rust/src/libstd/json.rs
2013-03-30 13:31:03 -07:00

1773 lines
51 KiB
Rust

// Copyright 2012 The Rust Project Developers. See the COPYRIGHT
// file at the top-level directory of this distribution and at
// http://rust-lang.org/COPYRIGHT.
//
// 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.
// Rust JSON serialization library
// Copyright (c) 2011 Google Inc.
#[forbid(non_camel_case_types)];
//! json serialization
use core::prelude::*;
use core::io::{WriterUtil, ReaderUtil};
use core::hashmap::linear::LinearMap;
use serialize::Encodable;
use serialize;
use sort::Sort;
/// Represents a json value
pub enum Json {
Number(float),
String(~str),
Boolean(bool),
List(List),
Object(~Object),
Null,
}
pub type List = ~[Json];
pub type Object = LinearMap<~str, Json>;
#[deriving(Eq)]
pub struct Error {
line: uint,
col: uint,
msg: @~str,
}
fn escape_str(s: &str) -> ~str {
let mut escaped = ~"\"";
for str::each_char(s) |c| {
match c {
'"' => escaped += ~"\\\"",
'\\' => escaped += ~"\\\\",
'\x08' => escaped += ~"\\b",
'\x0c' => escaped += ~"\\f",
'\n' => escaped += ~"\\n",
'\r' => escaped += ~"\\r",
'\t' => escaped += ~"\\t",
_ => escaped += str::from_char(c)
}
};
escaped += ~"\"";
escaped
}
fn spaces(n: uint) -> ~str {
let mut ss = ~"";
for n.times { str::push_str(&mut ss, " "); }
return ss;
}
pub struct Encoder {
priv wr: @io::Writer,
}
pub fn Encoder(wr: @io::Writer) -> Encoder {
Encoder { wr: wr }
}
impl serialize::Encoder for Encoder {
fn emit_nil(&self) { self.wr.write_str("null") }
fn emit_uint(&self, v: uint) { self.emit_float(v as float); }
fn emit_u64(&self, v: u64) { self.emit_float(v as float); }
fn emit_u32(&self, v: u32) { self.emit_float(v as float); }
fn emit_u16(&self, v: u16) { self.emit_float(v as float); }
fn emit_u8(&self, v: u8) { self.emit_float(v as float); }
fn emit_int(&self, v: int) { self.emit_float(v as float); }
fn emit_i64(&self, v: i64) { self.emit_float(v as float); }
fn emit_i32(&self, v: i32) { self.emit_float(v as float); }
fn emit_i16(&self, v: i16) { self.emit_float(v as float); }
fn emit_i8(&self, v: i8) { self.emit_float(v as float); }
fn emit_bool(&self, v: bool) {
if v {
self.wr.write_str("true");
} else {
self.wr.write_str("false");
}
}
fn emit_f64(&self, v: f64) { self.emit_float(v as float); }
fn emit_f32(&self, v: f32) { self.emit_float(v as float); }
fn emit_float(&self, v: float) {
self.wr.write_str(float::to_str_digits(v, 6u));
}
fn emit_char(&self, v: char) { self.emit_str(str::from_char(v)) }
fn emit_str(&self, v: &str) { self.wr.write_str(escape_str(v)) }
fn emit_enum(&self, _name: &str, f: &fn()) { f() }
fn emit_enum_variant(&self, name: &str, _id: uint, cnt: uint, f: &fn()) {
// enums are encoded as strings or vectors:
// Bunny => "Bunny"
// Kangaroo(34,"William") => ["Kangaroo",[34,"William"]]
if cnt == 0 {
self.wr.write_str(escape_str(name));
} else {
self.wr.write_char('[');
self.wr.write_str(escape_str(name));
self.wr.write_char(',');
f();
self.wr.write_char(']');
}
}
fn emit_enum_variant_arg(&self, idx: uint, f: &fn()) {
if (idx != 0) {self.wr.write_char(',');}
f();
}
fn emit_seq(&self, _len: uint, f: &fn()) {
self.wr.write_char('[');
f();
self.wr.write_char(']');
}
fn emit_seq_elt(&self, idx: uint, f: &fn()) {
if idx != 0 { self.wr.write_char(','); }
f()
}
fn emit_struct(&self, _name: &str, _len: uint, f: &fn()) {
self.wr.write_char('{');
f();
self.wr.write_char('}');
}
fn emit_field(&self, name: &str, idx: uint, f: &fn()) {
if idx != 0 { self.wr.write_char(','); }
self.wr.write_str(escape_str(name));
self.wr.write_char(':');
f();
}
fn emit_option(&self, f: &fn()) { f(); }
fn emit_option_none(&self) { self.emit_nil(); }
fn emit_option_some(&self, f: &fn()) { f(); }
fn emit_map(&self, _len: uint, f: &fn()) {
self.wr.write_char('{');
f();
self.wr.write_char('}');
}
fn emit_map_elt_key(&self, idx: uint, f: &fn()) {
if idx != 0 { self.wr.write_char(','); }
f()
}
fn emit_map_elt_val(&self, _idx: uint, f: &fn()) {
self.wr.write_char(':');
f()
}
}
pub struct PrettyEncoder {
priv wr: @io::Writer,
priv mut indent: uint,
}
pub fn PrettyEncoder(wr: @io::Writer) -> PrettyEncoder {
PrettyEncoder { wr: wr, indent: 0 }
}
impl serialize::Encoder for PrettyEncoder {
fn emit_nil(&self) { self.wr.write_str("null") }
fn emit_uint(&self, v: uint) { self.emit_float(v as float); }
fn emit_u64(&self, v: u64) { self.emit_float(v as float); }
fn emit_u32(&self, v: u32) { self.emit_float(v as float); }
fn emit_u16(&self, v: u16) { self.emit_float(v as float); }
fn emit_u8(&self, v: u8) { self.emit_float(v as float); }
fn emit_int(&self, v: int) { self.emit_float(v as float); }
fn emit_i64(&self, v: i64) { self.emit_float(v as float); }
fn emit_i32(&self, v: i32) { self.emit_float(v as float); }
fn emit_i16(&self, v: i16) { self.emit_float(v as float); }
fn emit_i8(&self, v: i8) { self.emit_float(v as float); }
fn emit_bool(&self, v: bool) {
if v {
self.wr.write_str("true");
} else {
self.wr.write_str("false");
}
}
fn emit_f64(&self, v: f64) { self.emit_float(v as float); }
fn emit_f32(&self, v: f32) { self.emit_float(v as float); }
fn emit_float(&self, v: float) {
self.wr.write_str(float::to_str_digits(v, 6u));
}
fn emit_char(&self, v: char) { self.emit_str(str::from_char(v)) }
fn emit_str(&self, v: &str) { self.wr.write_str(escape_str(v)); }
