Make language non-optional with english as default

src/library/text/lang.rs

@@ -0,0 +1,39 @@
+use crate::eval::Value;
+use crate::geom::Dir;
+
+/// A natural language.
+#[derive(Debug, Copy, Clone, Eq, PartialEq, Ord, PartialOrd, Hash)]
+pub struct Lang([u8; 2]);
+
+impl Lang {
+    /// The code for the english language.
+    pub const ENGLISH: Self = Self(*b"en");
+
+    /// Construct a language from a two-byte ISO 639-1 code.
+    pub fn from_str(iso: &str) -> Option<Self> {
+        let mut bytes: [u8; 2] = iso.as_bytes().try_into().ok()?;
+        bytes.make_ascii_lowercase();
+        Some(Self(bytes))
+    }
+
+    /// Return the language code as a string slice.
+    pub fn as_str(&self) -> &str {
+        std::str::from_utf8(&self.0).unwrap_or_default()
+    }
+
+    /// The default direction for the language.
+    pub fn dir(&self) -> Dir {
+        match self.as_str() {
+            "ar" | "dv" | "fa" | "he" | "ks" | "pa" | "ps" | "sd" | "ug" | "ur"
+            | "yi" => Dir::RTL,
+            _ => Dir::LTR,
+        }
+    }
+}
+
+castable! {
+    Lang,
+    Expected: "string",
+    Value::Str(string) => Self::from_str(&string)
+        .ok_or("expected two letter language code")?,
+}

src/library/text/mod.rs

@@ -1,6 +1,7 @@
 //! Text handling and paragraph layout.
 
 mod deco;
+mod lang;
 mod link;
 mod par;
 mod quotes;
@@ -8,6 +9,7 @@ mod raw;
 mod shaping;
 
 pub use deco::*;
+pub use lang::*;
 pub use link::*;
 pub use par::*;
 pub use quotes::*;
@@ -64,8 +66,7 @@ impl TextNode {
     pub const BOTTOM_EDGE: TextEdge = TextEdge::Metric(VerticalFontMetric::Baseline);
 
     /// An ISO 639-1 language code.
-    #[property(referenced)]
-    pub const LANG: Option<Lang> = None;
+    pub const LANG: Lang = Lang::ENGLISH;
     /// The direction for text and inline objects. When `auto`, the direction is
     /// automatically inferred from the language.
     #[property(resolve)]
@@ -257,32 +258,6 @@ castable! {
     }),
 }
 
-/// A natural language.
-#[derive(Debug, Clone, Eq, PartialEq, Hash)]
-pub struct Lang(EcoString);
-
-impl Lang {
-    /// The default direction for the language.
-    pub fn dir(&self) -> Dir {
-        match self.0.as_str() {
-            "ar" | "dv" | "fa" | "he" | "ks" | "pa" | "ps" | "sd" | "ug" | "ur"
-            | "yi" => Dir::RTL,
-            _ => Dir::LTR,
-        }
-    }
-
-    /// Return the language code as a string slice.
-    pub fn as_str(&self) -> &str {
-        &self.0
-    }
-}
-
-castable! {
-    Lang,
-    Expected: "string",
-    Value::Str(string) => Self(string.to_lowercase()),
-}
-
 /// The direction of text and inline objects in their line.
 #[derive(Debug, Copy, Clone, Eq, PartialEq, Hash)]
 pub struct HorizontalDir(pub Dir);
@@ -301,10 +276,7 @@ impl Resolve for Smart<HorizontalDir> {
 
     fn resolve(self, styles: StyleChain) -> Self::Output {
         match self {
-            Smart::Auto => match styles.get(TextNode::LANG) {
-                Some(lang) => lang.dir(),
-                None => Dir::LTR,
-            },
+            Smart::Auto => styles.get(TextNode::LANG).dir(),
             Smart::Custom(dir) => dir.0,
         }
     }

src/library/text/par.rs

@@ -408,11 +408,7 @@ fn collect<'a>(
                 if styles.get(TextNode::SMART_QUOTES) {
                     // TODO: Also get region.
                     let lang = styles.get(TextNode::LANG);
-                    let quotes = lang
-                        .as_ref()
-                        .map(|lang| Quotes::from_lang(lang.as_str(), ""))
-                        .unwrap_or_default();
-
+                    let quotes = Quotes::from_lang(lang.as_str(), "");
                     let peeked = iter.peek().and_then(|(child, _)| match child {
                         ParChild::Text(text) => text.chars().next(),
                         ParChild::Quote(_) => Some('"'),
@@ -750,7 +746,7 @@ fn breakpoints<'a>(p: &'a Preparation) -> Breakpoints<'a> {
         end: 0,
         mandatory: false,
         hyphenate: p.get_shared(TextNode::HYPHENATE),
-        lang: p.get_shared(TextNode::LANG).map(Option::as_ref),
+        lang: p.get_shared(TextNode::LANG),
     }
 }
 
