Evaluate performance of identifier extraction

[physikerwelt]

The length of
https://github.com/TU-Berlin/project-mlp/blob/master/mlp/src/test/java/mlp/text/MathMLUtilsTest.java#L77-77
should be 3, but it's actually 0.
Do I miss something?

[alexeygrigorev]

I don't remember why it's 0, because the assert doesn't quite makes sense for an empty set... anyways the test checks that if the msub expression is too complex, it doesn't produce garbage. And actually if the complex msub wasn't discarded, it appears that the set would contain 1 element.

[alexeygrigorev]

Just to clarify, an identifier is something in <mi>, not inside of <msub> or <msub> - it's done to avoid capturing non-identifiers. E.g. $t_x$ would it this case capture two identifiers t_x and x, while there's just one identifier t_x