fn emit_enum(&self, _name: &str, f: &fn()) { f() }
fn emit_enum_variant(&self, name: &str, _id: uint, cnt: uint, f: &fn()) {
if cnt == 0 {
self.wr.write_str(escape_str(name));
} else {
self.wr.write_char('[');
self.indent += 2;
self.wr.write_char('\n');
self.wr.write_str(spaces(self.indent));
self.wr.write_str(escape_str(name));
self.wr.write_str(",\n");
f();
self.wr.write_char('\n');
self.indent -= 2;
self.wr.write_str(spaces(self.indent));
self.wr.write_char(']');
}
}
fn emit_enum_variant_arg(&self, idx: uint, f: &fn()) {
if idx != 0 {
self.wr.write_str(",\n");
}
self.wr.write_str(spaces(self.indent));
f()
}
fn emit_seq(&self, len: uint, f: &fn()) {
if len == 0 {
self.wr.write_str("[]");
} else {
self.wr.write_char('[');
self.indent += 2;
f();
self.wr.write_char('\n');
self.indent -= 2;
self.wr.write_str(spaces(self.indent));
self.wr.write_char(']');
}
}
fn emit_seq_elt(&self, idx: uint, f: &fn()) {
if idx == 0 {
self.wr.write_char('\n');
} else {
self.wr.write_str(",\n");
}
self.wr.write_str(spaces(self.indent));
f()
}
fn emit_struct(&self, _name: &str, len: uint, f: &fn()) {
if len == 0 {
self.wr.write_str("{}");
} else {
self.wr.write_char('{');
self.indent += 2;
f();
self.wr.write_char('\n');
self.indent -= 2;
self.wr.write_str(spaces(self.indent));
self.wr.write_char('}');
}
}
fn emit_field(&self, name: &str, idx: uint, f: &fn()) {
if idx == 0 {
self.wr.write_char('\n');
} else {
self.wr.write_str(",\n");
}
self.wr.write_str(spaces(self.indent));
self.wr.write_str(escape_str(name));
self.wr.write_str(": ");
f();
}
fn emit_option(&self, f: &fn()) { f(); }
fn emit_option_none(&self) { self.emit_nil(); }
fn emit_option_some(&self, f: &fn()) { f(); }
fn emit_map(&self, len: uint, f: &fn()) {
if len == 0 {
self.wr.write_str("{}");
} else {
self.wr.write_char('{');
self.indent += 2;
f();
self.wr.write_char('\n');
self.indent -= 2;
self.wr.write_str(spaces(self.indent));
self.wr.write_char('}');
}
}
fn emit_map_elt_key(&self, idx: uint, f: &fn()) {
if idx == 0 {
self.wr.write_char('\n');
} else {
self.wr.write_str(",\n");
}
self.wr.write_str(spaces(self.indent));
f();
}
fn emit_map_elt_val(&self, _idx: uint, f: &fn()) {
self.wr.write_str(": ");
f();
}
}
impl<E: serialize::Encoder> serialize::Encodable<E> for Json {
fn encode(&self, e: &E) {
match *self {
Number(v) => v.encode(e),
String(ref v) => v.encode(e),
Boolean(v) => v.encode(e),
List(ref v) => v.encode(e),
Object(ref v) => v.encode(e),
Null => e.emit_nil(),
}
}
}
/// Encodes a json value into a io::writer
pub fn to_writer(wr: @io::Writer, json: &Json) {
json.encode(&Encoder(wr))
}
/// Encodes a json value into a string
pub fn to_str(json: &Json) -> ~str {
unsafe {
// ugh, should be safe
io::with_str_writer(|wr| to_writer(wr, json))
}
}
/// Encodes a json value into a io::writer
pub fn to_pretty_writer(wr: @io::Writer, json: &Json) {
json.encode(&PrettyEncoder(wr))
}
/// Encodes a json value into a string
pub fn to_pretty_str(json: &Json) -> ~str {
io::with_str_writer(|wr| to_pretty_writer(wr, json))
}
pub struct Parser {
priv rdr: @io::Reader,
priv mut ch: char,
priv mut line: uint,
priv mut col: uint,
}
/// Decode a json value from an io::reader
pub fn Parser(rdr: @io::Reader) -> Parser {
Parser {
rdr: rdr,
ch: rdr.read_char(),
line: 1,
col: 1,
}
}
pub impl Parser {
fn parse(&self) -> Result<Json, Error> {
match self.parse_value() {
Ok(value) => {
// Skip trailing whitespaces.
self.parse_whitespace();
// Make sure there is no trailing characters.
if self.eof() {
Ok(value)
} else {
self.error(~"trailing characters")
}
}
Err(e) => Err(e)
}
}
}
priv impl Parser {
fn eof(&self) -> bool { self.ch == -1 as char }
fn bump(&self) {
self.ch = self.rdr.read_char();
if self.ch == '\n' {
self.line += 1u;
self.col = 1u;
} else {
self.col += 1u;
}
}
fn next_char(&self) -> char {
self.bump();
self.ch
}
fn error<T>(&self, msg: ~str) -> Result<T, Error> {
Err(Error { line: self.line, col: self.col, msg: @msg })
}
fn parse_value(&self) -> Result<Json, Error> {
self.parse_whitespace();
if self.eof() { return self.error(~"EOF while parsing value"); }
match self.ch {
'n' => self.parse_ident(~"ull", Null),
't' => self.parse_ident(~"rue", Boolean(true)),
'f' => self.parse_ident(~"alse", Boolean(false)),
'0' .. '9' | '-' => self.parse_number(),
'"' =>
match self.parse_str() {
Ok(s) => Ok(String(s)),
Err(e) => Err(e),
},
'[' => self.parse_list(),
'{' => self.parse_object(),
_ => self.error(~"invalid syntax")
}
}
fn parse_whitespace(&self) {
while char::is_whitespace(self.ch) { self.bump(); }
}
fn parse_ident(&self, ident: &str, value: Json) -> Result<Json, Error> {
if str::all(ident, |c| c == self.next_char()) {
self.bump();
Ok(value)
} else {
self.error(~"invalid syntax")
}
}
fn parse_number(&self) -> Result<Json, Error> {
let mut neg = 1f;
if self.ch == '-' {
self.bump();
neg = -1f;
}
let mut res = match self.parse_integer() {
Ok(res) => res,
Err(e) => return Err(e)
};
if self.ch == '.' {
match self.parse_decimal(res) {
Ok(r) => res = r,
Err(e) => return Err(e)
}
}
if self.ch == 'e' || self.ch == 'E' {
match self.parse_exponent(res) {
Ok(r) => res = r,
Err(e) => return Err(e)
}
}
Ok(Number(neg * res))
}
fn parse_integer(&self) -> Result<float, Error> {
let mut res = 0f;
match self.ch {
'0' => {
self.bump();
// There can be only one leading '0'.
