Make language non-optional with english as default

3 files changed, 48 insertions, 41 deletions

diff --git a/src/library/text/lang.rs b/src/library/text/lang.rs
new file mode 100644
index 00000000..343359d1
--- /dev/null
+++ b/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")?,
+}
diff --git a/src/library/text/mod.rs b/src/library/text/mod.rs
index a25b2827..636b878c 100644
--- a/src/library/text/mod.rs
+++ b/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,
         }
     }
diff --git a/src/library/text/par.rs b/src/library/text/par.rs
index 19ab1082..232a5d0f 100644
--- a/src/library/text/par.rs
+++ b/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()?;