[FLINK-1666] Clean-up Field Expression Code

• Type: Improvement
• Status: Closed
• Priority: Major
• Resolution: Done
• Affects Version/s: 0.9
• Fix Version/s: 1.0.0
• Component/s: API / DataSet
• Assignee: Fabian Hueske
• Reporter: Fabian Hueske
• Created: 09/Mar/15 17:18
• Updated: 26/Jan/16 12:31
• Resolved: 26/Jan/16 12:31

Description

Field expressions are supported at various places in the user facing APIs.
However, not every feature allows exactly the same syntax. Also, code for analyzing field expressions is scattered around several places.

Right now, most of the field expression handling is done in the PojoTypeInfo, CaseClassTypeInfo, and ExpressionKeys classes. Corner cases are inconsistently handled at several other places.

We should clean this up and add one utility class that defines the syntax of field expressions.