rpn

System for evaluating Reverse Polish Notation expressions. Logs containing input, timings and results are saved into 'rblog.log' file. Results and timings are printed on stdout.

Usage: go run .\worker.go ruby .\api.rb py .\rpn.py

Make sure to install required dependencies:

1. Go: go get github.com/Scalingo/go-workers
2. Ruby: gem install redis, sinatra, logger, sidekiq
3. Python: pip install requests

Architecture:

1. User interface endpoint (Python):
   • collects input data
   • splits input into a number of RPN expressions
   • requests parsing RPN via REST API
   • gets the results via REST API
   • displays results
2. API (Ruby):
   • defines REST API
   • accepts single RPN expression and triggers worker
   • logs input, results and timings into a file
   • uses Sidekiq for queueing requests
3. Worker (Go):
   • receives RPN expression
   • parses RPN expression and evaluates result
   • saves result in Redis database
   • uses GoWorker + Redis server