fcl VS eo

I implemented by own Forth dialect and made it open source. The calculator is programmable, so you can write new words/operators, assign them to buttons or evaluate code snippets.

Forth calculator is a programmable calculator app for Android that uses a Forth dialect what I made solely for the App. The language is fully open sourced. I don't think there is anything ground breaking in it, and it is certainly not super performant, but I like how the optional local variable support turned out.

Looking at the commit history of eo, I'm not certain that PR size, or testing methodology for that matter, should be the #1 concern of Yegor's team.

They do have a paper in the repo: https://github.com/cqfn/eo/tree/master/paper

According to it, "𝜑-calculus" is something they made up for the eolang and not a standard term.

Here is my take on that calculus based on reading through section 3 in the paper. Note the paper is pretty weird and likes to make its own notation, so it is possible I got some things wrong:

It is starts with a pretty standard immutable language: "object" is a set of (name, value) pairs; "value" is either object or "data" (like a string, bool etc...); everything is immutable but you can make a copy an object with some attributes changed. There are no concept of "types" -- instead, you define objects with some fields set to NULL (spelled ∅ in the paper). There are also a bunch of term defined, like "abstraction", "application", etc.. -- but they all mean "make a copy of an object with some fields changed".

The "twist" is that the language has no functions per se, instead it defines AST-like structure: there is a syntactic sugar that handles things that look like function applications. So when you see:

     stdout "Hello world"