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Visualize Ruby .each loops!
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Hi! Welcome! This is Looper, a Ruby loop animator. It's meant to take in a small snippet of ruby .each code and display the values of all variables through various stages. Great for beginners learning to code. Feel free to clone it, fork it, give it a loop, and let me know how it went!

WARNING: Do not host Looper on a public server. It is insecure AF! Looper uses Ruby's .eval(string), which gives tremendous power to the string it evaluates.

built with
  • Ruby on Rails in the backend, looperBack
  • React, Redux, MaterialUI in the frontend, looperFront
future plans

I intend to continue working on Looper so that by the end of 2019:

  • it'll be easier on the eye to follow (colors!)
  • add a kind of setTimeout so the animation can run itself
  • totally revamp the backend to accomodate more than 1 line in the block (maybe)
  • support other Ruby loops: .collect, .select, etc
  • it'll be secure enough to host (fingers crossed)
  • if it's still not secure enough, I'll look into some kind of sandboxing method.

story behind Looper

When I first learning to code, I found it very difficult to keep track of the iterative pattern and all the syntax to set it up. I also didn't know binding.pry existed, so I stuck puts everywhere. It was very tedious and I always wished there was some kind of tool that would show me what each variable's value was at the end of every line. So I made Looper. I hope it can help others learn to code because coding can be so fun.

three ways to "parse"

Right now, Looper looks and works kind of like how I initially dreamed it would. While making Looper, I came up with at least 3 ways I could make this happen:

  1. make a parser and lexer
  • Why I Didn't: I felt pressed for time and was not confident I'd learn all the tools to make it work in time. (Looper started as a graduation project)
    • I looked at some videos for making parsers and lexers, as well as slides from Universities CS courses, and it looked like I would need at least a couple weeks to understand how it all worked, and another couple weeks to make my own for the Ruby language.
    • I'd be reimplementing the Ruby interpreter? I should probably look up how the Ruby interpreter does it first.
  1. take in a string of code, and stick puts in between every line. Use I/O File class to run it as another file, such that it puts to the command line, and then return the command line outputs.
  • Why I Didn't: See above, but not as extreme.
  1. take in a string of code, collect all variable values in an array, and then make an array of those variable_values array.
  • Why I Did: I didn't need to deal with the I/O File class :D (yes, I was a bit lazy here)

... TBD!

Last Updated: Jan 08, 2018

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