EvalEx now used in TSTool software for time series workflow automation

[smalers]

I am the main developer of the TSTool software, which is an open source Java application to process time series and other data. It has been developed for natural resources data such as climate and hydrology time series and associated data sources, and is used by various entities involved with water resources. See: https://opencdss.state.co.us/tstool/.

I was not able to use the latest EvalEx until recently when I updated TSTool to Java 11. And, ChatGPT was help in finding EvalEx in the first place. I looked at other alternatives but decided to give EvalEx a try because of its features, small size, and no dependencies. Here is the TSTool command that uses EvalEx:

EvaluateExpression

The point I will make here is that I am interested in whether any readers are looking for a solution like TSTool and whether further EvalEx integration that I do would meet additional needs. Now that I have taken a first cut at integrating, I will be using EvalEx in other TSTool commands and mapping things appropriately because TSTool works with the same types of objects, but has different classes (DateTime, etc.). One thing that seems to be missing is a POW() function. TSTool has built-in features for automated testing (compare files, time series, tables, etc.) that are useful when testing at a higher level in a production environment.

Perhaps it makes sense to have a list of applications that use EvalEx so that users can look at implementations in source code and possibly also use those applications? Sorry if that exists and I missed. I know it can be a pain to keep such lists up to date so maybe keep it simple and short?

I have not used GitHub discussions before but am hoping for a useful discussion. Thanks.

[uklimaschewski]

Thank you for starting this discussion.

I agree that it would eb hard to maintain such a list, because the information have to be provided by the developers of those applications.
If the applications/tools that use EvalEx are also on Maven Central, then you could search for the dependencies, e.g. here.

The POW function is missing, because EvalEx has a power-of operator.

There is also good support for date/time values and converting from/to various formats and types.
See Working with Date-Times and Duration.
Also of interest: Evaluation Value Converter

Data types in EvalEx are quite flexible, you may use structures for your own custom data types. We also have added the binary data type now, allowing you to pass any Java object as a variable value.
Of course, if you want to use operators or functions on a new object type, the operators and functions have to be extended or newly implemented. The configurable operator and function dictionary can help you with that kind of customization.

[smalers]

Maybe developers can use AI-driven search engines could be used to ask "What software uses the Java EvalEx library?" rather than maintaining a list. I tried in Google and it did not have a useful answer. ChatGPT mentioned JasperReports and Jenkins. It could be that software developers need to do a better job of making the dependency obvious to search engines. The main point I was trying to make is that sometimes it is useful to see how someone has implemented a library in a common application.

Maybe still add a pow() function and you could just document that it is equivalent to the power-of operator? That would make it easier to correlate with Java Math.pow(). And, the syntax of an expression may be easier to understand and troubleshoot with a function. It is not a huge deal to me.

I'll leave this discussion open for a bit to see if anyone needs a tool like I mentioned but will then close it if no comments are added.