Possible to extract variables from Expression?

[herrytco]

For my project, I need to parse expressions and get a list of used symbols in that expression. This would look something like this:

String input = "x+y*z+3";
Expression e = Parser().parse(input);

List<String> symbols = e.symbols; // ["x", "y", "z"]

Is that possible with the current state? I couldn't find the function on my own.

[fkleon]

Hi @herrytco thanks for creating this issue. It's currently not possible to get a list of symbols/variables directly from the expression tree.

[herrytco]

Thank you for the answer. Than I fall back to my current strategy to do the following:

1. try to evaluate the expression
2. catch all errors related to unbound variables
3. set the variable to a random value
4. repeat 2-3 until the expression is evaluated
5. return the list of symbols found
6. profit

[VittorioParagallo]

any plan to implement this feature?

[fkleon]

any plan to implement this feature?

No, but feel free to open a PR if you're wanting to contribute this.