msime-engine 0.2.0

//! Chinese punctuation translation (core-session.md §5.6, overlays.md §7.1, `contracts/punctuation/policy.json`): a fixed map, alternating quotes, and nested book-title marks, with a second set of characters for the quote and square-bracket keys (`styles`) that the host picks from preferences. Quotes always alternate and book titles always nest, whether pairing is on or not; pairing only decides whether a host-side auto-close pays back the nesting count.

/// `policy.json` 的 `simple`，按文件顺序。前 15 行是第 1 版的表；第 5 版在末尾加了 `{` → 「、`}` → 」：`Shift+[` `Shift+]` 固定出左右直角引号，不交替、不随引号样式变（#10047）。
const SIMPLE: [(u8, &str); 17] = [
    (b',', "，"),
    (b'.', "。"),
    (b'?', "？"),
    (b'!', "！"),
    (b';', "；"),
    (b':', "："),
    (b'(', "（"),
    (b')', "）"),
    (b'[', "【"),
    (b']', "】"),
    (b'\\', "、"),
    (b'`', "·"),
    (b'$', "￥"),
    (b'^', "……"),
    (b'_', "——"),
    (b'{', "「"),
    (b'}', "」"),
];

const DOUBLE_QUOTE: (&str, &str) = ("“", "”");
const SINGLE_QUOTE: (&str, &str) = ("‘", "’");

/// `policy.json` 的 `styles.cornerQuotes`：直角引号下 `"` 和 `'` 的两组字。
const CORNER_DOUBLE_QUOTE: (&str, &str) = ("『", "』");
const CORNER_SINGLE_QUOTE: (&str, &str) = ("「", "」");

/// `policy.json` 的 `styles.hollowBrackets`：空心方头括号替换 `[` `]` 在 `SIMPLE` 里的字。
const HOLLOW_BRACKETS: [(u8, &str); 2] = [(b'[', "〖"), (b']', "〗")];

/// `policy.json` 第 4 版的 `enumerationComma`：可被偏好关掉的顿号键。`\` 同时在 `SIMPLE` 里（第 1 版起的无条件映射，`translate` 按开关拦它）；`/` 只在这一段，开关没打开时它是普通字符。
const ENUMERATION_COMMA: [(u8, &str); 2] = [(b'\\', "、"), (b'/', "、")];

/// 引号键出哪一组字。`Corner` 下 `'` 出「」、`"` 出『』，按键对应，不按语义对应。
#[derive(Debug, Clone, Copy, PartialEq, Eq, Default)]
pub enum QuoteMarks {
    #[default]
    Curly,
    Corner,
}

/// `[` `]` 出实心【】还是空心〖〗。
#[derive(Debug, Clone, Copy, PartialEq, Eq, Default)]
pub enum BracketMarks {
    #[default]
    Solid,
    Hollow,
}

/// 已经解析好的标点样式与顿号键：宿主从偏好算出它（`corner_when_traditional` 在那之前就按繁体开关定成两者之一，「至少留一个」也已归一），引擎只认确定的值。缺省就是契约第 1 版的表加「只有 `\` 出顿号」。
#[derive(Debug, Clone, Copy, PartialEq, Eq)]
pub struct PunctuationMarks {
    pub quotes: QuoteMarks,
    pub brackets: BracketMarks,
    /// `\` 键出顿号「、」。
    pub enumeration_comma_backslash: bool,
    /// `/` 键出顿号「、」。
    pub enumeration_comma_slash: bool,
}

impl Default for PunctuationMarks {
    fn default() -> Self {
        Self {
            quotes: QuoteMarks::Curly,
            brackets: BracketMarks::Solid,
            enumeration_comma_backslash: true,
            enumeration_comma_slash: false,
        }
    }
}

const NESTED_OPENING_INPUT: u8 = b'<';
const NESTED_CLOSING_INPUT: u8 = b'>';
const NESTED_OPENING: &str = "《";
const NESTED_OPENING_INNER: &str = "〈";
const NESTED_CLOSING: &str = "》";
const NESTED_CLOSING_INNER: &str = "〉";