match self.ch {
'0' .. '9' => return self.error(~"invalid number"),
_ => ()
}
}
'1' .. '9' => {
while !self.eof() {
match self.ch {
'0' .. '9' => {
res *= 10f;
res += ((self.ch as int) - ('0' as int)) as float;
self.bump();
}
_ => break
}
}
}
_ => return self.error(~"invalid number")
}
Ok(res)
}
fn parse_decimal(&self, res: float) -> Result<float, Error> {
self.bump();
// Make sure a digit follows the decimal place.
match self.ch {
'0' .. '9' => (),
_ => return self.error(~"invalid number")
}
let mut res = res;
let mut dec = 1f;
while !self.eof() {
match self.ch {
'0' .. '9' => {
dec /= 10f;
res += (((self.ch as int) - ('0' as int)) as float) * dec;
self.bump();
}
_ => break
}
}
Ok(res)
}
fn parse_exponent(&self, res: float) -> Result<float, Error> {
self.bump();
let mut res = res;
let mut exp = 0u;
let mut neg_exp = false;
match self.ch {
'+' => self.bump(),
'-' => { self.bump(); neg_exp = true; }
_ => ()
}
// Make sure a digit follows the exponent place.
match self.ch {
'0' .. '9' => (),
_ => return self.error(~"invalid number")
}
while !self.eof() {
match self.ch {
'0' .. '9' => {
exp *= 10u;
exp += (self.ch as uint) - ('0' as uint);
self.bump();
}
_ => break
}
}
let exp = float::pow_with_uint(10u, exp);
if neg_exp {
res /= exp;
} else {
res *= exp;
}
Ok(res)
}
fn parse_str(&self) -> Result<~str, Error> {
let mut escape = false;
let mut res = ~"";
while !self.eof() {
self.bump();
if (escape) {
match self.ch {
'"' => str::push_char(&mut res, '"'),
'\\' => str::push_char(&mut res, '\\'),
'/' => str::push_char(&mut res, '/'),
'b' => str::push_char(&mut res, '\x08'),
'f' => str::push_char(&mut res, '\x0c'),
'n' => str::push_char(&mut res, '\n'),
'r' => str::push_char(&mut res, '\r'),
't' => str::push_char(&mut res, '\t'),
'u' => {
// Parse \u1234.
let mut i = 0u;
let mut n = 0u;
while i < 4u {
match self.next_char() {
'0' .. '9' => {
n = n * 16u + (self.ch as uint)
- ('0' as uint);
},
'a' | 'A' => n = n * 16u + 10u,
'b' | 'B' => n = n * 16u + 11u,
'c' | 'C' => n = n * 16u + 12u,
'd' | 'D' => n = n * 16u + 13u,
'e' | 'E' => n = n * 16u + 14u,
'f' | 'F' => n = n * 16u + 15u,
_ => return self.error(
~"invalid \\u escape (unrecognized hex)")
}
i += 1u;
}
// Error out if we didn't parse 4 digits.
if i != 4u {
return self.error(
~"invalid \\u escape (not four digits)");
}
str::push_char(&mut res, n as char);
}
_ => return self.error(~"invalid escape")
}
escape = false;
} else if self.ch == '\\' {
escape = true;
} else {
if self.ch == '"' {
self.bump();
return Ok(res);
}
str::push_char(&mut res, self.ch);
}
}
self.error(~"EOF while parsing string")
}
fn parse_list(&self) -> Result<Json, Error> {
self.bump();
self.parse_whitespace();
let mut values = ~[];
if self.ch == ']' {
self.bump();
return Ok(List(values));
}
loop {
match self.parse_value() {
Ok(v) => values.push(v),
Err(e) => return Err(e)
}
self.parse_whitespace();
if self.eof() {
return self.error(~"EOF while parsing list");
}
match self.ch {
',' => self.bump(),
']' => { self.bump(); return Ok(List(values)); }
_ => return self.error(~"expected `,` or `]`")
}
};
}
fn parse_object(&self) -> Result<Json, Error> {
self.bump();
self.parse_whitespace();
let mut values = ~LinearMap::new();
if self.ch == '}' {
self.bump();
return Ok(Object(values));
}
while !self.eof() {
self.parse_whitespace();
if self.ch != '"' {
return self.error(~"key must be a string");
}
let key = match self.parse_str() {
Ok(key) => key,
Err(e) => return Err(e)
};
self.parse_whitespace();
if self.ch != ':' {
if self.eof() { break; }
return self.error(~"expected `:`");
}
self.bump();
match self.parse_value() {
Ok(value) => { values.insert(key, value); }
Err(e) => return Err(e)
}
self.parse_whitespace();
match self.ch {
',' => self.bump(),
'}' => { self.bump(); return Ok(Object(values)); }
_ => {
if self.eof() { break; }
return self.error(~"expected `,` or `}`");
}
}
}
return self.error(~"EOF while parsing object");
}
}
/// Decodes a json value from an @io::Reader
pub fn from_reader(rdr: @io::Reader) -> Result<Json, Error> {
Parser(rdr).parse()
}
/// Decodes a json value from a string
pub fn from_str(s: &str) -> Result<Json, Error> {
do io::with_str_reader(s) |rdr| {
from_reader(rdr)
}
}
pub struct Decoder {
priv mut stack: ~[Json],
}
pub fn Decoder(json: Json) -> Decoder {
Decoder { stack: ~[json] }
}
impl serialize::Decoder for Decoder {
fn read_nil(&self) -> () {
debug!("read_nil");
match self.stack.pop() {
Null => (),
value => fail!(fmt!("not a null: %?", value))
}
}
fn read_u64(&self) -> u64 { self.read_float() as u64 }
fn read_u32(&self) -> u32 { self.read_float() as u32 }
fn read_u16(&self) -> u16 { self.read_float() as u16 }
fn read_u8 (&self) -> u8 { self.read_float() as u8 }
fn read_uint(&self) -> uint { self.read_float() as uint }
fn read_i64(&self) -> i64 { self.read_float() as i64 }
fn read_i32(&self) -> i32 { self.read_float() as i32 }