@@ -773,7 +769,7 @@ struct Breakpoints<'a> {
     /// Whether to hyphenate if it's the same for all children.
     hyphenate: Option<bool>,
     /// The text language if it's the same for all children.
-    lang: Option<Option<&'a Lang>>,
+    lang: Option<Lang>,
 }
 
 impl Iterator for Breakpoints<'_> {
@@ -831,9 +827,9 @@ impl Breakpoints<'_> {
 
     /// The text language at the given offset.
     fn lang_at(&self, offset: usize) -> Option<hypher::Lang> {
-        let lang = self.lang.unwrap_or_else(|| {
+        let lang = self.lang.or_else(|| {
             let shaped = self.p.find(offset)?.text()?;
-            shaped.styles.get(TextNode::LANG).as_ref()
+            Some(shaped.styles.get(TextNode::LANG))
         })?;
 
         let bytes = lang.as_str().as_bytes().try_into().ok()?;

tests/typ/text/hyphenate.typ

@@ -6,13 +6,13 @@
 #set page(width: auto)
 #grid(
   columns: (70pt, 60pt),
-  text(lang: "en")[Warm welcomes to Typst.],
+  [Warm welcomes to Typst.],
   text(lang: "el")[διαμερίσματα. \ λατρευτός],
 )
 
 ---
 // Test disabling hyphenation for short passages.
-#set text(lang: "en", hyphenate: true)
+#set text(hyphenate: true)
 
 Welcome to wonderful experiences. \
 Welcome to `wonderful` experiences. \
@@ -20,14 +20,14 @@ Welcome to #text(hyphenate: false)[wonderful] experiences. \
 Welcome to wonde#text(hyphenate: false)[rf]ul experiences. \
 
 // Test enabling hyphenation for short passages.
-#set text(lang: "en", hyphenate: false)
+#set text(hyphenate: false)
 Welcome to wonderful experiences. \
 Welcome to wo#text(hyphenate: true)[nd]erful experiences. \
 
 ---
 // Hyphenate between shape runs.
 #set page(width: 80pt)
-#set text(lang: "en", hyphenate: true)
+#set text(hyphenate: true)
 It's a #emph[Tree]beard.
 
 ---
@@ -46,5 +46,5 @@ It's a #emph[Tree]beard.
 // do that. The test passes if there's just one hyphenation between
 // "net" and "works".
 #set page(width: 70pt)
-#set text(lang: "en", hyphenate: true)
+#set text(hyphenate: true)
 #h(6pt) networks, the rest.

tests/typ/text/justify.typ

@@ -1,7 +1,6 @@
 
 ---
 #set page(width: 180pt)
-#set text(lang: "en")
 #set par(
   justify: true,
   indent: 14pt,

tests/typ/text/knuth.typ

@@ -1,6 +1,6 @@
 #set page(width: auto, height: auto)
 #set par(leading: 4pt, justify: true)
-#set text(lang: "en", family: "Latin Modern Roman")
+#set text(family: "Latin Modern Roman")
 
 #let story = [
   In olden times when wishing still helped one, there lived a king whose

tests/typ/text/microtype.typ

@@ -4,7 +4,7 @@
 // Test hanging punctuation.
 #set page(width: 130pt, margins: 15pt)
 #set par(justify: true, linebreaks: "simple")
-#set text(lang: "en", size: 9pt)
+#set text(size: 9pt)
 #rect(fill: rgb(repr(teal) + "00"), width: 100%)[
   This is a little bit of text that builds up to
   hang-ing hyphens and dash---es and then, you know,

tests/typ/text/quotes.typ

@@ -24,12 +24,10 @@
 
 ---
 // Test single pair of quotes.
-#set text(lang: "en")
 ""
 
 ---
 // Test sentences with numbers and apostrophes.
-#set text(lang: "en")
 The 5'11" 'quick' brown fox jumps over the "lazy" dog's ear.
 
 He said "I'm a big fella."
@@ -40,7 +38,6 @@ The 5\'11\" 'quick\' brown fox jumps over the \"lazy" dog\'s ear.
 
 ---
 // Test turning smart quotes off.
-#set text(lang: "en")
 He's told some books contain questionable "example text".
 
 #set text(smart-quotes: false)
@@ -48,7 +45,6 @@ He's told some books contain questionable "example text".
 
 ---
 // Test changing properties within text.
-#set text(lang: "en")
 "She suddenly started speaking french: #text(lang: "fr")['Je suis une banane.']" Roman told me.
 
 Some people's thought on this would be #text(smart-quotes: false)["strange."]