Add array.repeat

crates/typst/src/eval/ops.rs

@@ -329,8 +329,8 @@ pub fn mul(lhs: Value, rhs: Value) -> StrResult<Value> {
 
  (Str(a), Int(b)) => Str(a.repeat(Value::Int(b).cast()?)?),
  (Int(a), Str(b)) => Str(b.repeat(Value::Int(a).cast()?)?),
- (Array(a), Int(b)) => Array(a.repeat(Value::Int(b).cast()?)?),
- (Int(a), Array(b)) => Array(b.repeat(Value::Int(a).cast()?)?),
+ (Array(a), Int(b)) => Array(a.repeat_content(Value::Int(b).cast()?)?),
+ (Int(a), Array(b)) => Array(b.repeat_content(Value::Int(a).cast()?)?),
  (Content(a), b @ Int(_)) => Content(a.repeat(b.cast()?)),
  (a @ Int(_), Content(b)) => Content(b.repeat(a.cast()?)),
 

crates/typst/src/foundations/array.rs

@@ -1,5 +1,6 @@
 use std::cmp::Ordering;
 use std::fmt::{Debug, Formatter};
+use std::iter;
 use std::num::{NonZeroI64, NonZeroUsize};
 use std::ops::{Add, AddAssign};
 
@@ -135,8 +136,9 @@ impl Array {
  .filter(|&v| v < self.0.len() + end_ok as usize)
  }
 
- /// Repeat this array `n` times.
- pub fn repeat(&self, n: usize) -> StrResult<Self> {
+ /// Repeat the content of this array `n` times, that is, creates an
+ /// array that contains elements of the original array repeated n times.
+ pub fn repeat_content(&self, n: usize) -> StrResult<Self> {
  let count = self
  .len()
  .checked_mul(n)
@@ -882,6 +884,24 @@ impl Array {
  })
  .collect()
  }
+
+ /// Builds an array of a given value a given number of times.
+ ///
+ /// ```example
+ /// array.repeat("apples", 2)
+ /// ```
+ #[func]
+ pub fn repeat(
+ /// The value that will be repeated to build the array.
+ value: Value,
+ /// Length of the array. Must be positive.
+ times: i64,
+ ) -> StrResult<Array> {
+ match usize::try_from(times) {
+ Ok(times) => Ok(iter::repeat(value).take(times).collect()),
+ _ => Err(format!("Cannot create array with the length: {times}").into()),
+ }
+ }
 }
 
 /// A value that can be cast to bytes.

tests/suite/foundations/array.typ

@@ -492,3 +492,16 @@
 --- array-unclosed ---
 // Error: 3-4 unclosed delimiter
 #{(}
+
+--- array-repeat ---
+// Test the `join` method.
+#test(().repeat(2), ((), ()))
+#test((1,).repeat(3), ((1,), (1,), (1,)))
+#test(array.repeat("a", 4), ("a", "a", "a", "a"))
+#test(array.repeat(5, 0), ())
+#test((3,) * 2, (3, 3))
+#test(2 * (3,), (3, 3))
+
+--- array-repeat-negative-length ---
+// Error: 2-21 Cannot create array with the length: -5
+#array.repeat(1, -5)