delta-io/delta

[Feature Request][Kernel] Support implicit cast for `DefaultExpressionEvaluator` output.

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#2,047 opened on Sep 12, 2023

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 (3 comments) (0 reactions) (0 assignees)Scala (2,159 forks)batch import
enhancementgood first issuekernelstale

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Description

Feature request

Which Delta project/connector is this regarding?

  • Spark
  • Standalone
  • Flink
  • Kernel
  • Other (fill in here)

Overview

Currently ExpressionHandler.getEvaluator takes an expected output type as argument. The comment here is to handle the implicit cast incase the expression output can be safely cast to the asked output type.

Contributor guide

Research direction
Examine the ExpressionHandler.getEvaluator method and how to safely cast the output of DefaultExpressionEvaluator to the expected output type. Implement implicit casting if safe, following the suggestion in the referenced PR comment.
Tech stack
scala
Domain
backend
Issue type
Feature
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
3
Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.
Half day
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
Active
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
Clear
Prerequisites
ScalaDelta Kernel
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
50