#[derive(Debug, Clone)]
pub struct PunctuationPolicy {
    paired_enabled: bool,
    marks: PunctuationMarks,
    next_double_quote_is_opening: bool,
    next_single_quote_is_opening: bool,
    book_title_nesting: u32,
    /// 最近一次交替引号的按键；空闲退格若正好删掉这枚引号，可以把交替状态撤回。
    last_alternating_quote: Option<u8>,
}

impl Default for PunctuationPolicy {
    fn default() -> Self {
        Self {
            paired_enabled: true,
            marks: PunctuationMarks::default(),
            next_double_quote_is_opening: true,
            next_single_quote_is_opening: true,
            book_title_nesting: 0,
            last_alternating_quote: None,
        }
    }
}

impl PunctuationPolicy {
    /// 将 ASCII 按键转成中文标点并推进引号与嵌套状态；没有映射的键（如 `@`、`-`）返回 `None`。
    pub fn translate(&mut self, key: u8) -> Option<&'static str> {
        if self.marks.brackets == BracketMarks::Hollow {
            if let Some(&(_, output)) = HOLLOW_BRACKETS.iter().find(|(input, _)| *input == key) {
                self.last_alternating_quote = None;
                return Some(output);
            }
        }
        // 顿号键可被偏好关掉（enumerationComma 段）：没启用的键返回 `None`，按普通字符交回宿主。`\` 同时在 `SIMPLE` 里，由这段先拦下；`/` 不在 `SIMPLE`，启用了才出顿号。
        if let Some(&(input, output)) = ENUMERATION_COMMA.iter().find(|(input, _)| *input == key) {
            let enabled = match input {
                b'\\' => self.marks.enumeration_comma_backslash,
                _ => self.marks.enumeration_comma_slash,
            };
            self.last_alternating_quote = None;
            return enabled.then_some(output);
        }
        if let Some(&(_, output)) = SIMPLE.iter().find(|(input, _)| *input == key) {
            self.last_alternating_quote = None;
            return Some(output);
        }
        let corner = self.marks.quotes == QuoteMarks::Corner;
        if !matches!(key, b'"' | b'\'') {
            self.last_alternating_quote = None;
        }
        // Without host pairing this alternation is the only way to type a closing quote, and a host that does pair rewrites the closing quote itself, so it runs either way (punctuation_policy.cpp:12).
        // 交替状态按键保存，和出哪一组字无关：换样式不重置它。
        match key {
            b'"' => {
                self.last_alternating_quote = Some(key);
                Some(alternate(
                    &mut self.next_double_quote_is_opening,
                    if corner {
                        CORNER_DOUBLE_QUOTE
                    } else {
                        DOUBLE_QUOTE
                    },
                ))
            }
            b'\'' => {
                self.last_alternating_quote = Some(key);
                Some(alternate(
                    &mut self.next_single_quote_is_opening,
                    if corner {
                        CORNER_SINGLE_QUOTE
                    } else {
                        SINGLE_QUOTE
                    },
                ))
            }
            NESTED_OPENING_INPUT => {
                self.book_title_nesting += 1;
                Some(if self.book_title_nesting == 1 {
                    NESTED_OPENING
                } else {
                    NESTED_OPENING_INNER
                })
            }
            // An unmatched `>` leaves the count at zero, so the next `<` still opens the outer pair.
            NESTED_CLOSING_INPUT => {
                if self.book_title_nesting == 0 {
                    return Some(NESTED_CLOSING);
                }
                self.book_title_nesting -= 1;
                Some(if self.book_title_nesting == 0 {
                    NESTED_CLOSING
                } else {
                    NESTED_CLOSING_INNER
                })
            }
            _ => None,
        }
    }

    /// 记住一次非标点输入或编辑动作，使退格不会撤销更早的引号。
    pub fn clear_quote_undo(&mut self) {
        self.last_alternating_quote = None;
    }

    /// 撤销最近一次交替引号。宿主只在空闲退格确实删掉刚才的标点时调用。
    pub fn undo_last_quote(&mut self) {
        let Some(key) = self.last_alternating_quote.take() else {
            return;
        };
        match key {
            b'"' => self.next_double_quote_is_opening = !self.next_double_quote_is_opening,
            b'\'' => self.next_single_quote_is_opening = !self.next_single_quote_is_opening,
            _ => {}
        }
    }

    pub fn set_paired_enabled(&mut self, enabled: bool) {
        self.paired_enabled = enabled;
    }

    pub fn set_marks(&mut self, marks: PunctuationMarks) {
        self.marks = marks;
    }

