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// This is a part of rust-encoding.
// Copyright (c) 2013-2015, Kang Seonghoon.
// See README.md and LICENSE.txt for details.
//! Legacy traditional Chinese encodings.
use std::convert::Into;
use std::default::Default;
use util::StrCharIndex;
use index_tradchinese as index;
use types::*;
/**
* Big5-2003 with common extensions. (XXX with asymmetric HKSCS-2008 support)
*
* This is a traditional Chinese encoding spanning the region `[81-FE] [40-7E A1-FE]`.
* Originally a proprietary encoding by the consortium of five companies (hence the name),
* the Republic of China government standardized Big5-2003 in an appendix of CNS 11643
* so that CNS 11643 plane 1 and plane 2 have
* an almost identical set of characters as Big5 (but with a different mapping).
* The Hong Kong government has an official extension to Big5
* named Hong Kong Supplementary Character Set (HKSCS).
*
* This particular implementation of Big5 includes the widespread ETEN and HKSCS extensions,
* but excludes less common extensions such as Big5+, Big-5E and Unicode-at-on.
*/
#[derive(Clone, Copy)]
pub struct BigFive2003Encoding;
impl Encoding for BigFive2003Encoding {
fn name(&self) -> &'static str { "big5-2003" }
fn whatwg_name(&self) -> Option<&'static str> { Some("big5") } // WHATWG compatibility
fn raw_encoder(&self) -> Box<RawEncoder> { BigFive2003Encoder::new() }
fn raw_decoder(&self) -> Box<RawDecoder> { BigFive2003HKSCS2008Decoder::new() }
}
/// An encoder for Big5-2003.
#[derive(Clone, Copy)]
pub struct BigFive2003Encoder;
impl BigFive2003Encoder {
pub fn new() -> Box<RawEncoder> { Box::new(BigFive2003Encoder) }
}
impl RawEncoder for BigFive2003Encoder {
fn from_self(&self) -> Box<RawEncoder> { BigFive2003Encoder::new() }
fn is_ascii_compatible(&self) -> bool { true }
fn raw_feed(&mut self, input: &str, output: &mut ByteWriter) -> (usize, Option<CodecError>) {
output.writer_hint(input.len());
for ((i,j), ch) in input.index_iter() {
if ch < '\u{80}' {
output.write_byte(ch as u8);
} else {
let ptr = index::big5::backward(ch as u32);
if ptr == 0xffff || ptr < (0xa1 - 0x81) * 157 {
// no HKSCS extension (XXX doesn't HKSCS include 0xFA40..0xFEFE?)
return (i, Some(CodecError {
upto: j as isize, cause: "unrepresentable character".into()
}));
}
let lead = ptr / 157 + 0x81;
let trail = ptr % 157;
let trailoffset = if trail < 0x3f {0x40} else {0x62};
output.write_byte(lead as u8);
output.write_byte((trail + trailoffset) as u8);
}
}
(input.len(), None)
}
fn raw_finish(&mut self, _output: &mut ByteWriter) -> Option<CodecError> {
None
}
}
/// A decoder for Big5-2003 with HKSCS-2008 extension.