fn read_i16(&self) -> i16 { self.read_float() as i16 }
fn read_i8 (&self) -> i8 { self.read_float() as i8 }
fn read_int(&self) -> int { self.read_float() as int }
fn read_bool(&self) -> bool {
debug!("read_bool");
match self.stack.pop() {
Boolean(b) => b,
value => fail!(fmt!("not a boolean: %?", value))
}
}
fn read_f64(&self) -> f64 { self.read_float() as f64 }
fn read_f32(&self) -> f32 { self.read_float() as f32 }
fn read_float(&self) -> float {
debug!("read_float");
match self.stack.pop() {
Number(f) => f,
value => fail!(fmt!("not a number: %?", value))
}
}
fn read_char(&self) -> char {
let mut v = ~[];
for str::each_char(self.read_str()) |c| { v.push(c) }
if v.len() != 1 { fail!(~"string must have one character") }
v[0]
}
fn read_str(&self) -> ~str {
debug!("read_str");
match self.stack.pop() {
String(s) => s,
json => fail!(fmt!("not a string: %?", json))
}
}
fn read_enum<T>(&self, name: &str, f: &fn() -> T) -> T {
debug!("read_enum(%s)", name);
f()
}
fn read_enum_variant<T>(&self, names: &[&str], f: &fn(uint) -> T) -> T {
debug!("read_enum_variant(names=%?)", names);
let name = match self.stack.pop() {
String(s) => s,
List(list) => {
do vec::consume_reverse(list) |_i, v| {
self.stack.push(v);
}
match self.stack.pop() {
String(s) => s,
value => fail!(fmt!("invalid variant name: %?", value)),
}
}
ref json => fail!(fmt!("invalid variant: %?", *json)),
};
let idx = match vec::position(names, |n| str::eq_slice(*n, name)) {
Some(idx) => idx,
None => fail!(fmt!("Unknown variant name: %?", name)),
};
f(idx)
}
fn read_enum_variant_arg<T>(&self, idx: uint, f: &fn() -> T) -> T {
debug!("read_enum_variant_arg(idx=%u)", idx);
f()
}
fn read_seq<T>(&self, f: &fn(uint) -> T) -> T {
debug!("read_seq()");
let len = match self.stack.pop() {
List(list) => {
let len = list.len();
do vec::consume_reverse(list) |_i, v| {
self.stack.push(v);
}
len
}
_ => fail!(~"not a list"),
};
f(len)
}
fn read_seq_elt<T>(&self, idx: uint, f: &fn() -> T) -> T {
debug!("read_seq_elt(idx=%u)", idx);
f()
}
fn read_struct<T>(&self, name: &str, len: uint, f: &fn() -> T) -> T {
debug!("read_struct(name=%s, len=%u)", name, len);
let value = f();
self.stack.pop();
value
}
fn read_field<T>(&self, name: &str, idx: uint, f: &fn() -> T) -> T {
debug!("read_field(%s, idx=%u)", name, idx);
match self.stack.pop() {
Object(obj) => {
let mut obj = obj;
let value = match obj.pop(&name.to_owned()) {
None => fail!(fmt!("no such field: %s", name)),
Some(json) => {
self.stack.push(json);
f()
}
};
self.stack.push(Object(obj));
value
}
value => fail!(fmt!("not an object: %?", value))
}
}
fn read_option<T>(&self, f: &fn(bool) -> T) -> T {
match self.stack.pop() {
Null => f(false),
value => { self.stack.push(value); f(true) }
}
}
fn read_map<T>(&self, f: &fn(uint) -> T) -> T {
debug!("read_map()");
let len = match self.stack.pop() {
Object(obj) => {
let mut obj = obj;
let len = obj.len();
do obj.consume |key, value| {
self.stack.push(value);
self.stack.push(String(key));
}
len
}
json => fail!(fmt!("not an object: %?", json)),
};
f(len)
}
fn read_map_elt_key<T>(&self, idx: uint, f: &fn() -> T) -> T {
debug!("read_map_elt_key(idx=%u)", idx);
f()
}
fn read_map_elt_val<T>(&self, idx: uint, f: &fn() -> T) -> T {
debug!("read_map_elt_val(idx=%u)", idx);
f()
}
}
impl Eq for Json {
fn eq(&self, other: &Json) -> bool {
match (self) {
&Number(f0) =>
match other { &Number(f1) => f0 == f1, _ => false },
&String(ref s0) =>
match other { &String(ref s1) => s0 == s1, _ => false },
&Boolean(b0) =>
match other { &Boolean(b1) => b0 == b1, _ => false },
&Null =>
match other { &Null => true, _ => false },
&List(ref v0) =>
match other { &List(ref v1) => v0 == v1, _ => false },
&Object(ref d0) => {
match other {
&Object(ref d1) => {
if d0.len() == d1.len() {
let mut equal = true;
for d0.each |&(k, v0)| {
match d1.find(k) {
Some(v1) if v0 == v1 => { },
_ => { equal = false; break }
}
};
equal
} else {
false
}
}
_ => false
}
}
}
}
fn ne(&self, other: &Json) -> bool { !self.eq(other) }
}
/// Test if two json values are less than one another
impl Ord for Json {
fn lt(&self, other: &Json) -> bool {
match (*self) {
Number(f0) => {
match *other {
Number(f1) => f0 < f1,
String(_) | Boolean(_) | List(_) | Object(_) |
Null => true
}
}
String(ref s0) => {
match *other {
Number(_) => false,
String(ref s1) => s0 < s1,
Boolean(_) | List(_) | Object(_) | Null => true
}
}
Boolean(b0) => {
match *other {
Number(_) | String(_) => false,
Boolean(b1) => b0 < b1,
List(_) | Object(_) | Null => true
}
}
List(ref l0) => {
match *other {
Number(_) | String(_) | Boolean(_) => false,
List(ref l1) => (*l0) < (*l1),
Object(_) | Null => true
}
}
Object(ref d0) => {
match *other {
Number(_) | String(_) | Boolean(_) | List(_) => false,
Object(ref d1) => {
unsafe {
let mut d0_flat = ~[];
let mut d1_flat = ~[];
// FIXME #4430: this is horribly inefficient...
