Controls break when accessing endless range

[izzergh]

When inspecting an endless range (introduced in Ruby 2.6), everything works until typing ( or o. Then the user input is simply written on top of the view.

Steps to recreate:

1. load irb

require 'scryglass'
(1..).scry

3. (optional) confirm scryglass is otherwise working fine - try sending begin or end via c, or returning the object with return, or quitting with q
4. input o or (
5. try doing anything

The workaround if one finds themself in this situation is to background the irb session ctrl+z and kill the process with kill.

Possible solutions

1. Lock the Ruby dependency to < 2.6
2. Check for endless ranges before listing the elements. This can be done by checking begin and end - if either are nil, you have an infinite range on your hands (ruby 2.7 introduces begin-less ranges, iirc). Then simply implement lazy rendering. Or just tell the user "this is infinite! feel free to send methods with c, but you cannot see all elements"