Add start parameter to array enumerate (#1818)

2 files changed, 14 insertions, 3 deletions

diff --git a/crates/typst/src/eval/array.rs b/crates/typst/src/eval/array.rs
index 5d5fdcdb..86c41ff6 100644
--- a/crates/typst/src/eval/array.rs
+++ b/crates/typst/src/eval/array.rs
@@ -392,10 +392,18 @@ impl Array {
     }
 
     /// Enumerate all items in the array.
-    pub fn enumerate(&self) -> Self {
+    pub fn enumerate(&self, start: i64) -> StrResult<Self> {
         self.iter()
             .enumerate()
-            .map(|(i, value)| array![i, value.clone()].into_value())
+            .map(|(i, value)| {
+                Ok(array![
+                    start
+                        .checked_add_unsigned(i as u64)
+                        .ok_or_else(|| "array index is too large".to_string())?,
+                    value.clone()
+                ]
+                .into_value())
+            })
             .collect()
     }
 
diff --git a/crates/typst/src/eval/methods.rs b/crates/typst/src/eval/methods.rs
index bf47b7aa..6a846f52 100644
--- a/crates/typst/src/eval/methods.rs
+++ b/crates/typst/src/eval/methods.rs
@@ -146,7 +146,10 @@ pub fn call(
             }
             "sorted" => array.sorted(vm, span, args.named("key")?)?.into_value(),
             "zip" => array.zip(args.expect("other")?).into_value(),
-            "enumerate" => array.enumerate().into_value(),
+            "enumerate" => array
+                .enumerate(args.named("start")?.unwrap_or(0))
+                .at(span)?
+                .into_value(),
             "dedup" => array.dedup(vm, args.named("key")?)?.into_value(),
             _ => return missing(),
         },