decoder<E>> Decodable<D, E> for i8 {
257 fn decode(d: &mut D) -> Result<i8, E> {
262 impl<E, S:Encoder<E>> Encodable<S, E> for i16 {
263 fn encode(&self, s: &mut S) -> Result<(), E> {
268 impl<E, D:Decoder<E>> Decodable<D, E> for i16 {
269 fn decode(d: &mut D) -> Result<i16, E> {
274 impl<E, S:Encoder<E>> Encodable<S, E> for i32 {
275 fn encode(&self, s: &mut S) -> Result<(), E> {
280 impl<E, D:Decoder<E>> Decodable<D, E> for i32 {
281 fn decode(d: &mut D) -> Result<i32, E> {
286 impl<E, S:Encoder<E>> Encodable<S, E> for i64 {
287 fn encode(&self, s: &mut S) -> Result<(), E> {
292 impl<E, D:Decoder<E>> Decodable<D, E> for i64 {
293 fn decode(d: &mut D) -> Result<i64, E> {
298 impl<'a, E, S:Encoder<E>> Encodable<S, E> for &'a str {
299 fn encode(&self, s: &mut S) -> Result<(), E> {
304 impl<E, S:Encoder<E>> Encodable<S, E> for ~str {
305 fn encode(&self, s: &mut S) -> Result<(), E> {
310 impl<E, D:Decoder<E>> Decodable<D, E> for ~str {
311 fn decode(d: &mut D) -> Result<~str, E> {
316 impl<E, S:Encoder<E>> Encodable<S, E> for StrBuf {
317 fn encode(&self, s: &mut S) -> Result<(), E> {
318 s.emit_str(self.as_slice())
322 impl<E, D:Decoder<E>> Decodable<D, E> for StrBuf {
323 fn decode(d: &mut D) -> Result<StrBuf, E> {
324 Ok(StrBuf::from_str(try!(d.read_str())))
328 impl<E, S:Encoder<E>> Encodable<S, E> for f32 {
329 fn encode(&self, s: &mut S) -> Result<(), E> {
334 impl<E, D:Decoder<E>> Decodable<D, E> for f32 {
335 fn decode(d: &mut D) -> Result<f32, E> {
340 impl<E, S:Encoder<E>> Encodable<S, E> for f64 {
341 fn encode(&self, s: &mut S) -> Result<(), E> {
346 impl<E, D:Decoder<E>> Decodable<D, E> for f64 {
347 fn decode(d: &mut D) -> Result<f64, E> {
352 impl<E, S:Encoder<E>> Encodable<S, E> for bool {
353 fn encode(&self, s: &mut S) -> Result<(), E> {
358 impl<E, D:Decoder<E>> Decodable<D, E> for bool {
359 fn decode(d: &mut D) -> Result<bool, E> {
364 impl<E, S:Encoder<E>> Encodable<S, E> for char {
365 fn encode(&self, s: &mut S) -> Result<(), E> {
370 impl<E, D:Decoder<E>> Decodable<D, E> for char {
371 fn decode(d: &mut D) -> Result<char, E> {
376 impl<E, S:Encoder<E>> Encodable<S, E> for () {
377 fn encode(&self, s: &mut S) -> Result<(), E> {
382 impl<E, D:Decoder<E>> Decodable<D, E> for () {
383 fn decode(d: &mut D) -> Result<(), E> {
388 impl<'a, E, S:Encoder<E>,T:Encodable<S, E>> Encodable<S, E> for &'a T {
389 fn encode(&self, s: &mut S) -> Result<(), E> {
394 impl<E, S:Encoder<E>,T:Encodable<S, E>> Encodable<S, E> for Box<T> {
395 fn encode(&self, s: &mut S) -> Result<(), E> {
400 impl<E, D:Decoder<E>,T:Decodable<D, E>> Decodable<D, E> for Box<T> {
401 fn decode(d: &mut D) -> Result<Box<T>, E> {
402 Ok(box try!(Decodable::decode(d)))
406 impl<E, S:Encoder<E>,T:Encodable<S, E>> Encodable<S, E> for @T {
407 fn encode(&self, s: &mut S) -> Result<(), E> {
412 impl<E, S:Encoder<E>,T:Encodable<S, E>> Encodable<S, E> for Rc<T> {
414 fn encode(&self, s: &mut S) -> Result<(), E> {
419 impl<E, D:Decoder<E>,T:Decodable<D, E>> Decodable<D, E> for Rc<T> {
421 fn decode(d: &mut D) -> Result<Rc<T>, E> {
422 Ok(Rc::new(try!(Decodable::decode(d))))
426 impl<E, D:Decoder<E>,T:Decodable<D, E> + 'static> Decodable<D, E> for @T {
427 fn decode(d: &mut D) -> Result<@T, E> {
428 Ok(@try!(Decodable::decode(d)))
432 impl<'a, E, S:Encoder<E>,T:Encodable<S, E>> Encodable<S, E> for &'a [T] {
433 fn encode(&self, s: &mut S) -> Result<(), E> {
434 s.emit_seq(self.len(), |s| {
435 for (i, e) in self.iter().enumerate() {
436 try!(s.emit_seq_elt(i, |s| e.encode(s)))
443 impl<E, S:Encoder<E>,T:Encodable<S, E>> Encodable<S, E> for ~[T] {
444 fn encode(&self, s: &mut S) -> Result<(), E> {
445 s.emit_seq(self.len(), |s| {
446 for (i, e) in self.iter().enumerate() {
447 try!(s.emit_seq_elt(i, |s| e.encode(s)))
454 impl<E, D:Decoder<E>,T:Decodable<D, E>> Decodable<D, E> for ~[T] {