#[derive(Clone, Copy)]
struct BigFive2003HKSCS2008Decoder {
st: bigfive2003::State,
}
impl BigFive2003HKSCS2008Decoder {
pub fn new() -> Box<RawDecoder> {
Box::new(BigFive2003HKSCS2008Decoder { st: Default::default() })
}
}
impl RawDecoder for BigFive2003HKSCS2008Decoder {
fn from_self(&self) -> Box<RawDecoder> { BigFive2003HKSCS2008Decoder::new() }
fn is_ascii_compatible(&self) -> bool { true }
fn raw_feed(&mut self, input: &[u8], output: &mut StringWriter) -> (usize, Option<CodecError>) {
let (st, processed, err) = bigfive2003::raw_feed(self.st, input, output, &());
self.st = st;
(processed, err)
}
fn raw_finish(&mut self, output: &mut StringWriter) -> Option<CodecError> {
let (st, err) = bigfive2003::raw_finish(self.st, output, &());
self.st = st;
err
}
}
stateful_decoder! {
module bigfive2003;
internal pub fn map_two_bytes(lead: u8, trail: u8) -> u32 {
use index_tradchinese as index;
let lead = lead as u16;
let trail = trail as u16;
let index = match (lead, trail) {
(0x81...0xfe, 0x40...0x7e) | (0x81...0xfe, 0xa1...0xfe) => {
let trailoffset = if trail < 0x7f {0x40} else {0x62};
(lead - 0x81) * 157 + trail - trailoffset
}
_ => 0xffff,
};
index::big5::forward(index) // may return two-letter replacements 0..3
}
initial:
// big5 lead = 0x00
state S0(ctx: Context) {
case b @ 0x00...0x7f => ctx.emit(b as u32);
case b @ 0x81...0xfe => S1(ctx, b);
case _ => ctx.err("invalid sequence");
}
transient:
// big5 lead != 0x00
state S1(ctx: Context, lead: u8) {
case b => match map_two_bytes(lead, b) {
0xffff => {
let backup = if b < 0x80 {1} else {0};
ctx.backup_and_err(backup, "invalid sequence")
},
0 /*index=1133*/ => ctx.emit_str("\u{ca}\u{304}"),
1 /*index=1135*/ => ctx.emit_str("\u{ca}\u{30c}"),
2 /*index=1164*/ => ctx.emit_str("\u{ea}\u{304}"),
3 /*index=1166*/ => ctx.emit_str("\u{ea}\u{30c}"),
ch => ctx.emit(ch),
};
}
}
#[cfg(test)]
mod bigfive2003_tests {
extern crate test;
use super::BigFive2003Encoding;
use testutils;
use types::*;
#[test]
fn test_encoder_valid() {
let mut e = BigFive2003Encoding.raw_encoder();
assert_feed_ok!(e, "A", "", [0x41]);
assert_feed_ok!(e, "BC", "", [0x42, 0x43]);
assert_feed_ok!(e, "", "", []);
assert_feed_ok!(e, "\u{4e2d}\u{83ef}\u{6c11}\u{570b}", "",
[0xa4, 0xa4, 0xb5, 0xd8, 0xa5, 0xc1, 0xb0, 0xea]);
assert_feed_ok!(e, "1\u{20ac}/m", "", [0x31, 0xa3, 0xe1, 0x2f, 0x6d]);
assert_feed_ok!(e, "\u{ffed}", "", [0xf9, 0xfe]);
assert_finish_ok!(e, []);
}
#[test]
fn test_encoder_invalid() {
let mut e = BigFive2003Encoding.raw_encoder();
assert_feed_err!(e, "", "\u{ffff}", "", []);
assert_feed_err!(e, "?", "\u{ffff}", "!", [0x3f]);
assert_feed_err!(e, "", "\u{3eec}", "\u{4e00}", []); // HKSCS-2008 addition
assert_finish_ok!(e, []);
}
#[test]
fn test_decoder_valid() {
let mut d = BigFive2003Encoding.raw_decoder();
assert_feed_ok!(d, [0x41], [], "A");
assert_feed_ok!(d, [0x42, 0x43], [], "BC");
assert_feed_ok!(d, [], [], "");
assert_feed_ok!(d, [0xa4, 0xa4, 0xb5, 0xd8, 0xa5, 0xc1, 0xb0, 0xea], [],
