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POJava formula evaluation library with out-of-order variables feature
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  1. POJava formula evaluation library with out-of-order variables feature
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    copied!<p>I'm currently looking for a java library (or native library with a java API) for formula parsing and evaluation.</p> <p>Using recommandations from here, I took a look on many libraries :</p> <ul> <li>JFormula</li> <li>JEval</li> <li>Symja</li> <li>JEP</li> </ul> <p>But none of them fulfil my needs, that are :</p> <ul> <li>Multiple formula evaluation with dependency between them (a formula is always an affectation to a variable using other variables or numerical values)</li> <li>Possibility to change only one formula out of maybe 50, with good performances if only one formule changes</li> <li>no need to handle by hand variables dependancies</li> <li>Automatically update other dependant variables if a formula changes</li> <li>Possibility to listen which variable changed</li> <li>no need to have a specific format for the variables (the user will directly enter a name and doesn't want to have a complexe notation)</li> </ul> <p>Maybe an exemple will be better. Let's say we have, entered in the system in this order :</p> <ul> <li>a = b + c</li> <li>c = 2 * d</li> <li>b = 3</li> <li>d = 2</li> </ul> <p>I would like to be able to enter those 4 lines in this order, and ask for the result of "a" (or "b", whatever). Then if in the user interface (basically a table variable &lt;> formula) "b" is changed to "2 * d", the library will automatically change the value of "b" and "a", and return me (or lunch an event, or call a function) a list of changes </p> <p>The best library would be one just like JEP, but with the out-of-order variables capability and the possibility to auto-evaluate dependant variables</p> <p>I know that compilers and spreadsheet softwares uses such mechanisms, but I didn't found any java or java compatible libraries directly usable</p> <p>Does someone know one?</p> <p>EDIT : Precision : the question is really about a library, or eventually a set of libraries to link together. The question is for a project in a company and the idea is to spend the minimum amount of time. The "do it yourself" solution has already been estimated and is not in the scope of the question</p>
 

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