Revert ParquetError: PartialEq (#4469)

* Revert ParquetError: PartialEq

* Review feedback

Author: tustvold

parquet/src/errors.rs

@@ -23,6 +23,9 @@ use std::{cell, io, result, str};
 #[cfg(feature = "arrow")]
 use arrow_schema::ArrowError;
 
+/// Parquet error enumeration
+// Note: we don't implement PartialEq as the semantics for the
+// external variant are not well defined (#4469)
 #[derive(Debug)]
 pub enum ParquetError {
     /// General Parquet error.
@@ -44,23 +47,6 @@ pub enum ParquetError {
     External(Box<dyn Error + Send + Sync>),
 }
 
-impl PartialEq for ParquetError {
-    fn eq(&self, other: &Self) -> bool {
-        match (self, other) {
-            (Self::General(l0), Self::General(r0)) => l0 == r0,
-            (Self::NYI(l0), Self::NYI(r0)) => l0 == r0,
-            (Self::EOF(l0), Self::EOF(r0)) => l0 == r0,
-            #[cfg(feature = "arrow")]
-            (Self::ArrowError(l0), Self::ArrowError(r0)) => l0 == r0,
-            (Self::IndexOutOfBound(l0, l1), Self::IndexOutOfBound(r0, r1)) => {
-                l0 == r0 && l1 == r1
-            }
-            (Self::External(l0), Self::External(r0)) => l0.to_string() == r0.to_string(),
-            _ => false,
-        }
-    }
-}
-
 impl std::fmt::Display for ParquetError {
     fn fmt(&self, fmt: &mut std::fmt::Formatter) -> std::fmt::Result {
         match &self {

parquet/src/file/serialized_reader.rs

@@ -810,7 +810,9 @@ mod tests {
         let file_iter = read_from_file.get_row_iter(None).unwrap();
         let cursor_iter = read_from_cursor.get_row_iter(None).unwrap();
 
-        assert!(file_iter.eq(cursor_iter));
+        for (a, b) in file_iter.zip(cursor_iter) {
+            assert_eq!(a.unwrap(), b.unwrap())
+        }
     }
 
     #[test]