    /// The host emitted the closing half of `opening` itself; only `<` with pairing on and a positive nesting count changes anything.
    pub fn balance_after_auto_close(&mut self, opening: u8) {
        if self.paired_enabled && opening == NESTED_OPENING_INPUT && self.book_title_nesting > 0 {
            self.book_title_nesting -= 1;
        }
    }
}

fn alternate(
    next_is_opening: &mut bool,
    (opening, closing): (&'static str, &'static str),
) -> &'static str {
    let output = if *next_is_opening { opening } else { closing };
    *next_is_opening = !*next_is_opening;
    output
}

#[cfg(test)]
mod tests {
    use super::*;

    fn translate_all(policy: &mut PunctuationPolicy, keys: &str) -> Vec<Option<&'static str>> {
        keys.bytes().map(|key| policy.translate(key)).collect()
    }

    /// The table is the one `shared/contracts/punctuation/policy.json` defines, and `policy.h`, which English-mode output on macOS, IBus and Fcitx5 reads, carries the same rows, so a key gives the same mark in either mode.
    #[test]
    fn matches_the_shared_contract() {
        let spec: serde_json::Value = serde_json::from_str(include_str!(
            "../../../shared/contracts/punctuation/policy.json"
        ))
        .expect("policy.json");
        assert_eq!(spec["contractVersion"], 5);
        let simple = spec["simple"].as_array().expect("simple");
        assert_eq!(simple.len(), SIMPLE.len());
        for ((input, output), row) in SIMPLE.iter().zip(simple) {
            assert_eq!(
                row["input"].as_str().map(str::as_bytes),
                Some(&[*input][..])
            );
            assert_eq!(row["output"], *output);
        }
        let alternating = spec["alternating"].as_array().expect("alternating");
        assert_eq!(alternating.len(), 2);
        for (row, (input, (opening, closing))) in alternating
            .iter()
            .zip([("\"", DOUBLE_QUOTE), ("'", SINGLE_QUOTE)])
        {
            assert_eq!(row["input"], input);
            assert_eq!(row["opening"], opening);
            assert_eq!(row["closing"], closing);
        }
        let nested = &spec["nested"];
        assert_eq!(
            nested["openingInput"].as_str().map(str::as_bytes),
            Some(&[NESTED_OPENING_INPUT][..])
        );
        assert_eq!(
            nested["closingInput"].as_str().map(str::as_bytes),
            Some(&[NESTED_CLOSING_INPUT][..])
        );
        assert_eq!(nested["opening"], NESTED_OPENING);
        assert_eq!(nested["nestedOpening"], NESTED_OPENING_INNER);
        assert_eq!(nested["closing"], NESTED_CLOSING);
        assert_eq!(nested["nestedClosing"], NESTED_CLOSING_INNER);

        let styles = &spec["styles"];
        let corner = styles["cornerQuotes"].as_array().expect("cornerQuotes");
        assert_eq!(corner.len(), 2);
        for (row, (input, (opening, closing))) in corner
            .iter()
            .zip([("\"", CORNER_DOUBLE_QUOTE), ("'", CORNER_SINGLE_QUOTE)])
        {
            assert_eq!(row["input"], input);
            assert_eq!(row["opening"], opening);
            assert_eq!(row["closing"], closing);
        }
        let hollow = styles["hollowBrackets"].as_array().expect("hollowBrackets");
        assert_eq!(hollow.len(), HOLLOW_BRACKETS.len());
        for ((input, output), row) in HOLLOW_BRACKETS.iter().zip(hollow) {
            assert_eq!(
                row["input"].as_str().map(str::as_bytes),
                Some(&[*input][..])
            );
            assert_eq!(row["output"], *output);
        }
        let enumeration = spec["enumerationComma"]
            .as_array()
            .expect("enumerationComma");
        assert_eq!(enumeration.len(), ENUMERATION_COMMA.len());
        for ((input, output), row) in ENUMERATION_COMMA.iter().zip(enumeration) {
            assert_eq!(
                row["input"].as_str().map(str::as_bytes),
                Some(&[*input][..])
            );
            assert_eq!(row["output"], *output);
        }

