Evaluate dice rolling notation strings

Question

Rules

Write a function that accepts string as a parameter, returning evaluated value of expression in dice notation, including addition and multiplication.

To

Answer 1

Ruby, 87 characters, uses eval

Here's my Ruby solution, partially based on the OP's. It's five characters shorter and only uses eval once.

def f s
eval s.gsub(/(\d+)?[dD](\d+)/){n=$1?$1.to_i: 1;n.times{n+=rand $2.to_i};n}
end

A readable version of the code:

def f s
    eval (s.gsub /(\d+)?[dD](\d+)/ do
        n = $1 ? $1.to_i : 1
        n.times { n += rand $2.to_i }
        n
    end)
end