It mapped from Ruby to C# really well. The only concept I had to add was a `BoardCell` base type for the `Mine` and `Empty` types so we could return either `Mine` or `Empty` in a typesafe way. Everything else matched conceptually 1-1.
It's 118 lines total, with 18 lines of whitespace, so 100 lines exactly. I figure the original Ruby code was also not counting whitespace so it's a fair comparison. I tried to not use any "code golf tricks" that would minimize line count. It's a full program; it could be copy/pasted into a modern .NET 8 project and run without any additional setup.
Note, I posted this same comment on the original blog post, but I've posted it here too as it might be interesting for HN folks.