Ruby evaluate without eval?

Question

How could I evaluate at mathematical string without using eval?

Example:

mathstring = \"3+3\"

Anyway that can be evaluated without

Answer 1

Dentaku seems (I haven't used it yet) like a good solution - it lets you check your (mathematical and logical) expressions, and to evaluate them.

calculator = Dentaku::Calculator.new
calculator.evaluate('kiwi + 5', kiwi: 2)