2023-09-25 16:19:22 +02:00

368 lines
11 KiB
Rust
Raw Blame History

This file contains ambiguous Unicode characters

This file contains Unicode characters that might be confused with other characters. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

use typst::syntax::is_newline;
use unicode_segmentation::UnicodeSegmentation;
use crate::prelude::*;
/// A language-aware quote that reacts to its context.
///
/// Automatically turns into an appropriate opening or closing quote based on
/// the active [text language]($text.lang).
///
/// # Example
/// ```example
/// "This is in quotes."
///
/// #set text(lang: "de")
/// "Das ist in Anführungszeichen."
///
/// #set text(lang: "fr")
/// "C'est entre guillemets."
/// ```
///
/// # Syntax
/// This function also has dedicated syntax: The normal quote characters
/// (`'` and `"`). Typst automatically makes your quotes smart.
#[elem]
pub struct SmartquoteElem {
/// Whether this should be a double quote.
#[default(true)]
pub double: bool,
/// Whether smart quotes are enabled.
///
/// To disable smartness for a single quote, you can also escape it with a
/// backslash.
///
/// ```example
/// #set smartquote(enabled: false)
///
/// These are "dumb" quotes.
/// ```
#[default(true)]
pub enabled: bool,
/// Whether to use alternative quotes.
///
/// Does nothing for languages that don't have alternative quotes, or if
/// explicit quotes were set.
///
/// ```example
/// #set text(lang: "de")
/// #set smartquote(alternative: true)
///
/// "Das ist in anderen Anführungszeichen."
/// ```
#[default(false)]
pub alternative: bool,
/// The quotes to use.
///
/// - When set to `{auto}`, the appropriate single quotes for the
/// [text language]($text.lang) will be used. This is the default.
/// - Custom quotes can be passed as a string, array, or dictionary of either
/// - [string]($str): a string consisting of two characters containing the
/// opening and closing double quotes (characters here refer to Unicode
/// grapheme clusters)
/// - [array]($array): an array containing the opening and closing double
/// quotes
/// - [dictionary]($dictionary): an array containing the double and single
/// quotes, each specified as either `{auto}`, string, or array
///
/// ```example
/// #set text(lang: "de")
/// 'Das sind normale Anführungszeichen.'
///
/// #set smartquote(quotes: "()")
/// "Das sind eigene Anführungszeichen."
///
/// #set smartquote(quotes: (single: ("[[", "]]"), double: auto))
/// 'Das sind eigene Anführungszeichen.'
/// ```
pub quotes: Smart<QuoteDict>,
}
/// State machine for smart quote substitution.
#[derive(Debug, Clone)]
pub struct Quoter {
/// How many quotes have been opened.
quote_depth: usize,
/// Whether an opening quote might follow.
expect_opening: bool,
/// Whether the last character was numeric.
last_num: bool,
/// The previous type of quote character, if it was an opening quote.
prev_quote_type: Option<bool>,
}
impl Quoter {
/// Start quoting.
pub fn new() -> Self {
Self {
quote_depth: 0,
expect_opening: true,
last_num: false,
prev_quote_type: None,
}
}
/// Process the last seen character.
pub fn last(&mut self, c: char, is_quote: bool) {
self.expect_opening = is_ignorable(c) || is_opening_bracket(c);
self.last_num = c.is_numeric();
if !is_quote {
self.prev_quote_type = None;
}
}
/// Process and substitute a quote.
pub fn quote<'a>(
&mut self,
quotes: &Quotes<'a>,
double: bool,
peeked: Option<char>,
) -> &'a str {
let peeked = peeked.unwrap_or(' ');
let mut expect_opening = self.expect_opening;
if let Some(prev_double) = self.prev_quote_type.take() {
if double != prev_double {
expect_opening = true;
}
}
if expect_opening {
self.quote_depth += 1;
self.prev_quote_type = Some(double);
quotes.open(double)
} else if self.quote_depth > 0
&& (peeked.is_ascii_punctuation() || is_ignorable(peeked))
{
self.quote_depth -= 1;
quotes.close(double)
} else if self.last_num {
quotes.prime(double)
} else {
quotes.fallback(double)
}
}
}
impl Default for Quoter {
fn default() -> Self {
Self::new()
}
}
fn is_ignorable(c: char) -> bool {
c.is_whitespace() || is_newline(c)
}
fn is_opening_bracket(c: char) -> bool {
matches!(c, '(' | '{' | '[')
}
/// Decides which quotes to substitute smart quotes with.
pub struct Quotes<'s> {
/// The opening single quote.
pub single_open: &'s str,
/// The closing single quote.
pub single_close: &'s str,
/// The opening double quote.
pub double_open: &'s str,
/// The closing double quote.
pub double_close: &'s str,
}
impl<'s> Quotes<'s> {
