When adjacent lines are executed the same # of times, align the output values

[JoshCheek]

Eg, consider this program

node3 = ['c']
node2 = ['b', node3]
node1 = ['a', node2]

node = node1
while node
  node[0] # => "a", "b", "c"
  node[1] # => ["b", ["c"]], ["c"], nil
  node = node[1]
end

It would be nice for the outputs to line up, like so:

node = node1
while node
  node[0] # => "a",          "b",   "c"
  node[1] # => ["b", ["c"]], ["c"], nil
  node = node[1]
end

[JoshCheek]

+1

[JoshCheek]

I've added this as a feature and turned it on by default (I try to make the defaults what I think most people would want it to do rather than avoiding change -- if avoidance of change is desired, there are flags to explicitly set a default).

It works on both normal SiB and xmpfilter style. @avdi and @jcinnamond if you wouldn't mind installing it locally and letting me know if it's better or worse / if there are changes I should make, I'd appreciate it (clone, gem build seeing_is_believing.gemspec, gem install seeing_is_believing-3.0.1.gem).

I just kept winding up wanting to show how results on one line matched up with results on the next, but their inspected value didn't line up, so I wound up editing the comments by hand on many occasions.

If it annoys you, you can turn it off with the --no-interline-align option.

The feature is here for SiB style and here for xmpfilter style.

---

Other recent changes:

• I also just fixed xmpfilter "next-line" style to record the previous expression (issue). So, eg, you can place it after a heredoc.
• It also records inside of class namespaces (issue)

• You can generally fuck with the environment without SiB breaking (there were a few I couldn't get), the most common example was when I was trying to show people that they could make their own Class.new, it used to break SiB (SiB instantiated classes, which would get recorded, which would instantiate classes, which would... eventually this would overflow the stack)

  class Class
  def new(*args, &block)
    instance = allocate                            # => #<A:0x007f883386ec88>
    instance.__send__(:initialize, *args, &block)  # => 123
    instance                                       # => #<A:0x007f883386ec88 @arg=123>
  end                                              # => :new
  end                                                # => :new
  
  class A
  attr_reader :arg     # => nil
  def initialize(arg)
    @arg = arg         # => 123
  end                  # => :initialize
  end                    # => :initialize
  
  A.new(123).arg  # => 123

[JoshCheek]

I haven't released it yet, so there is time to change defaults.