4 ms·

The Kernel Programming Language

74 points by adgasf 8y ago

orthoxerox 8y ago
I wonder if it's possible to infer the types of a Kernel program.
- sparkie 8y ago
  Certainly not with our existing type systems. It might be possible if somebody could come up with a new system with the vau calculus at its core rather than lambda calculus (as Hindley-Milner etc. are). I think it would be a dead-end with kernel-standard though. The presence of mutability and cyclic data structures seems like the problem would be as unsolvable as the halting problem. For any serious investigation of type inference, you would probably need to stick to an immutable Kernel subset. The Kernel Report does make mutability optional.
  - CuriousSkeptic 8y ago
    Hmm, I don’t see why vau-calculus should change things. Fexpr are more or less like expression trees in C# no? (Which are statically typed, at least where they compose with the rest of the program). Granted, dynamic languages in general can be a challenge, but TypeScript is a good argument for it being feasible at least.
fake-name 8y ago
> The Kernel Programming Language Because no one uses `kernel` for anything already. I mean, holy fucking hell, if you're creating a programming language, choose a name that you can fucking search for.
- giancarlostoro 8y ago
  I vote they choose Colonel instead if they do any sort of rename.
- ummonk 8y ago
  I think the next programming language I write will be named the Software Programming Language.
  - Midnightas 8y ago
    Mine will be called simply Programming Language.
    - keithalewis 8y ago
      How about A Programming Language https://en.wikipedia.org/wiki/APL_(programming_language) https://en.wikipedia.org/wiki/APL_(programming_language)? Yeah, that's the ticket.
      - adharmad 8y ago
        And a recursive acronym to boot!
      - pgeorgi 8y ago
        Or Programming Language One (https://en.wikipedia.org/wiki/PL/I https://en.wikipedia.org/wiki/PL/I)
    - klyrs 8y ago
      Mine will be a scripting language called Compiler
      - 9dev 8y ago
        Mine will be called lang. The docs can be found on the official website, langlang.org of course.
- coldtea 8y ago
  >Because no one uses `kernel` for anything already. Because people will seriously be perplexed between an esoteric experimental programming language and operating system kernels, right? Like that huge fiasco in the early 50s, when people confused OS kernels with corn...
  - justaaron 8y ago
    no, it's called a "search result"
    - coldtea 8y ago
      We have C, a language named after a letter, and Go, a language named after a verb, and your issue is with "Kernel"? Just fucking add fucking "programming language" as the suffix to your fucking query about Kernel the PL, to mimic the tone of the original comment.
      - fake-name 8y ago
        C, which was named before search engines were a thing, and Go, which is also a terrible name, but google is big enough they can make it work. Also, it's not like things like the linux kernel have a specific enough dialect of C it could be considered a programming dialect/language itself, so there are multiple layers of poor naming here. The point is if you want people to use your esoteric programming language, you want to minimize any blatantly obvious pain points. Choosing a decent name is a very easy pain point to avoid.
      - seandougall 8y ago
        Searching for “kernel programming language” mostly turns up a bunch of results about what programming languages are good for kernel programming. Adding words doesn’t always disambiguate. I mean, it doesn’t turn up any results about corn, so I guess that’s something, but beyond that it doesn’t seem terribly helpful.
  - fake-name 8y ago
    People, no. Pretty much every search engine ever? Ohhhhh yeeeaaahhh. Besides, the Linux kernel has a specific-enough dialect of C that I assumed this was about linux kernel programming based on the title.
deleted 8y ago
[deleted]
klibertp 8y ago
The same idea - allowing a procedure to get either a reference to a value or syntactic description of the value coupled with the dynamic environment from the procedure call-site - is implemented in Io language. Io is a purely OO language influenced by Smalltalk and Self the most; it has only objects and no classes, objects have named slots which reference other objects (some of which are "activatable" - callable, IOW - and they're then called methods) and all computation happens by sending messages between objects. If a message name corresponds to the slot name which holds a method, that message send (by default) results in the method being called. Messages are just objects, which carry both dynamic environments from the place they were sent and the arguments, which are passed as message objects themselves. The method may then choose to evaluate some of the messages passed as arguments or not; but it can also change the messages before evaluating them, as the Message objects are mutable and respond to many of the same messages that Lists respond to, including `setAt(idx, val)` for example. (One tricky part of all of this is getting the relation between Message objects and message-sends in Io. In short, Messages are objects which have target, name, and a list of arguments. These objects can be both serialized into, and read from a string, in which case they look like this: target msgName(arg1, arg2, ...) The place in program text and the lexical environment at that point is a message-send, while Message is a runtime representation of that message-send and it references dynamic environment at the point of call. And BTW, in the syntax of message-send above, both `target` and `(arg1, ...)` are optional. In Io, code like this: 1 is, in fact, a message send with `name` set to `"1"`; it's first sent to the current `this` object, and then bubbles up the inheritance chain to `Object`, which handles the message by returning a Number object with value of `1`.) The effect is really interesting: the language is incredibly expressive, with metaprogramming support rivaling Lisp (Io is also homoiconic), but with a very different set of metaphors/concepts it's built on. It could be more approachable for normal devs (than Lisps), as its syntax is arguably closer to the mainstream, and the OO metaphor is widely known (although not really understood in a way Smalltalk, Self or Io understand it). Anyway, being able to write functions which can decide whether they want, and how exactly, evaluate their arguments is a powerful technique. I think REBOL and Red are also able to do this, and I think TCL too. Factor would also count, probably. It's a shame it's not supported in more mainstream languages - may be hard to implement efficiently, or may not be that useful with non-homoiconic languages or something like that.

