Discussion on: Advent of Ruby 3.0 - Day 01 - Report Repair

[Josh Cheek]

File.readlines(ARGV[0]).then { puts product_duals(_1) }

For this one, I've started using ARGF, which allows it to receive the argument on stdin or as a filename. So this works the same and is a bit more flexible: ARGF.then { puts product_duals(_1) }. At this point, I suppose, it's a bit difficult to justify the then, but there's 25 of these things, I'm sure the will be plenty of opportunities 😜

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Also, thanks for talking about then, and implicit arg references. I had heard about both but not played with them enough to internalize them. I've been doing tap + break, and explicit arguments 😐

2.tap { |v| break v + 3 }  # => 5
2.then { _1 + 3 }          # => 5

[Brandon Weaver]

Y'know I always forget about ARGF because of how rarely I write CLI type scripts. Admittedly I put then in there just to demonstrate that it works.

[Peter Cooper]

You can even go a step further with $<.read or $<.readlines - I've been doing this in my "golfed" solutions.