[BEAM-4851] Allow all operators to carry type descriptors of its element

• Type: Sub-task
• Status: Resolved
• Priority: P2
• Resolution: Fixed
• Fix Version/s: Not applicable
• Component/s: dsl-euphoria
• Assignee: Vaclav Plajt
• Reporter: Vaclav Plajt
• Created: 24/Jul/18 06:46
• Updated: 24/Jul/20 20:11
• Resolved: 22/Aug/18 08:16

Description

We need to have an source of `TypeDesctiptor<T>` for each processed element type in order to set/obtain right coder for them. So each operator should be able to tell what is a type of its output, key and value (if applicable).