Remove redundant implementation of StringArrayType

Signed-off-by: Tai Le Manh <[email protected]>

arrow-string/src/like.rs

@@ -18,11 +18,12 @@
 //! Provide SQL's LIKE operators for Arrow's string arrays
 
 use crate::predicate::Predicate;
+
 use arrow_array::cast::AsArray;
 use arrow_array::*;
 use arrow_schema::*;
 use arrow_select::take::take;
-use iterator::ArrayIter;
+
 use std::sync::Arc;
 
 #[derive(Debug)]
@@ -150,39 +151,6 @@ fn like_op(op: Op, lhs: &dyn Datum, rhs: &dyn Datum) -> Result<BooleanArray, Arr
     }
 }
 
-/// A trait for Arrow String Arrays, currently three types are supported:
-/// - `StringArray`
-/// - `LargeStringArray`
-/// - `StringViewArray`
-///
-/// This trait helps to abstract over the different types of string arrays
-/// so that we don't need to duplicate the implementation for each type.
-pub trait StringArrayType<'a>: ArrayAccessor<Item = &'a str> + Sized {
-    /// Returns true if all data within this string array is ASCII
-    fn is_ascii(&self) -> bool;
-    /// Constructs a new iterator
-    fn iter(&self) -> ArrayIter<Self>;
-}
-
-impl<'a, O: OffsetSizeTrait> StringArrayType<'a> for &'a GenericStringArray<O> {
-    fn is_ascii(&self) -> bool {
-        GenericStringArray::<O>::is_ascii(self)
-    }
-
-    fn iter(&self) -> ArrayIter<Self> {
-        GenericStringArray::<O>::iter(self)
-    }
-}
-impl<'a> StringArrayType<'a> for &'a StringViewArray {
-    fn is_ascii(&self) -> bool {
-        StringViewArray::is_ascii(self)
-    }
-
-    fn iter(&self) -> ArrayIter<Self> {
-        StringViewArray::iter(self)
-    }
-}
-
 fn apply<'a, T: StringArrayType<'a> + 'a>(
     op: Op,
     l: T,

arrow-string/src/regexp.rs

@@ -18,8 +18,6 @@
 //! Defines kernel to extract substrings based on a regular
 //! expression of a \[Large\]StringArray
 
-use crate::like::StringArrayType;
-
 use arrow_array::builder::{BooleanBufferBuilder, GenericStringBuilder, ListBuilder};
 use arrow_array::cast::AsArray;
 use arrow_array::*;