Parses a mathematical expression from infix notation into reverse polish notation and produces a result.
Add this line to your application's Gemfile:
gem 'math_expr'And then execute:
$ bundle install
Or install it yourself as:
$ gem install math_expr
require 'math_expression/parser'
parser = MathExpression::Parser.new('4 + 5')
parser.to_tokens # => [{:type=>:number, :value=>4}, {:type=>:operator, :value=>"+"}, {:type=>:number, :value=>5}]
parser.to_postfix # => [4, 5, "+"]
parser.evaluate # => 9After checking out the repo, run bin/setup to install dependencies. Then, run rake respec to run the tests. You can also run bin/console for an interactive prompt that will allow you to experiment.
To install this gem onto your local machine, run bundle exec rake install. To release a new version, update the version number in version.rb, and then run bundle exec rake release, which will create a git tag for the version, push git commits and tags, and push the .gem file to rubygems.org.
Bug reports and pull requests are welcome on GitHub at https://github.com/inclooder/math_expression.
The gem is available as open source under the terms of the MIT License.