movfuscator VS ghc

Everything can be reduced to assignments. https://github.com/xoreaxeaxeax/movfuscator

However, the movfuscator as implemented does still require a sigaction(2) syscall to set up a signal handler, under the justifications that "it is not actually part of the program" and that "if we were in ring 0, we wouldn't need help from the kernel" [0]. However, the latter part seems a little dubious to me: without the help of the kernel running non-MOV instructions, you'd never be able to escape from 16-bit real mode into 32-bit protected mode, since you wouldn't be able to load a valid GDT with the LGDT instruction (as far as I am aware).

[0] https://github.com/xoreaxeaxeax/movfuscator/blob/90a49f31219...

I _think_ the idea is thinking of an "interface" as "something that you use as a way to interact with something from outside an abstraction". I'd summarize their argument as reasoning that if the goal of an abstraction is to avoid having to care about the internal details of something, an interface is a way to expose a subset of ways to interact with it, and the more you expand it, the more it exposes the internals of the thing being abstracted. I don't think they necessarily mean this only in terms of programming, but you could apply this argument to a programming language interface; if you use an interface for interacting with something instead of its direct functionality, each additional method you add to the interface exposes more details of the inner value, which makes it less of an abstraction.

Assuming my interpretation is correct, I'm not sure I totally buy this argument because there doesn't seem to be an obvious way to define the "size" of an interface where it holds true. The naive way to define the size would be number of methods, but I'd argue that methods can vary so much in terms of the amount of cognitive overhead they "expose" to the user that it's not very meaningful. Consider the Movfuscator compiler[0], which compiles code into binaries only using MOV x86 instructions because it happens to be Turing complete; as complex as it might be to learn x86 assembly as a whole and start writing programs directly in it, I'm dubious that trying to do so only with MOV would somehow be easier. Put another way, an x86 instruction set that only contains the MOV instruction is not a "stronger" abstraction than the actual one because it _introduces_ complexity that doesn't exist in the original. Does adding an ADD instruction alongside MOV increase the strength of the abstraction, or weaken it? I don't think there's an answer that we'd immediately all agree on for this sort of thing.

Ultimately, I think trying to measure interfaces through the number of methods they expose is similar to trying to measure code by the number of lines in it; while there are some extreme cases where we'd likely all agree (e.g. for a fizzbuzz implementation, having 10 lines of code is probably better than thousands of lines of code[1]), we can't really come up with a good objective metric because the "target" number is based on the complexity of what you're trying to define, and we don't have a way of quantifying that complexity. I think the ideas here are still super interesting though, not because they have definitive right or wrong answers, but because thinking about stuff like this overall improves one's ability to write good software for usage by other programmers.

[0]: https://github.com/xoreaxeaxeax/movfuscator

The mov instruction in x86-64 is Turing complete. Someone even made a C compiler using only mov.

Are you sure they didn't use the MOVFUSCATOR?

Yep. In fact you can reduce everything to just one simple assembly instruction.

of course it does! what else would you call something like chicken scheme [https://call-cc.org/], ats [https://ats-lang.sourceforge.net/], or ghc [https://www.haskell.org/ghc/]? they are not "scripts", they are full-blown compilers that happen to use C as their compilation target, and then leverage C compilers to generate code for a variety of architecures. it's a very sensible way to do things.

Agree about Haskell... as far as I'm aware there is actually no declarative/easily-readable definition of the Haskell syntax that is also complete, especially when it comes to the indentation rules, and the syntax is basically defined by the very (ironically) imperatively-defined GHC parser[0].

I prefer a syntax like in Pure[1], where the ambiguous, hard to parse indentation-based syntax is replaced by explicit semicolons (Yeah, you can use braces/semicolons in Haskell as well, but most code doesn't).

[0] https://github.com/ghc/ghc/blob/master/compiler/GHC/Parser/L...

[1] https://agraef.github.io/pure-lang/

GHC, the main Haskell compiler

GHCi, version 9.6.3: https://www.haskell.org/ghc/ :? for help Loaded GHCi configuration from /Users/daniel/.ghci ghci> :{ | split :: Float -> [Int] | split value = map(read . (:[])) . show | :} :3:15: error: [GHC-83865] • Couldn't match expected type: [Int] with actual type: a0 -> [b0] • Probable cause: ‘(.)’ is applied to too few arguments In the expression: map (read . (: [])) . show In an equation for ‘split’: split value = map (read . (: [])) . show

GHC is hosted on Gitlab, the Github repo is just a mirror. So money.

https://github.com/ghc/ghc

☁ ~ ghci GHCi, version 9.4.7: https://www.haskell.org/ghc/ :? for help ghci> 6 + 3^2 * 4 42

Depending on who you ask, a programming language can be different things. If you ask the Haskell community, many will tell you that the language is the Haskell specification, and that what currently is being used is not Haskell itself, but an extension of Haskell that is supported by the GHC compiler. Similar to the C language, a programming language would be a specification.

GHCi, version 9.4.2: https://www.haskell.org/ghc/ :? for help Loaded GHCi configuration from ~/.dotfiles/ghc/.ghc/ghci.conf