for d0.each |&(k, v)| {
d0_flat.push((@copy *k, @copy *v));
}
d0_flat.qsort();
for d1.each |&(k, v)| {
d1_flat.push((@copy *k, @copy *v));
}
d1_flat.qsort();
d0_flat < d1_flat
}
}
Null => true
}
}
Null => {
match *other {
Number(_) | String(_) | Boolean(_) | List(_) |
Object(_) =>
false,
Null => true
}
}
}
}
fn le(&self, other: &Json) -> bool { !(*other).lt(&(*self)) }
fn ge(&self, other: &Json) -> bool { !(*self).lt(other) }
fn gt(&self, other: &Json) -> bool { (*other).lt(&(*self)) }
}
trait ToJson { fn to_json(&self) -> Json; }
impl ToJson for Json {
fn to_json(&self) -> Json { copy *self }
}
impl ToJson for @Json {
fn to_json(&self) -> Json { (**self).to_json() }
}
impl ToJson for int {
fn to_json(&self) -> Json { Number(*self as float) }
}
impl ToJson for i8 {
fn to_json(&self) -> Json { Number(*self as float) }
}
impl ToJson for i16 {
fn to_json(&self) -> Json { Number(*self as float) }
}
impl ToJson for i32 {
fn to_json(&self) -> Json { Number(*self as float) }
}
impl ToJson for i64 {
fn to_json(&self) -> Json { Number(*self as float) }
}
impl ToJson for uint {
fn to_json(&self) -> Json { Number(*self as float) }
}
impl ToJson for u8 {
fn to_json(&self) -> Json { Number(*self as float) }
}
impl ToJson for u16 {
fn to_json(&self) -> Json { Number(*self as float) }
}
impl ToJson for u32 {
fn to_json(&self) -> Json { Number(*self as float) }
}
impl ToJson for u64 {
fn to_json(&self) -> Json { Number(*self as float) }
}
impl ToJson for float {
fn to_json(&self) -> Json { Number(*self) }
}
impl ToJson for f32 {
fn to_json(&self) -> Json { Number(*self as float) }
}
impl ToJson for f64 {
fn to_json(&self) -> Json { Number(*self as float) }
}
impl ToJson for () {
fn to_json(&self) -> Json { Null }
}
impl ToJson for bool {
fn to_json(&self) -> Json { Boolean(*self) }
}
impl ToJson for ~str {
fn to_json(&self) -> Json { String(copy *self) }
}
impl ToJson for @~str {
fn to_json(&self) -> Json { String(copy **self) }
}
impl<A:ToJson,B:ToJson> ToJson for (A, B) {
fn to_json(&self) -> Json {
match *self {
(ref a, ref b) => {
List(~[a.to_json(), b.to_json()])
}
}
}
}
impl<A:ToJson,B:ToJson,C:ToJson> ToJson for (A, B, C) {
fn to_json(&self) -> Json {
match *self {
(ref a, ref b, ref c) => {
List(~[a.to_json(), b.to_json(), c.to_json()])
}
}
}
}
impl<A:ToJson> ToJson for ~[A] {
fn to_json(&self) -> Json { List(self.map(|elt| elt.to_json())) }
}
impl<A:ToJson + Copy> ToJson for LinearMap<~str, A> {
fn to_json(&self) -> Json {
let mut d = LinearMap::new();
for self.each |&(key, value)| {
d.insert(copy *key, value.to_json());
}
Object(~d)
}
}
impl<A:ToJson> ToJson for Option<A> {
fn to_json(&self) -> Json {
match *self {
None => Null,
Some(ref value) => value.to_json()
}
}
}
impl to_str::ToStr for Json {
fn to_str(&self) -> ~str { to_str(self) }
}
impl to_str::ToStr for Error {
fn to_str(&self) -> ~str {
fmt!("%u:%u: %s", self.line, self.col, *self.msg)
}
}
#[cfg(test)]
mod tests {
use super::*;
use core::prelude::*;
use core::hashmap::linear::LinearMap;
use std::serialize::Decodable;
#[auto_encode]
#[auto_decode]
#[deriving(Eq)]
enum Animal {
Dog,
Frog(~str, int)
}
#[auto_encode]
#[auto_decode]
#[deriving(Eq)]
struct Inner {
a: (),
b: uint,
c: ~[~str],
}
#[auto_encode]
#[auto_decode]
#[deriving(Eq)]
struct Outer {
inner: ~[Inner],
}
fn mk_object(items: &[(~str, Json)]) -> Json {
let mut d = ~LinearMap::new();
for items.each |item| {
match *item {
(copy key, copy value) => { d.insert(key, value); },
}
};
Object(d)
}
#[test]
fn test_write_null() {
assert_eq!(to_str(&Null), ~"null");
assert_eq!(to_pretty_str(&Null), ~"null");
}
#[test]
fn test_write_number() {
assert_eq!(to_str(&Number(3f)), ~"3");
assert_eq!(to_pretty_str(&Number(3f)), ~"3");
assert_eq!(to_str(&Number(3.1f)), ~"3.1");
assert_eq!(to_pretty_str(&Number(3.1f)), ~"3.1");
assert_eq!(to_str(&Number(-1.5f)), ~"-1.5");
assert_eq!(to_pretty_str(&Number(-1.5f)), ~"-1.5");
assert_eq!(to_str(&Number(0.5f)), ~"0.5");
assert_eq!(to_pretty_str(&Number(0.5f)), ~"0.5");
}
#[test]
fn test_write_str() {
assert_eq!(to_str(&String(~"")), ~"\"\"");
assert_eq!(to_pretty_str(&String(~"")), ~"\"\"");
assert_eq!(to_str(&String(~"foo")), ~"\"foo\"");
assert_eq!(to_pretty_str(&String(~"foo")), ~"\"foo\"");
}
#[test]
fn test_write_bool() {
assert_eq!(to_str(&Boolean(true)), ~"true");
assert_eq!(to_pretty_str(&Boolean(true)), ~"true");
assert_eq!(to_str(&Boolean(false)), ~"false");