        let header = include_str!("../../../shared/contracts/punctuation/policy.h");
        let literal = |input: u8| match input {
            b'\\' => "'\\\\'".to_owned(),
            b'\'' => "'\\''".to_owned(),
            _ => format!("'{}'", input as char),
        };
        assert!(header.contains(&format!("std::array<Mapping, {}> simple", SIMPLE.len())));
        for (input, output) in SIMPLE {
            let row = format!("{{{}, \"{output}\"}}", literal(input));
            assert!(header.contains(&row), "policy.h lacks {row}");
        }
        for (input, (opening, closing)) in [
            (b'"', DOUBLE_QUOTE),
            (b'\'', SINGLE_QUOTE),
            (b'"', CORNER_DOUBLE_QUOTE),
            (b'\'', CORNER_SINGLE_QUOTE),
        ] {
            let row = format!("{{{}, \"{opening}\", \"{closing}\"}}", literal(input));
            assert!(header.contains(&row), "policy.h lacks {row}");
        }
        assert!(header.contains("std::array<AlternatingMapping, 2> alternating"));
        assert!(header.contains("std::array<AlternatingMapping, 2> corner_quotes"));
        assert!(header.contains(&format!(
            "std::array<Mapping, {}> hollow_brackets",
            HOLLOW_BRACKETS.len()
        )));
        for (input, output) in HOLLOW_BRACKETS {
            let row = format!("{{{}, \"{output}\"}}", literal(input));
            assert!(header.contains(&row), "policy.h lacks {row}");
        }
        assert!(header.contains(&format!(
            "std::array<Mapping, {}> enumeration_comma",
            ENUMERATION_COMMA.len()
        )));
        for (input, output) in ENUMERATION_COMMA {
            let row = format!("{{{}, \"{output}\"}}", literal(input));
            assert!(header.contains(&row), "policy.h lacks {row}");
        }
        for (name, value) in [
            ("nested_opening_input", literal(NESTED_OPENING_INPUT)),
            ("nested_closing_input", literal(NESTED_CLOSING_INPUT)),
            ("nested_opening[]", format!("\"{NESTED_OPENING}\"")),
            (
                "nested_opening_inner[]",
                format!("\"{NESTED_OPENING_INNER}\""),
            ),
            ("nested_closing[]", format!("\"{NESTED_CLOSING}\"")),
            (
                "nested_closing_inner[]",
                format!("\"{NESTED_CLOSING_INNER}\""),
            ),
        ] {
            let line = format!("{name} = {value};");
            assert!(header.contains(&line), "policy.h lacks {line}");
        }
    }

    /// contracts/tests/punctuation_contract.cpp.
    #[test]
    fn contract_table() {
        assert_eq!(SIMPLE.len(), 17);
        assert_eq!(ENUMERATION_COMMA.len(), 2);
        let mut policy = PunctuationPolicy::default();
        assert_eq!(policy.translate(b'$'), Some("￥"));
        assert_eq!(policy.translate(b'_'), Some("——"));
        assert_eq!(policy.translate(b'"'), Some("“"));
        assert_eq!(policy.translate(b'"'), Some("”"));
        assert_eq!(policy.translate(b'<'), Some("《"));
        assert_eq!(policy.translate(b'<'), Some("〈"));
        for key in *b"a@-1 /" {
            assert_eq!(policy.translate(key), None);
        }
    }

    /// 契约第 4 版：`enumerationComma` 的键由各自的偏好开关决定，没打开的键返回 `None`（宿主按普通字符输出）。缺省是「只有 `\`」，`/` 因此仍是命令模式触发键。
    #[test]
    fn enumeration_comma_keys_follow_their_switches() {
        let mut policy = PunctuationPolicy::default();
        assert_eq!(policy.translate(b'\\'), Some("、"));
        assert_eq!(policy.translate(b'/'), None);

        policy.set_marks(PunctuationMarks {
            enumeration_comma_slash: true,
            ..PunctuationMarks::default()
        });
        assert_eq!(policy.translate(b'/'), Some("、"));

        policy.set_marks(PunctuationMarks {
            enumeration_comma_backslash: false,
            enumeration_comma_slash: true,
            ..PunctuationMarks::default()
        });
        assert_eq!(policy.translate(b'\\'), None);
        assert_eq!(policy.translate(b'/'), Some("、"));

