Show truncation indicator when display values exceed limit

Signed-off-by: Dimitar Dimitrov <dimitar@spiraldb.com>

Author: dimitarvdimitrov

vortex-array/src/display/mod.rs

@@ -29,7 +29,7 @@ pub enum DisplayOptions {
     /// );
     /// ```
     MetadataOnly,
-    /// Only the logical values of the array: `[0i16, 1i16, 2i16, 3i16, 4i16]`.
+    /// Only the first 16 logical values of the array: `[0i16, 1i16, 2i16, 3i16, 4i16]`.
     ///
     /// ```
     /// # use vortex_array::display::DisplayOptions;
@@ -332,7 +332,7 @@ impl Display for dyn DynArray + '_ {
 
 const DISPLAY_LIMIT: usize = 16;
 impl dyn DynArray + '_ {
-    /// Display logical values of the array
+    /// Display the first 16 logical values of the array
     ///
     /// For example, an `i16` typed array containing the first five non-negative integers is displayed
     /// as: `[0i16, 1i16, 2i16, 3i16, 4i16]`.
@@ -490,7 +490,8 @@ impl dyn DynArray + '_ {
                             .map_or_else(|e| format!("<error: {e}>"), |s| s.to_string()))
                         .format(sep)
                 )?;
-                write!(f, "{}", if f.alternate() { "\n]" } else { "]" })
+                let end = if self.len() > limit { ", ...]" } else { "]" };
+                write!(f, "{}{end}", if f.alternate() { "\n" } else { "" })
             }
             DisplayOptions::TreeDisplay {
                 buffers,
@@ -583,6 +584,7 @@ mod test {
     use crate::arrays::BoolArray;
     use crate::arrays::ListArray;
     use crate::arrays::StructArray;
+    use crate::display::DISPLAY_LIMIT;
     use crate::dtype::FieldNames;
     use crate::validity::Validity;
 
@@ -596,6 +598,15 @@ mod test {
 
         let x = buffer![1, 2, 3, 4].into_array();
         assert_eq!(x.display_values().to_string(), "[1i32, 2i32, 3i32, 4i32]");
+
+        let x = crate::arrays::PrimitiveArray::from_iter(
+            0i32..i32::try_from(DISPLAY_LIMIT).unwrap() + 1,
+        )
+        .into_array();
+        assert_eq!(
+            x.display_values().to_string(),
+            "[0i32, 1i32, 2i32, 3i32, 4i32, 5i32, 6i32, 7i32, 8i32, 9i32, 10i32, 11i32, 12i32, 13i32, 14i32, 15i32, ...]"
+        );
     }
 
     #[test]