Calculation Reverse Polish Notation with Ruby

reverse_polish_notation.rb

#jurias from codewars
def calc(expr)
  expr
    .split(' ')
    .reduce([0]) { |s, i| s << (i =~ /[0-9.]/ ? i.to_f : s.pop(2).reduce(i.to_sym)) }
    .pop
end

#my code -_-
def calc1(expression) 
  values = expression.split(" ")
  return 0 if expression.empty?
  math_operator = /[\+\-\*\/]/.match(expression).to_s
  numbers = []
  check_value = ->(val){/(\d+[.]\d+)/.match(val) ? val.to_f : val.to_i}
  
  if math_operator && !math_operator.empty?
    values.each{ |i|
        if i.to_i > 0 
          numbers << i.to_i
        else
          last = numbers.pop
          first = numbers.pop
          numbers << first.send(i, last)
        end
    }
    numbers.last
  else
    value = expression.split(' ').last
    check_value.call(value)
  end  
end

reverse_polish_notation_spec.rb

RSpec.describe "Challenge" do
  it "should work for an empty string" do
    expect(calculate("")).to eq(0)
  end
  it "should parse numbers" do
    expect(calculate("1 2 3")).to eq(3)
  end
  it "should parse floats" do
    expect(calculate("1 2 3.5")).to eq(3.5)
  end
  it "should support addition" do
    expect(calculate("1 3 +")).to eq(4)
  end
  it "should support multiplication" do
    expect(calculate("1 3 *")).to eq(3)
  end
  it "should support subtraction" do
    expect(calculate("1 3 -")).to eq(-2)
  end
  it "should support division" do
    expect(calculate("4 2 /")).to eq(2)
  end
  it "should support complexity expression" do
    expect(calculate("1 2 3 * +").to eq(7))
  end
end