455 fn decode(d: &mut D) -> Result<~[T], E> {
456 d.read_seq(|d, len| {
457 let mut v: Vec<T> = Vec::with_capacity(len);
458 for i in range(0, len) {
459 v.push(try!(d.read_seq_elt(i, |d| Decodable::decode(d))));
461 let k = v.move_iter().collect::<~[T]>();
467 impl<E, S:Encoder<E>,T:Encodable<S, E>> Encodable<S, E> for Vec<T> {
468 fn encode(&self, s: &mut S) -> Result<(), E> {
469 s.emit_seq(self.len(), |s| {
470 for (i, e) in self.iter().enumerate() {
471 try!(s.emit_seq_elt(i, |s| e.encode(s)))
478 impl<E, D:Decoder<E>,T:Decodable<D, E>> Decodable<D, E> for Vec<T> {
479 fn decode(d: &mut D) -> Result<Vec<T>, E> {
480 d.read_seq(|d, len| {
481 let mut v = Vec::with_capacity(len);
482 for i in range(0, len) {
483 v.push(try!(d.read_seq_elt(i, |d| Decodable::decode(d))));
490 impl<E, S:Encoder<E>,T:Encodable<S, E>> Encodable<S, E> for Option<T> {
491 fn encode(&self, s: &mut S) -> Result<(), E> {
494 None => s.emit_option_none(),
495 Some(ref v) => s.emit_option_some(|s| v.encode(s)),
501 impl<E, D:Decoder<E>,T:Decodable<D, E>> Decodable<D, E> for Option<T> {
502 fn decode(d: &mut D) -> Result<Option<T>, E> {
503 d.read_option(|d, b| {
505 Ok(Some(try!(Decodable::decode(d))))
513 macro_rules! peel(($name:ident, $($other:ident,)*) => (tuple!($($other,)*)))
517 ( $($name:ident,)+ ) => (
518 impl<E, D:Decoder<E>,$($name:Decodable<D, E>),*> Decodable<D,E> for ($($name,)*) {
519 #[allow(uppercase_variables)]
520 fn decode(d: &mut D) -> Result<($($name,)*), E> {
521 d.read_tuple(|d, amt| {
523 let ret = ($(try!(d.read_tuple_arg({ i+=1; i-1 }, |d| -> Result<$name,E> {
527 "expected tuple of length `{}`, found tuple \
528 of length `{}`", i, amt);
533 impl<E, S:Encoder<E>,$($name:Encodable<S, E>),*> Encodable<S, E> for ($($name,)*) {
534 #[allow(uppercase_variables)]
535 fn encode(&self, s: &mut S) -> Result<(), E> {
536 let ($(ref $name,)*) = *self;
538 $(let $name = $name; n += 1;)*
539 s.emit_tuple(n, |s| {
541 $(try!(s.emit_seq_elt({ i+=1; i-1 }, |s| $name.encode(s)));)*
550 tuple! { T0, T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, }
552 impl<E, S: Encoder<E>> Encodable<S, E> for path::posix::Path {
553 fn encode(&self, e: &mut S) -> Result<(), E> {
554 self.as_vec().encode(e)
558 impl<E, D: Decoder<E>> Decodable<D, E> for path::posix::Path {
559 fn decode(d: &mut D) -> Result<path::posix::Path, E> {
560 let bytes: ~[u8] = try!(Decodable::decode(d));
561 Ok(path::posix::Path::new(bytes))
565 impl<E, S: Encoder<E>> Encodable<S, E> for path::windows::Path {
566 fn encode(&self, e: &mut S) -> Result<(), E> {
567 self.as_vec().encode(e)
571 impl<E, D: Decoder<E>> Decodable<D, E> for path::windows::Path {
572 fn decode(d: &mut D) -> Result<path::windows::Path, E> {
573 let bytes: ~[u8] = try!(Decodable::decode(d));
574 Ok(path::windows::Path::new(bytes))
578 // ___________________________________________________________________________
581 // In some cases, these should eventually be coded as traits.
583 pub trait EncoderHelpers<E> {
584 fn emit_from_vec<T>(&mut self,
586 f: |&mut Self, v: &T| -> Result<(), E>) -> Result<(), E>;
589 impl<E, S:Encoder<E>> EncoderHelpers<E> for S {
590 fn emit_from_vec<T>(&mut self, v: &[T], f: |&mut S, &T| -> Result<(), E>) -> Result<(), E> {
591 self.emit_seq(v.len(), |this| {
592 for (i, e) in v.iter().enumerate() {
593 try!(this.emit_seq_elt(i, |this| {
602 pub trait DecoderHelpers<E> {
603 fn read_to_vec<T>(&mut self, f: |&mut Self| -> Result<T, E>) -> Result<~[T], E>;
606 impl<E, D:Decoder<E>> DecoderHelpers<E> for D {
607 fn read_to_vec<T>(&mut self, f: |&mut D| -> Result<T, E>) -> Result<~[T], E> {
608 self.read_seq(|this, len| {
609 let mut v = Vec::with_capacity(len);
610 for i in range(0, len) {
611 v.push(try!(this.read_seq_elt(i, |this| f(this))));
613 Ok(v.move_iter().collect())