[CALCITE-5706] Add class PairList

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 1.35.0
• Labels: pull-request-available
• Assignee: Julian Hyde
• Reporter: Julian Hyde
• Created: 17/May/23 00:38
• Updated: 27/Jul/23 10:22
• Resolved: 28/Jun/23 19:15

Description

Add a class PairList which is an implementation of List<Map.Entry<K, V> backed by a single list. Each entry to the PairList corresponds to two entries in the backing list, but we save ourselves the effort of creating Map.Entry wrappers.

A PairList can be used to build two lists in parallel (e.g. a list of field types and field names that will be converted to a struct type); it can also be used to build maps.

It has a forEach(BiConsumer<K, V>) method to allow the list to be deconstructed without creating intermediate entries.

Potentially also toImmutableMap and toHashMap methods.

Issue Links

• links to: Dev branch
• links to: GitHub Pull Request #3250