[ARROW-18328] [C++] Remove legacy scanner code where possible

• Type: Improvement
• Status: Open
• Priority: Major
• Resolution: Unresolved
• Component/s: C++
• External issue URL: https://github.com/apache/arrow/issues/33498
• Assignee: Weston Pace
• Reporter: Weston Pace
• Created: 15/Nov/22 01:20
• Updated: 11/Jan/23 11:59

Description

Once everything has converted over to the non-async-generators scanner then there should be a fair amount of legacy code that can be safely removed (this is internal code so no need to worry about deprecation cycles). This JIRA mainly exists as a placeholder to mark in comments places that should be cleaned up.