Feature request - A second Random function

[Neon22]

Add a second random function that has its own seed.

The current seed and random function is excellent for the topological changes it allows. But sometimes it would be nice to use a random value to set or add to other aspects and for this to uncoupled from the current rule choice random function.

E.g. { x rand(0,4) } might allow x to be a random value between 0 and 4. This would need its own seed as we would want to control the topology and distance, or color, etc, separately.
The seed would also need to be raised to the UI just like the existing one.

It also means that the current limitation, on having the preprocessor calculate all constants before evaluation, would have to be lifted.
I expect this might slow the generation down but, for me, this is a small price to pay.

[Mikael Hvidtfeldt Christensen]

The program would have to rewritten quite a lot to accommodate this: at the moment all transformation matrices are constructed at parse time - allowing true variables (as the new rand() generator would require) means the internal representation and parsing must be modified to allow for symbolic expressions. This of course would be slower, but also require a lot of changes.

Also, I would like to keep Structure Synth clean - it is not meant to able to express every possible structure, but rather to study the systems imposed by a design grammar. I think this is what makes Structure Synth special (to me) - rather than being just another general purpose programming environment (like Processing), you have to explore and work within the settings of context free design grammar.