My understanding is fourth is still alive and well in the embedded world. A fourth compiler can be written in very few instructions, which is very important when you don't have a lot of memory to work with.
Kinda like BrainF* I see. Turing complete but a readability nightmare. Maybe I should try to write one for FORTH like for BrainF*. Was an interesting exercise especially the loops.
No, the parent is wrong. Maybe on Github Forth interpreters dominate as people's pet projects but there's a good chunk or niche of the embedded industry writing real Forth code every day for new things, not just legacy support. But their code usually isn't on Github. It's a great language for bare metal programming and quite readable, unlike BF which is intentionally unreadable. Forth was designed for low level really (edit: though I remembered there's this if you want an idea of the philosophy http://thinking-forth.sourceforge.net/), I think it's less suitable for higher level general purpose programming just for its untyped nature alone.
You can then look at the definitions for 'WASH' and 'SPIN' and 'RINSE' and so on until you get down to what IO bits you're turning on or reading when and for how long.
I had a friend who was obsessed with Smalltalk in college. He enjoyed showing classmates that you could do things like redefine true and false in the language.
TLDR MRI gets the value of the number directly from value of the C pointer and saves the lookup. It's a 1 in the lowest bit and the integer value in the others. That's why 0.object_id == 1, 1.object_id == 3, etc
Obviously that's implementation dependent but I guess no Ruby implementation is going us to redefine integers if MRI does not.