        // 两个都关时谁出顿号是偏好解析处的归一职责；引擎只照开关执行，两个都关就都按普通字符。
        policy.set_marks(PunctuationMarks {
            enumeration_comma_backslash: false,
            enumeration_comma_slash: false,
            ..PunctuationMarks::default()
        });
        assert_eq!(policy.translate(b'\\'), None);
        assert_eq!(policy.translate(b'/'), None);
        assert_eq!(policy.translate(b','), Some("，"));
    }

    /// The idle map of test_input_session.cpp:850-885, as recorded in the qp_idle_chinese_punctuation golden.
    #[test]
    fn idle_map_in_recorded_order() {
        let mut policy = PunctuationPolicy::default();
        let expected = [
            "。", "“", "”", "‘", "’", "（", "）", "【", "】", "·", "￥", "……", "——", "《", "〈",
            "〉", "》", "、",
        ];
        let actual = translate_all(&mut policy, ".\"\"''()[]`$^_<<>>\\");
        assert_eq!(actual, expected.map(Some));
        let rest = translate_all(&mut policy, ",?!;:");
        assert_eq!(rest, ["，", "？", "！", "；", "："].map(Some));
    }

    #[test]
    fn quotes_toggle_independently() {
        let mut policy = PunctuationPolicy::default();
        assert_eq!(
            translate_all(&mut policy, "\"'\"'"),
            ["“", "‘", "”", "’"].map(Some)
        );
    }

    #[test]
    fn deleting_the_last_quote_restores_its_direction() {
        let mut policy = PunctuationPolicy::default();
        assert_eq!(policy.translate(b'"'), Some("“"));
        policy.undo_last_quote();
        assert_eq!(policy.translate(b'"'), Some("“"));

        // 其他标点会结束撤销窗口；这是正常的引号交替，删除后面的字符不能重新打开它。
        assert_eq!(policy.translate(b':'), Some("："));
        policy.undo_last_quote();
        assert_eq!(policy.translate(b'"'), Some("”"));
    }

    /// qp_paired_punctuation_disabled: alternation and nesting run with pairing off, and toggling pairing resets neither.
    #[test]
    fn pairing_off_still_alternates_and_nests() {
        let mut policy = PunctuationPolicy::default();
        policy.set_paired_enabled(false);
        assert_eq!(
            translate_all(&mut policy, "\"\"''<<>>"),
            ["“", "”", "‘", "’", "《", "〈", "〉", "》"].map(Some)
        );
        policy.translate(b'"');
        policy.set_paired_enabled(true);
        assert_eq!(policy.translate(b'"'), Some("”"));
    }

    #[test]
    fn unmatched_closing_never_goes_negative() {
        let mut policy = PunctuationPolicy::default();
        assert_eq!(
            translate_all(&mut policy, ">><"),
            ["》", "》", "《"].map(Some)
        );
        assert_eq!(policy.book_title_nesting, 1);
    }

    #[test]
    fn auto_close_balances_only_with_pairing() {
        let mut policy = PunctuationPolicy::default();
        assert_eq!(policy.translate(b'<'), Some("《"));
        policy.balance_after_auto_close(b'<');
        assert_eq!(policy.book_title_nesting, 0);
        assert_eq!(policy.translate(b'<'), Some("《"));

        policy.balance_after_auto_close(b'(');
        assert_eq!(policy.book_title_nesting, 1);

        policy.set_paired_enabled(false);
        policy.balance_after_auto_close(b'<');
        assert_eq!(policy.book_title_nesting, 1);
        assert_eq!(policy.translate(b'<'), Some("〈"));

        policy.set_paired_enabled(true);
        let mut empty = PunctuationPolicy::default();
        empty.balance_after_auto_close(b'<');
        assert_eq!(empty.book_title_nesting, 0);
    }

    fn styled(quotes: QuoteMarks, brackets: BracketMarks) -> PunctuationPolicy {
        let mut policy = PunctuationPolicy::default();
        policy.set_marks(PunctuationMarks {
            quotes,
            brackets,
            ..PunctuationMarks::default()
        });
        policy
    }

    #[test]
    fn corner_quotes_alternate_per_key() {
        let mut policy = styled(QuoteMarks::Corner, BracketMarks::Solid);
        assert_eq!(
            translate_all(&mut policy, "'\"'\""),
            ["「", "『", "」", "』"].map(Some)
        );
        assert_eq!(translate_all(&mut policy, "[]"), ["【", "】"].map(Some));
    }

