fix: Dict LikeFn length mismatch (#2043)

before this PR, LikeFn takes a `pattern: &ArrayData` argument, but for
the DictArray implementation, it would only (accidentally) return a
correct result if `pattern` was a `ConstantArray`

encodings/dict/src/compute/like.rs

@@ -1,3 +1,4 @@
+use vortex_array::array::ConstantArray;
 use vortex_array::compute::{like, LikeFn, LikeOptions};
 use vortex_array::{ArrayData, IntoArrayData};
 use vortex_error::VortexResult;
@@ -10,8 +11,15 @@ impl LikeFn<DictArray> for DictEncoding {
         array: DictArray,
         pattern: &ArrayData,
         options: LikeOptions,
-    ) -> VortexResult<ArrayData> {
-        let values = like(array.values(), pattern, options)?;
-        Ok(DictArray::try_new(array.codes(), values)?.into_array())
+    ) -> VortexResult<Option<ArrayData>> {
+        if let Some(pattern) = pattern.as_constant() {
+            let pattern = ConstantArray::new(pattern, array.values().len()).into_array();
+            let values = like(array.values(), &pattern, options)?;
+            Ok(Some(
+                DictArray::try_new(array.codes(), values)?.into_array(),
+            ))
+        } else {
+            Ok(None)
+        }
     }
 }

vortex-array/src/compute/like.rs

@@ -11,7 +11,7 @@ pub trait LikeFn<Array> {
         array: Array,
         pattern: &ArrayData,
         options: LikeOptions,
-    ) -> VortexResult<ArrayData>;
+    ) -> VortexResult<Option<ArrayData>>;
 }
 
 impl<E: Encoding> LikeFn<ArrayData> for E
@@ -24,7 +24,7 @@ where
         array: ArrayData,
         pattern: &ArrayData,
         options: LikeOptions,
-    ) -> VortexResult<ArrayData> {
+    ) -> VortexResult<Option<ArrayData>> {
         let encoding = array
             .encoding()
             .as_any()
@@ -58,20 +58,32 @@ pub fn like(
     if !matches!(pattern.dtype(), DType::Utf8(..)) {
         vortex_bail!("Expected utf8 pattern, got {}", array.dtype());
     }
+    if array.len() != pattern.len() {
+        vortex_bail!(
+            "Length mismatch lhs len {} ({}) != rhs len {} ({})",
+            array.len(),
+            array.encoding().id(),
+            pattern.len(),
+            pattern.encoding().id()
+        );
+    }
+
     let expected_dtype =
         DType::Bool((array.dtype().is_nullable() || pattern.dtype().is_nullable()).into());
     let array_encoding = array.encoding().id();
 
-    let result = if let Some(f) = array.encoding().like_fn() {
-        f.like(array, pattern, options)
-    } else {
-        // Otherwise, we canonicalize into a UTF8 array.
-        log::debug!(
-            "No like implementation found for encoding {}",
-            array.encoding().id(),
-        );
-        arrow_like(array, pattern, options)
-    }?;
+    let result = array
+        .encoding()
+        .like_fn()
+        .and_then(|f| f.like(array.clone(), pattern, options).transpose())
+        .unwrap_or_else(|| {
+            // Otherwise, we canonicalize into a UTF8 array.
+            log::debug!(
+                "No like implementation found for encoding {}",
+                array.encoding().id(),
+            );
+            arrow_like(array, pattern, options)
+        })?;
 
     debug_assert_eq!(
         result.len(),
@@ -97,6 +109,12 @@ pub(crate) fn arrow_like(
 ) -> VortexResult<ArrayData> {
     let nullable = array.dtype().is_nullable();
     let len = array.len();
+    debug_assert_eq!(
+        array.len(),
+        pattern.len(),
+        "Arrow Like: length mismatch for {}",
+        array.encoding().id()
+    );
     let lhs = unsafe { Datum::try_new(array)? };
     let rhs = unsafe { Datum::try_new(pattern.clone())? };