assert_eq!(to_pretty_str(&Boolean(false)), ~"false");
}
#[test]
fn test_write_list() {
assert_eq!(to_str(&List(~[])), ~"[]");
assert_eq!(to_pretty_str(&List(~[])), ~"[]");
assert_eq!(to_str(&List(~[Boolean(true)])), ~"[true]");
assert_eq!(
to_pretty_str(&List(~[Boolean(true)])),
~"\
[\n \
true\n\
]"
);
assert_eq!(to_str(&List(~[
Boolean(false),
Null,
List(~[String(~"foo\nbar"), Number(3.5f)])
])), ~"[false,null,[\"foo\\nbar\",3.5]]");
assert_eq!(
to_pretty_str(&List(~[
Boolean(false),
Null,
List(~[String(~"foo\nbar"), Number(3.5f)])
])),
~"\
[\n \
false,\n \
null,\n \
[\n \
\"foo\\nbar\",\n \
3.5\n \
]\n\
]"
);
}
#[test]
fn test_write_object() {
assert_eq!(to_str(&mk_object(~[])), ~"{}");
assert_eq!(to_pretty_str(&mk_object(~[])), ~"{}");
assert_eq!(
to_str(&mk_object(~[(~"a", Boolean(true))])),
~"{\"a\":true}"
);
assert_eq!(
to_pretty_str(&mk_object(~[(~"a", Boolean(true))])),
~"\
{\n \
\"a\": true\n\
}"
);
assert_eq!(
to_str(&mk_object(~[
(~"b", List(~[
mk_object(~[(~"c", String(~"\x0c\r"))]),
mk_object(~[(~"d", String(~""))])
]))
])),
~"{\
\"b\":[\
{\"c\":\"\\f\\r\"},\
{\"d\":\"\"}\
]\
}"
);
assert_eq!(
to_pretty_str(&mk_object(~[
(~"b", List(~[
mk_object(~[(~"c", String(~"\x0c\r"))]),
mk_object(~[(~"d", String(~""))])
]))
])),
~"\
{\n \
\"b\": [\n \
{\n \
\"c\": \"\\f\\r\"\n \
},\n \
{\n \
\"d\": \"\"\n \
}\n \
]\n\
}"
);
let a = mk_object(~[
(~"a", Boolean(true)),
(~"b", List(~[
mk_object(~[(~"c", String(~"\x0c\r"))]),
mk_object(~[(~"d", String(~""))])
]))
]);
// We can't compare the strings directly because the object fields be
// printed in a different order.
assert_eq!(copy a, from_str(to_str(&a)).unwrap());
assert_eq!(copy a, from_str(to_pretty_str(&a)).unwrap());
}
#[test]
fn test_write_enum() {
let animal = Dog;
assert_eq!(
do io::with_str_writer |wr| {
let encoder = Encoder(wr);
animal.encode(&encoder);
},
~"\"Dog\""
);
assert_eq!(
do io::with_str_writer |wr| {
let encoder = PrettyEncoder(wr);
animal.encode(&encoder);
},
~"\"Dog\""
);
let animal = Frog(~"Henry", 349);
assert_eq!(
do io::with_str_writer |wr| {
let encoder = Encoder(wr);
animal.encode(&encoder);
},
~"[\"Frog\",\"Henry\",349]"
);
assert_eq!(
do io::with_str_writer |wr| {
let encoder = PrettyEncoder(wr);
animal.encode(&encoder);
},
~"\
[\n \
\"Frog\",\n \
\"Henry\",\n \
349\n\
]"
);
}
#[test]
fn test_write_some() {
let value = Some(~"jodhpurs");
let s = do io::with_str_writer |wr| {
let encoder = Encoder(wr);
value.encode(&encoder);
};
assert_eq!(s, ~"\"jodhpurs\"");
let value = Some(~"jodhpurs");
let s = do io::with_str_writer |wr| {
let encoder = PrettyEncoder(wr);
value.encode(&encoder);
};
assert_eq!(s, ~"\"jodhpurs\"");
}
#[test]
fn test_write_none() {
let value: Option<~str> = None;
let s = do io::with_str_writer |wr| {
let encoder = Encoder(wr);
value.encode(&encoder);
};
assert_eq!(s, ~"null");
let s = do io::with_str_writer |wr| {
let encoder = Encoder(wr);
value.encode(&encoder);
};
assert_eq!(s, ~"null");
}
#[test]
fn test_trailing_characters() {
assert_eq!(from_str(~"nulla"),
Err(Error {line: 1u, col: 5u, msg: @~"trailing characters"}));
assert_eq!(from_str(~"truea"),
Err(Error {line: 1u, col: 5u, msg: @~"trailing characters"}));
assert_eq!(from_str(~"falsea"),
Err(Error {line: 1u, col: 6u, msg: @~"trailing characters"}));
assert_eq!(from_str(~"1a"),
Err(Error {line: 1u, col: 2u, msg: @~"trailing characters"}));
assert_eq!(from_str(~"[]a"),
Err(Error {line: 1u, col: 3u, msg: @~"trailing characters"}));
assert_eq!(from_str(~"{}a"),
Err(Error {line: 1u, col: 3u, msg: @~"trailing characters"}));
}
#[test]
fn test_read_identifiers() {
assert_eq!(from_str(~"n"),
Err(Error {line: 1u, col: 2u, msg: @~"invalid syntax"}));
assert_eq!(from_str(~"nul"),
Err(Error {line: 1u, col: 4u, msg: @~"invalid syntax"}));
assert_eq!(from_str(~"t"),
Err(Error {line: 1u, col: 2u, msg: @~"invalid syntax"}));
assert_eq!(from_str(~"truz"),
Err(Error {line: 1u, col: 4u, msg: @~"invalid syntax"}));
assert_eq!(from_str(~"f"),
Err(Error {line: 1u, col: 2u, msg: @~"invalid syntax"}));
assert_eq!(from_str(~"faz"),
Err(Error {line: 1u, col: 3u, msg: @~"invalid syntax"}));
assert_eq!(from_str(~"null"), Ok(Null));
assert_eq!(from_str(~"true"), Ok(Boolean(true)));
assert_eq!(from_str(~"false"), Ok(Boolean(false)));
assert_eq!(from_str(~" null "), Ok(Null));
assert_eq!(from_str(~" true "), Ok(Boolean(true)));
