Can one calculate X = 10 * Y + X in a single step (i.e., as a single expression), in a Flow service?
– It is crazy to have a separate MAP for each elementary math operation!

Writing a java service would be even more insane for this purpose than invoking multiple simple operations. I agree that the situation is absolutely horrible for anyone coming from other programming languages.

One could create a java service that would calculate any math expression – e.g. using JavaScript in the implementation. I’m not sure about the performance, but if it doesn’t matter then math calculations would be much more elegant. E.g. create a service having 5 parameters: x, y, z, t and expr. Expr is a string that specifies the expression to calculate. In the expression, you can use x, y, z and t. This would be a universal calculator for expressions having no more than four variables.

But the truth is that (at least according to my experience) complex math calculations are a rare thing in wM code. wM is used for integration where calculations usually do not happen often.