[GitHub] [arrow] lidavidm commented on a change in pull request #12000: ARROW-14705: [C++][Python] Handle more types in UnifySchemas

[GitBox <gi...@apache.org>]

lidavidm commented on a change in pull request #12000:
URL: https://github.com/apache/arrow/pull/12000#discussion_r774613715



##########
File path: cpp/src/arrow/type.h
##########
@@ -303,14 +303,73 @@ class ARROW_EXPORT Field : public detail::Fingerprintable {
   /// \brief Options that control the behavior of `MergeWith`.
   /// Options are to be added to allow type conversions, including integer
   /// widening, promotion from integer to float, or conversion to or from boolean.
-  struct MergeOptions {
+  struct ARROW_EXPORT MergeOptions : public util::ToStringOstreamable<MergeOptions> {
     /// If true, a Field of NullType can be unified with a Field of another type.
     /// The unified field will be of the other type and become nullable.
     /// Nullability will be promoted to the looser option (nullable if one is not
     /// nullable).
     bool promote_nullability = true;
 
+    /// Allow a decimal to be unified with another decimal of the same
+    /// width, adjusting scale and precision as appropriate. May fail
+    /// if the adjustment is not possible.
+    bool promote_decimal = false;
+
+    /// Allow a decimal to be promoted to a float. The float type will
+    /// not itself be promoted (e.g. Decimal128 + Float32 = Float32).
+    bool promote_decimal_float = false;
+
+    /// Allow an integer of a given bit width to be promoted to a
+    /// float of an equal or greater bit width.

Review comment:
       As implemented, you need also `promote_numeric_width` to unify int64 and float32 (to float64).




-- 
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.

To unsubscribe, e-mail: github-unsubscribe@arrow.apache.org

For queries about this service, please contact Infrastructure at:
users@infra.apache.org