Split out four new crates (#5302)

1 files changed, 79 insertions, 0 deletions

diff --git a/crates/typst-library/src/text/case.rs b/crates/typst-library/src/text/case.rs
new file mode 100644
index 00000000..69dbf5e1
--- /dev/null
+++ b/crates/typst-library/src/text/case.rs
@@ -0,0 +1,79 @@
+use crate::foundations::{cast, func, Cast, Content, Str};
+use crate::text::TextElem;
+
+/// Converts a string or content to lowercase.
+///
+/// # Example
+/// ```example
+/// #lower("ABC") \
+/// #lower[*My Text*] \
+/// #lower[already low]
+/// ```
+#[func(title = "Lowercase")]
+pub fn lower(
+    /// The text to convert to lowercase.
+    text: Caseable,
+) -> Caseable {
+    case(text, Case::Lower)
+}
+
+/// Converts a string or content to uppercase.
+///
+/// # Example
+/// ```example
+/// #upper("abc") \
+/// #upper[*my text*] \
+/// #upper[ALREADY HIGH]
+/// ```
+#[func(title = "Uppercase")]
+pub fn upper(
+    /// The text to convert to uppercase.
+    text: Caseable,
+) -> Caseable {
+    case(text, Case::Upper)
+}
+
+/// Change the case of text.
+fn case(text: Caseable, case: Case) -> Caseable {
+    match text {
+        Caseable::Str(v) => Caseable::Str(case.apply(&v).into()),
+        Caseable::Content(v) => {
+            Caseable::Content(v.styled(TextElem::set_case(Some(case))))
+        }
+    }
+}
+
+/// A value whose case can be changed.
+pub enum Caseable {
+    Str(Str),
+    Content(Content),
+}
+
+cast! {
+    Caseable,
+    self => match self {
+        Self::Str(v) => v.into_value(),
+        Self::Content(v) => v.into_value(),
+    },
+    v: Str => Self::Str(v),
+    v: Content => Self::Content(v),
+}
+
+/// A case transformation on text.
+#[derive(Debug, Copy, Clone, Eq, PartialEq, Hash, Cast)]
+pub enum Case {
+    /// Everything is lowercased.
+    Lower,
+    /// Everything is uppercased.
+    Upper,
+}
+
+impl Case {
+    /// Apply the case to a string.
+    pub fn apply(self, text: &str) -> String {
+        match self {
+            Self::Lower => text.to_lowercase(),
+            Self::Upper => text.to_uppercase(),
+        }
+    }
+}