Draft: Add sequence generators

Add the first draft of the new sequence generator. Includes the new Sequence class which can be updated via a visitor pattern. Additionally, adds the first visitor. Change pom.xml to include the minimal Expression Parser Exp4j, which allows to parse Strings into mathematical functions.

Closes #160

added componentgenerator issue-typefeature-request workflowdiscussion labels

assigned to @berber

We have our own expression language within EvoAl (it is part of the base language) and there is already an interpreter: de.evoal.languages.model.interpreter.ConstantExpressionEvaluator. We have to adapt it slightly so it meets your requirements (a non-caching variant with a custom symbol table) but that should be easy. Perhaps, in the first step, you implement a +1 in the code and if that is working, we can replace it with an interpreter.

Neat, then I would focus on creating the +1 series hard coded for now and then move forward to the parser.

I leave this open for now as we will look into this if the easy stuff works

added 4 commits

• 7f08b19c - Change to the easiest sequence n+1. Sadly only hard coded.
• f6eea302 - Remove unused code
• 1220ffe4 - Add the first iteration of the new sequence type
• c0d42842 - Rename the sequence.dl to timeseries.dl

Compare with previous version

I made some small changes and hopefully everything works now as intended. At least the pipeline is running smoothly.

Is there a proper way to test this new functionality or is it enough to write an example for it?

I have looked around a bit more and found the AbstractGeneratorFunction Interface. Why are we not using this one?

PS: Regarding AbstractGeneratorFunction: It is a good idea to use this as a base implementation. I forgot that the class exists.

Okay, then I will look into it and change the implementation.

added 15 commits

• c0d42842...6c57172d - 3 commits from branch develop
• 6c57172d...8e3b7790 - 2 earlier commits
• 7d37a31e - Switch from the generator version to the pipeline world. Change inheritance...
• ce2413f7 - Move the Sequence to the proper location
• d9bb110c - Implement the Sequence interface and get rid of the unneccesarry inheritance...
• d30a6509 - Add the most basic implementation of a sequence
• d57557e9 - Change imports after switch to the pipeline workflow
• 96be698e - Make sequence implentation available
• 18c67b86 - Refines sequence implementation
• 7a72d723 - Add example for sequence generation
• ea720255 - Delete old ddl
• d0560b25 - Add the Base sequence class

Compare with previous version

I have merged the most recent dev branch and finished implementing the sequence generator. As far as I can see everything seems to be working as intended:

• I am able to create a small timeseries (n+1) starting from 0
• For testing purposes I added a small generate-timeseries example

Hopefully everything is at the right place and works proper.