From d8ee74f5d31c0ecfba08d375a4d5229776032eac Mon Sep 17 00:00:00 2001
From: Malo <57839069+MDLC01@users.noreply.github.com>
Date: Thu, 3 Jul 2025 22:47:11 +0100
Subject: [PATCH] Add `default` argument for `str.first` and `str.last`

---
 crates/typst-library/src/foundations/str.rs | 26 ++++++++++++++++-----
 1 file changed, 20 insertions(+), 6 deletions(-)

diff --git a/crates/typst-library/src/foundations/str.rs b/crates/typst-library/src/foundations/str.rs
index 23a1bd4cf..015716b94 100644
--- a/crates/typst-library/src/foundations/str.rs
+++ b/crates/typst-library/src/foundations/str.rs
@@ -178,25 +178,39 @@ impl Str {
         self.0.len()
     }
 
-    /// Extracts the first grapheme cluster of the string.
-    /// Fails with an error if the string is empty.
+    /// Extracts the first grapheme cluster of the string. Fails with an error
+    /// if the string is empty. Returns the default value if the string is empty
+    /// or fails with an error is no default value was specified.
     #[func]
-    pub fn first(&self) -> StrResult<Str> {
+    pub fn first(
+        &self,
+        /// A default value to return if the string is empty.
+        #[named]
+        default: Option<Str>,
+    ) -> StrResult<Str> {
         self.0
             .graphemes(true)
             .next()
             .map(Into::into)
+            .or(default)
             .ok_or_else(string_is_empty)
     }
 
-    /// Extracts the last grapheme cluster of the string.
-    /// Fails with an error if the string is empty.
+    /// Extracts the last grapheme cluster of the string. Fails with an error if
+    /// the string is empty. Returns the default value if the string is empty or
+    /// fails with an error is no default value was specified.
     #[func]
-    pub fn last(&self) -> StrResult<Str> {
+    pub fn last(
+        &self,
+        /// A default value to return if the string is empty.
+        #[named]
+        default: Option<Str>,
+    ) -> StrResult<Str> {
         self.0
             .graphemes(true)
             .next_back()
             .map(Into::into)
+            .or(default)
             .ok_or_else(string_is_empty)
     }