/// Create a new `Quotes` struct with the given quotes, optionally falling
/// back to the defaults for a language and region.
///
/// The language should be specified as an all-lowercase ISO 639-1 code, the
/// region as an all-uppercase ISO 3166-alpha2 code.
///
/// Currently, the supported languages are: English, Czech, Danish, German,
/// Swiss / Liechtensteinian German, Estonian, Icelandic, Lithuanian,
/// Latvian, Slovak, Slovenian, Spanish, Bosnian, Finnish, Swedish, French,
/// Hungarian, Polish, Romanian, Japanese, Traditional Chinese, Russian, and
/// Norwegian.
///
/// For unknown languages, the English quotes are used as fallback.
pub fn new(
quotes: &'s Smart<QuoteDict>,
lang: Lang,
region: Option<Region>,
alternative: bool,
) -> Self {
let region = region.as_ref().map(Region::as_str);
let default = ("", "", "", "");
let low_high = ("", "", "", "");
let (single_open, single_close, double_open, double_close) = match lang.as_str() {
"de" if matches!(region, Some("CH" | "LI")) => match alternative {
false => ("", "", "«", "»"),
true => low_high,
},
"cs" | "da" | "de" | "sk" | "sl" if alternative => ("", "", "»", "«"),
"cs" | "da" | "de" | "et" | "is" | "lt" | "lv" | "sk" | "sl" => low_high,
"fr" | "ru" if alternative => default,
"fr" => ("\u{00A0}", "\u{00A0}", "«\u{00A0}", "\u{00A0}»"),
"fi" | "sv" if alternative => ("", "", "»", "»"),
"bs" | "fi" | "sv" => ("", "", "", ""),
"es" if matches!(region, Some("ES") | None) => ("", "", "«", "»"),
"hu" | "pl" | "ro" => ("", "", "", ""),
"no" | "nb" | "nn" if alternative => low_high,
"ru" | "no" | "nb" | "nn" | "ua" => ("", "", "«", "»"),
_ if lang.dir() == Dir::RTL => ("", "", "", ""),
_ => default,
};
fn inner_or_default<'s>(
quotes: Smart<&'s QuoteDict>,
f: impl FnOnce(&'s QuoteDict) -> Smart<&'s QuoteSet>,
default: [&'s str; 2],
) -> [&'s str; 2] {
match quotes.and_then(f) {
Smart::Auto => default,
Smart::Custom(QuoteSet { open, close }) => {
[open, close].map(|s| s.as_str())
}
}
}
let quotes = quotes.as_ref();
let [single_open, single_close] =
inner_or_default(quotes, |q| q.single.as_ref(), [single_open, single_close]);
let [double_open, double_close] =
inner_or_default(quotes, |q| q.double.as_ref(), [double_open, double_close]);
Self {
single_open,
single_close,
double_open,
double_close,
}
}
/// The opening quote.
fn open(&self, double: bool) -> &'s str {
if double {
self.double_open
} else {
self.single_open
}
}
/// The closing quote.
fn close(&self, double: bool) -> &'s str {
if double {
self.double_close
} else {
self.single_close
}
}
/// Which character should be used as a prime.
fn prime(&self, double: bool) -> &'static str {
if double {
""
} else {
""
}
}
/// Which character should be used as a fallback quote.
fn fallback(&self, double: bool) -> &'static str {
if double {
"\""
} else {
""
}
}
}
/// An opening and closing quote.
#[derive(Debug, Clone, Eq, PartialEq, Hash)]
pub struct QuoteSet {
open: EcoString,
close: EcoString,
}
cast! {
QuoteSet,
self => array![self.open, self.close].into_value(),
value: Array => {
let [open, close] = array_to_set(value)?;
Self { open, close }
},
value: Str => {
let [open, close] = str_to_set(value.as_str())?;
Self { open, close }
},
}
fn str_to_set(value: &str) -> StrResult<[EcoString; 2]> {
let mut iter = value.graphemes(true);
match (iter.next(), iter.next(), iter.next()) {
(Some(open), Some(close), None) => Ok([open.into(), close.into()]),
_ => {
let count = value.graphemes(true).count();
bail!(
"expected 2 characters, found {count} character{}",
if count > 1 { "s" } else { "" }
);
}
}
}
fn array_to_set(value: Array) -> StrResult<[EcoString; 2]> {
let value = value.as_slice();
if value.len() != 2 {
bail!(
"expected 2 quotes, found {} quote{}",
value.len(),
if value.len() > 1 { "s" } else { "" }
);
}
let open: EcoString = value[0].clone().cast()?;
let close: EcoString = value[1].clone().cast()?;
Ok([open, close])
}
/// A dict of single and double quotes.
#[derive(Debug, Clone, Eq, PartialEq, Hash)]
pub struct QuoteDict {
double: Smart<QuoteSet>,
single: Smart<QuoteSet>,
}
cast! {
QuoteDict,
self => dict! { "double" => self.double, "single" => self.single }.into_value(),
mut value: Dict => {
let keys = ["double", "single"];
let double = value
.take("double")
.ok()
.map(FromValue::from_value)
.transpose()?
.unwrap_or(Smart::Auto);
let single = value
.take("single")
.ok()
.map(FromValue::from_value)
.transpose()?
.unwrap_or(Smart::Auto);
value.finish(&keys)?;
Self { single, double }
},
value: QuoteSet => Self {
double: Smart::Custom(value),
single: Smart::Auto,
},
}