    #[test]
    fn hollow_brackets_replace_only_square_keys() {
        let mut hollow = styled(QuoteMarks::Curly, BracketMarks::Hollow);
        let mut solid = PunctuationPolicy::default();
        assert_eq!(translate_all(&mut hollow, "[]"), ["〖", "〗"].map(Some));
        for (key, _) in SIMPLE.iter().filter(|(key, _)| !matches!(key, b'[' | b']')) {
            assert_eq!(hollow.translate(*key), solid.translate(*key));
        }
        assert_eq!(
            translate_all(&mut hollow, "\"'<>"),
            ["“", "‘", "《", "》"].map(Some)
        );
    }

    /// 契约第 5 版（#10047）：`Shift+[` `Shift+]`（`{` `}`）固定出左右直角引号「」，不交替，不随引号样式和成对开关变，也不动 `'` `"` 的交替状态。
    #[test]
    fn shifted_brackets_give_corner_quotes() {
        let mut policy = PunctuationPolicy::default();
        assert_eq!(
            translate_all(&mut policy, "{}{{}}"),
            ["「", "」", "「", "「", "」", "」"].map(Some)
        );
        // 两个弯引号键从没按过，仍出前半个。
        assert_eq!(
            translate_all(&mut policy, "\"'}{"),
            ["“", "‘", "」", "「"].map(Some)
        );
        // 直角引号样式下 `{` `}` 出的还是这两个字：样式只换 `'` `"` 的字，`'` 的交替也不受 `{` `}` 影响。
        let mut corner = styled(QuoteMarks::Corner, BracketMarks::Hollow);
        assert_eq!(
            translate_all(&mut corner, "{'}'"),
            ["「", "「", "」", "」"].map(Some)
        );
        // 成对补全关着也一样。
        policy.set_paired_enabled(false);
        assert_eq!(translate_all(&mut policy, "}{"), ["」", "「"].map(Some));
        // 固定映射不是交替引号：退格撤销不碰它，也不撤销更早的引号。
        assert_eq!(policy.translate(b'"'), Some("”"));
        assert_eq!(policy.translate(b'{'), Some("「"));
        policy.undo_last_quote();
        assert_eq!(policy.translate(b'"'), Some("“"));
    }

    /// 缺省样式就是契约第 1 版那张表，逐键相同。
    #[test]
    fn default_marks_match_the_contract() {
        assert_eq!(
            PunctuationMarks::default(),
            PunctuationMarks {
                quotes: QuoteMarks::Curly,
                brackets: BracketMarks::Solid,
                enumeration_comma_backslash: true,
                enumeration_comma_slash: false,
            }
        );
        let mut styled = styled(QuoteMarks::Curly, BracketMarks::Solid);
        let mut default = PunctuationPolicy::default();
        let keys = ",.?!;:()[]\\`$^_\"\"''<<>>";
        assert_eq!(
            translate_all(&mut styled, keys),
            translate_all(&mut default, keys)
        );
    }

    #[test]
    fn marks_do_not_reset_alternation() {
        let mut policy = PunctuationPolicy::default();
        assert_eq!(policy.translate(b'\''), Some("‘"));
        policy.set_marks(PunctuationMarks {
            quotes: QuoteMarks::Corner,
            brackets: BracketMarks::Solid,
            ..PunctuationMarks::default()
        });
        assert_eq!(policy.translate(b'\''), Some("」"));
        assert_eq!(policy.translate(b'\''), Some("「"));
    }

    #[test]
    fn pairing_off_still_alternates_corner_quotes() {
        let mut policy = styled(QuoteMarks::Corner, BracketMarks::Hollow);
        policy.set_paired_enabled(false);
        assert_eq!(
            translate_all(&mut policy, "''\"\"[]"),
            ["「", "」", "『", "』", "〖", "〗"].map(Some)
        );
    }

    #[test]
    fn balance_after_auto_close_ignores_styles() {
        let mut policy = styled(QuoteMarks::Corner, BracketMarks::Hollow);
        assert_eq!(policy.translate(b'<'), Some("《"));
        policy.balance_after_auto_close(b'[');
        policy.balance_after_auto_close(b'\'');
        assert_eq!(policy.book_title_nesting, 1);
        policy.balance_after_auto_close(b'<');
        assert_eq!(policy.book_title_nesting, 0);
        assert_eq!(policy.translate(b'\''), Some("「"));
    }
}