assert_eq!(from_str(~" false "), Ok(Boolean(false)));
}
#[test]
fn test_decode_identifiers() {
let v: () = Decodable::decode(&Decoder(from_str(~"null").unwrap()));
assert_eq!(v, ());
let v: bool = Decodable::decode(&Decoder(from_str(~"true").unwrap()));
assert_eq!(v, true);
let v: bool = Decodable::decode(&Decoder(from_str(~"false").unwrap()));
assert_eq!(v, false);
}
#[test]
fn test_read_number() {
assert_eq!(from_str(~"+"),
Err(Error {line: 1u, col: 1u, msg: @~"invalid syntax"}));
assert_eq!(from_str(~"."),
Err(Error {line: 1u, col: 1u, msg: @~"invalid syntax"}));
assert_eq!(from_str(~"-"),
Err(Error {line: 1u, col: 2u, msg: @~"invalid number"}));
assert_eq!(from_str(~"00"),
Err(Error {line: 1u, col: 2u, msg: @~"invalid number"}));
assert_eq!(from_str(~"1."),
Err(Error {line: 1u, col: 3u, msg: @~"invalid number"}));
assert_eq!(from_str(~"1e"),
Err(Error {line: 1u, col: 3u, msg: @~"invalid number"}));
assert_eq!(from_str(~"1e+"),
Err(Error {line: 1u, col: 4u, msg: @~"invalid number"}));
assert_eq!(from_str(~"3"), Ok(Number(3f)));
assert_eq!(from_str(~"3.1"), Ok(Number(3.1f)));
assert_eq!(from_str(~"-1.2"), Ok(Number(-1.2f)));
assert_eq!(from_str(~"0.4"), Ok(Number(0.4f)));
assert_eq!(from_str(~"0.4e5"), Ok(Number(0.4e5f)));
assert_eq!(from_str(~"0.4e+15"), Ok(Number(0.4e15f)));
assert_eq!(from_str(~"0.4e-01"), Ok(Number(0.4e-01f)));
assert_eq!(from_str(~" 3 "), Ok(Number(3f)));
}
#[test]
fn test_decode_numbers() {
let v: float = Decodable::decode(&Decoder(from_str(~"3").unwrap()));
assert_eq!(v, 3f);
let v: float = Decodable::decode(&Decoder(from_str(~"3.1").unwrap()));
assert_eq!(v, 3.1f);
let v: float = Decodable::decode(&Decoder(from_str(~"-1.2").unwrap()));
assert_eq!(v, -1.2f);
let v: float = Decodable::decode(&Decoder(from_str(~"0.4").unwrap()));
assert_eq!(v, 0.4f);
let v: float = Decodable::decode(&Decoder(from_str(~"0.4e5").unwrap()));
assert_eq!(v, 0.4e5f);
let v: float = Decodable::decode(&Decoder(from_str(~"0.4e15").unwrap()));
assert_eq!(v, 0.4e15f);
let v: float = Decodable::decode(&Decoder(from_str(~"0.4e-01").unwrap()));
assert_eq!(v, 0.4e-01f);
}
#[test]
fn test_read_str() {
assert_eq!(from_str(~"\""),
Err(Error {line: 1u, col: 2u, msg: @~"EOF while parsing string"
}));
assert_eq!(from_str(~"\"lol"),
Err(Error {line: 1u, col: 5u, msg: @~"EOF while parsing string"
}));
assert_eq!(from_str(~"\"\""), Ok(String(~"")));
assert_eq!(from_str(~"\"foo\""), Ok(String(~"foo")));
assert_eq!(from_str(~"\"\\\"\""), Ok(String(~"\"")));
assert_eq!(from_str(~"\"\\b\""), Ok(String(~"\x08")));
assert_eq!(from_str(~"\"\\n\""), Ok(String(~"\n")));
assert_eq!(from_str(~"\"\\r\""), Ok(String(~"\r")));
assert_eq!(from_str(~"\"\\t\""), Ok(String(~"\t")));
assert_eq!(from_str(~" \"foo\" "), Ok(String(~"foo")));
assert_eq!(from_str(~"\"\\u12ab\""), Ok(String(~"\u12ab")));
assert_eq!(from_str(~"\"\\uAB12\""), Ok(String(~"\uAB12")));
}
#[test]
fn test_decode_str() {
let v: ~str = Decodable::decode(&Decoder(from_str(~"\"\"").unwrap()));
assert_eq!(v, ~"");
let v: ~str = Decodable::decode(&Decoder(from_str(~"\"foo\"").unwrap()));
assert_eq!(v, ~"foo");
let v: ~str = Decodable::decode(&Decoder(from_str(~"\"\\\"\"").unwrap()));
assert_eq!(v, ~"\"");
let v: ~str = Decodable::decode(&Decoder(from_str(~"\"\\b\"").unwrap()));
assert_eq!(v, ~"\x08");
let v: ~str = Decodable::decode(&Decoder(from_str(~"\"\\n\"").unwrap()));
assert_eq!(v, ~"\n");
let v: ~str = Decodable::decode(&Decoder(from_str(~"\"\\r\"").unwrap()));
assert_eq!(v, ~"\r");
let v: ~str = Decodable::decode(&Decoder(from_str(~"\"\\t\"").unwrap()));
assert_eq!(v, ~"\t");
let v: ~str = Decodable::decode(&Decoder(from_str(~"\"\\u12ab\"").unwrap()));
assert_eq!(v, ~"\u12ab");
let v: ~str = Decodable::decode(&Decoder(from_str(~"\"\\uAB12\"").unwrap()));
assert_eq!(v, ~"\uAB12");
}
#[test]
fn test_read_list() {
assert_eq!(from_str(~"["),
Err(Error {line: 1u, col: 2u, msg: @~"EOF while parsing value"}));
assert_eq!(from_str(~"[1"),
Err(Error {line: 1u, col: 3u, msg: @~"EOF while parsing list"}));
assert_eq!(from_str(~"[1,"),
Err(Error {line: 1u, col: 4u, msg: @~"EOF while parsing value"}));
assert_eq!(from_str(~"[1,]"),
Err(Error {line: 1u, col: 4u, msg: @~"invalid syntax"}));
assert_eq!(from_str(~"[6 7]"),
Err(Error {line: 1u, col: 4u, msg: @~"expected `,` or `]`"}));
assert_eq!(from_str(~"[]"), Ok(List(~[])));
assert_eq!(from_str(~"[ ]"), Ok(List(~[])));