"\u{4e2d}\u{83ef}\u{6c11}\u{570b}");
assert_feed_ok!(d, [], [0xa4], "");
assert_feed_ok!(d, [0xa4, 0xb5, 0xd8], [0xa5], "\u{4e2d}\u{83ef}");
assert_feed_ok!(d, [0xc1, 0xb0, 0xea], [], "\u{6c11}\u{570b}");
assert_feed_ok!(d, [0x31, 0xa3, 0xe1, 0x2f, 0x6d], [], "1\u{20ac}/m");
assert_feed_ok!(d, [0xf9, 0xfe], [], "\u{ffed}");
assert_feed_ok!(d, [0x87, 0x7e], [], "\u{3eec}"); // HKSCS-2008 addition
assert_feed_ok!(d, [0x88, 0x62, 0x88, 0x64, 0x88, 0xa3, 0x88, 0xa5], [],
"\u{ca}\u{304}\u{00ca}\u{30c}\u{ea}\u{304}\u{ea}\u{30c}"); // 2-byte output
assert_finish_ok!(d, "");
}
#[test]
fn test_decoder_invalid_lone_lead_immediate_test_finish() {
for i in 0x81..0xff {
let mut d = BigFive2003Encoding.raw_decoder();
assert_feed_ok!(d, [], [i], ""); // wait for a trail
assert_finish_err!(d, "");
}
// 80/FF: immediate failure
let mut d = BigFive2003Encoding.raw_decoder();
assert_feed_err!(d, [], [0x80], [], "");
assert_feed_err!(d, [], [0xff], [], "");
assert_finish_ok!(d, "");
}
#[test]
fn test_decoder_invalid_lone_lead_followed_by_space() {
for i in 0x80..0x100 {
let i = i as u8;
let mut d = BigFive2003Encoding.raw_decoder();
assert_feed_err!(d, [], [i], [0x20], "");
assert_finish_ok!(d, "");
}
}
#[test]
fn test_decoder_invalid_lead_followed_by_invalid_trail() {
// unlike most other cases, valid lead + invalid MSB-set trail are entirely consumed.
// https://www.w3.org/Bugs/Public/show_bug.cgi?id=16771
for i in 0x81..0xff {
let mut d = BigFive2003Encoding.raw_decoder();
assert_feed_err!(d, [], [i, 0x80], [0x20], "");
assert_feed_err!(d, [], [i, 0xff], [0x20], "");
assert_finish_ok!(d, "");
let mut d = BigFive2003Encoding.raw_decoder();
assert_feed_ok!(d, [], [i], "");
assert_feed_err!(d, [], [0x80], [0x20], "");
assert_feed_ok!(d, [], [i], "");
assert_feed_err!(d, [], [0xff], [0x20], "");
assert_finish_ok!(d, "");
}
// 80/FF is not a valid lead and the trail is not consumed
let mut d = BigFive2003Encoding.raw_decoder();
assert_feed_err!(d, [], [0x80], [0x80], "");
assert_feed_err!(d, [], [0x80], [0xff], "");
assert_feed_err!(d, [], [0xff], [0x80], "");
assert_feed_err!(d, [], [0xff], [0xff], "");
assert_finish_ok!(d, "");
}
#[test]
fn test_decoder_feed_after_finish() {
let mut d = BigFive2003Encoding.raw_decoder();
assert_feed_ok!(d, [0xa4, 0x40], [0xa4], "\u{4e00}");
assert_finish_err!(d, "");
assert_feed_ok!(d, [0xa4, 0x40], [], "\u{4e00}");
assert_finish_ok!(d, "");
}
#[bench]
fn bench_encode_short_text(bencher: &mut test::Bencher) {
let s = testutils::TRADITIONAL_CHINESE_TEXT;
bencher.bytes = s.len() as u64;
bencher.iter(|| test::black_box({
BigFive2003Encoding.encode(&s, EncoderTrap::Strict)
}))
}
#[bench]
fn bench_decode_short_text(bencher: &mut test::Bencher) {
let s = BigFive2003Encoding.encode(testutils::TRADITIONAL_CHINESE_TEXT,
EncoderTrap::Strict).ok().unwrap();
bencher.bytes = s.len() as u64;
bencher.iter(|| test::black_box({
BigFive2003Encoding.decode(&s, DecoderTrap::Strict)
}))
}
}