Add ability to clear variables in expression

[amila]

Hi,

I just wanted to contribute a very simple change. I wanted to provide the client side to be able to clear the variables set or if a map is passed in to clear the old state.

I have a process that cycles through a series of expressions against different maps with different variables and values.
eg:
expressions = {
expression 1: a + b
expression 2: x - y
}

I have a list of maps with different values:
maps = {
map1: a->1, b->2,
map2: x>5, y->2
}
expression1.setVariables(map1);
expression1.validate(true); will return a true, which is correct!
If immediately after I do expession1.setVariables(map2) this will also return a true, which is incorrect as map2 has variables x and y and not a and b. It returns true because the expression has state with regards to the variables.

For the reason I mentioned above I suggest a clearing of the data. I hope you find this contribution of some benefit to you.

Thanks,
Sajith

[fasseg]

Hey Sajith,

Adding a method to clear the variables is possible and makes sense, but clearing the variables in the setVariables(Map) call is not possible. This is an API Change and will break existing software using exp4j.