assert_eq!(from_str(~"[true]"), Ok(List(~[Boolean(true)])));
assert_eq!(from_str(~"[ false ]"), Ok(List(~[Boolean(false)])));
assert_eq!(from_str(~"[null]"), Ok(List(~[Null])));
assert_eq!(from_str(~"[3, 1]"),
Ok(List(~[Number(3f), Number(1f)])));
assert_eq!(from_str(~"\n[3, 2]\n"),
Ok(List(~[Number(3f), Number(2f)])));
assert_eq!(from_str(~"[2, [4, 1]]"),
Ok(List(~[Number(2f), List(~[Number(4f), Number(1f)])])));
}
#[test]
fn test_decode_list() {
let v: ~[()] = Decodable::decode(&Decoder(from_str(~"[]").unwrap()));
assert_eq!(v, ~[]);
let v: ~[()] = Decodable::decode(&Decoder(from_str(~"[null]").unwrap()));
assert_eq!(v, ~[()]);
let v: ~[bool] = Decodable::decode(&Decoder(from_str(~"[true]").unwrap()));
assert_eq!(v, ~[true]);
let v: ~[bool] = Decodable::decode(&Decoder(from_str(~"[true]").unwrap()));
assert_eq!(v, ~[true]);
let v: ~[int] = Decodable::decode(&Decoder(from_str(~"[3, 1]").unwrap()));
assert_eq!(v, ~[3, 1]);
let v: ~[~[uint]] = Decodable::decode(&Decoder(from_str(~"[[3], [1, 2]]").unwrap()));
assert_eq!(v, ~[~[3], ~[1, 2]]);
}
#[test]
fn test_read_object() {
assert_eq!(from_str(~"{"),
Err(Error {
line: 1u,
col: 2u,
msg: @~"EOF while parsing object"}));
assert_eq!(from_str(~"{ "),
Err(Error {
line: 1u,
col: 3u,
msg: @~"EOF while parsing object"}));
assert_eq!(from_str(~"{1"),
Err(Error {
line: 1u,
col: 2u,
msg: @~"key must be a string"}));
assert_eq!(from_str(~"{ \"a\""),
Err(Error {
line: 1u,
col: 6u,
msg: @~"EOF while parsing object"}));
assert_eq!(from_str(~"{\"a\""),
Err(Error {
line: 1u,
col: 5u,
msg: @~"EOF while parsing object"}));
assert_eq!(from_str(~"{\"a\" "),
Err(Error {
line: 1u,
col: 6u,
msg: @~"EOF while parsing object"}));
assert_eq!(from_str(~"{\"a\" 1"),
Err(Error {line: 1u, col: 6u, msg: @~"expected `:`"}));
assert_eq!(from_str(~"{\"a\":"),
Err(Error {line: 1u, col: 6u, msg: @~"EOF while parsing value"}));
assert_eq!(from_str(~"{\"a\":1"),
Err(Error {
line: 1u,
col: 7u,
msg: @~"EOF while parsing object"}));
assert_eq!(from_str(~"{\"a\":1 1"),
Err(Error {line: 1u, col: 8u, msg: @~"expected `,` or `}`"}));
assert_eq!(from_str(~"{\"a\":1,"),
Err(Error {
line: 1u,
col: 8u,
msg: @~"EOF while parsing object"}));
assert_eq!(result::unwrap(from_str(~"{}")), mk_object(~[]));
assert_eq!(result::unwrap(from_str(~"{\"a\": 3}")),
mk_object(~[(~"a", Number(3.0f))]));
assert_eq!(result::unwrap(from_str(
~"{ \"a\": null, \"b\" : true }")),
mk_object(~[
(~"a", Null),
(~"b", Boolean(true))]));
assert_eq!(result::unwrap(
from_str(~"\n{ \"a\": null, \"b\" : true }\n")),
mk_object(~[
(~"a", Null),
(~"b", Boolean(true))]));
assert_eq!(result::unwrap(from_str(
~"{\"a\" : 1.0 ,\"b\": [ true ]}")),
mk_object(~[
(~"a", Number(1.0)),
(~"b", List(~[Boolean(true)]))
]));
assert_eq!(result::unwrap(from_str(
~"{" +
~"\"a\": 1.0, " +
~"\"b\": [" +
~"true," +
~"\"foo\\nbar\", " +
~"{ \"c\": {\"d\": null} } " +
~"]" +
~"}")),
mk_object(~[
(~"a", Number(1.0f)),
(~"b", List(~[
Boolean(true),
String(~"foo\nbar"),
mk_object(~[
(~"c", mk_object(~[(~"d", Null)]))
])
]))
]));
}
#[test]
fn test_decode_struct() {
let s = ~"{
\"inner\": [
{ \"a\": null, \"b\": 2, \"c\": [\"abc\", \"xyz\"] }
]
}";
let v: Outer = Decodable::decode(&Decoder(from_str(s).unwrap()));
assert_eq!(
v,
Outer {
inner: ~[
Inner { a: (), b: 2, c: ~[~"abc", ~"xyz"] }
]
}
);
}
#[test]
fn test_decode_option() {
let decoder = Decoder(from_str(~"null").unwrap());
let value: Option<~str> = Decodable::decode(&decoder);
assert_eq!(value, None);
let decoder = Decoder(from_str(~"\"jodhpurs\"").unwrap());
let value: Option<~str> = Decodable::decode(&decoder);
assert_eq!(value, Some(~"jodhpurs"));
}
#[test]
fn test_decode_enum() {
let decoder = Decoder(from_str(~"\"Dog\"").unwrap());
let value: Animal = Decodable::decode(&decoder);
assert_eq!(value, Dog);
let decoder = Decoder(from_str(~"[\"Frog\",\"Henry\",349]").unwrap());
let value: Animal = Decodable::decode(&decoder);
assert_eq!(value, Frog(~"Henry", 349));
}
#[test]
fn test_decode_map() {
let s = ~"{\"a\": \"Dog\", \"b\": [\"Frog\", \"Henry\", 349]}";
let decoder = Decoder(from_str(s).unwrap());
let mut map: LinearMap<~str, Animal> = Decodable::decode(&decoder);
assert_eq!(map.pop(&~"a"), Some(Dog));
assert_eq!(map.pop(&~"b"), Some(Frog(~"Henry", 349)));
}
#[test]
fn test_multiline_errors() {
assert_eq!(from_str(~"{\n \"foo\":\n \"bar\""),
Err(Error {
line: 3u,
col: 8u,
msg: @~"EOF while parsing object"}));
}
}