74 points by adgasf 8y ago

orthoxerox 8y ago

I wonder if it's possible to infer the types of a Kernel program.

sparkie 8y ago
Certainly not with our existing type systems. It might be possible if somebody could come up with a new system with the vau calculus at its core rather than lambda calculus (as Hindley-Milner etc. are). I think it would be a dead-end with kernel-standard though. The presence of mutability and cyclic data structures seems like the problem would be as unsolvable as the halting problem. For any serious investigation of type inference, you would probably need to stick to an immutable Kernel subset. The Kernel Report does make mutability optional.
- CuriousSkeptic 8y ago
  Hmm, I don’t see why vau-calculus should change things. Fexpr are more or less like expression trees in C# no? (Which are statically typed, at least where they compose with the rest of the program). Granted, dynamic languages in general can be a challenge, but TypeScript is a good argument for it being feasible at least.

fake-name 8y ago

> The Kernel Programming Language Because no one uses `kernel` for anything already. I mean, holy fucking hell, if you're creating a programming language, choose a name that you can fucking search for.

giancarlostoro 8y ago
I vote they choose Colonel instead if they do any sort of rename.
ummonk 8y ago
I think the next programming language I write will be named the Software Programming Language.
- Midnightas 8y ago
  Mine will be called simply Programming Language.
  - keithalewis 8y ago
    How about A Programming Language https://en.wikipedia.org/wiki/APL_(programming_language) https://en.wikipedia.org/wiki/APL_(programming_language)? Yeah, that's the ticket.
    - adharmad 8y ago
      And a recursive acronym to boot!
    - pgeorgi 8y ago
      Or Programming Language One (https://en.wikipedia.org/wiki/PL/I https://en.wikipedia.org/wiki/PL/I)
  - klyrs 8y ago
    Mine will be a scripting language called Compiler
    - 9dev 8y ago
      Mine will be called lang. The docs can be found on the official website, langlang.org of course.
coldtea 8y ago
>Because no one uses `kernel` for anything already. Because people will seriously be perplexed between an esoteric experimental programming language and operating system kernels, right? Like that huge fiasco in the early 50s, when people confused OS kernels with corn...
- justaaron 8y ago
  no, it's called a "search result"
  - coldtea 8y ago
    We have C, a language named after a letter, and Go, a language named after a verb, and your issue is with "Kernel"? Just fucking add fucking "programming language" as the suffix to your fucking query about Kernel the PL, to mimic the tone of the original comment.
    - fake-name 8y ago
      C, which was named before search engines were a thing, and Go, which is also a terrible name, but google is big enough they can make it work. Also, it's not like things like the linux kernel have a specific enough dialect of C it could be considered a programming dialect/language itself, so there are multiple layers of poor naming here. The point is if you want people to use your esoteric programming language, you want to minimize any blatantly obvious pain points. Choosing a decent name is a very easy pain point to avoid.
    - seandougall 8y ago
      Searching for “kernel programming language” mostly turns up a bunch of results about what programming languages are good for kernel programming. Adding words doesn’t always disambiguate. I mean, it doesn’t turn up any results about corn, so I guess that’s something, but beyond that it doesn’t seem terribly helpful.
- fake-name 8y ago
  People, no. Pretty much every search engine ever? Ohhhhh yeeeaaahhh. Besides, the Linux kernel has a specific-enough dialect of C that I assumed this was about linux kernel programming based on the title.

deleted 8y ago

[deleted]

klibertp 8y ago

The same idea - allowing a procedure to get either a reference to a value or syntactic description of the value coupled with the dynamic environment from the procedure call-site - is implemented in Io language. Io is a purely OO language influenced by Smalltalk and Self the most; it has only objects and no classes, objects have named slots which reference other objects (some of which are "activatable" - callable, IOW - and they're then called methods) and all computation happens by sending messages between objects. If a message name corresponds to the slot name which holds a method, that message send (by default) results in the method being called. Messages are just objects, which carry both dynamic environments from the place they were sent and the arguments, which are passed as message objects themselves. The method may then choose to evaluate some of the messages passed as arguments or not; but it can also change the messages before evaluating them, as the Message objects are mutable and respond to many of the same messages that Lists respond to, including `setAt(idx, val)` for example. (One tricky part of all of this is getting the relation between Message objects and message-sends in Io. In short, Messages are objects which have target, name, and a list of arguments. These objects can be both serialized into, and read from a string, in which case they look like this: target msgName(arg1, arg2, ...) The place in program text and the lexical environment at that point is a message-send, while Message is a runtime representation of that message-send and it references dynamic environment at the point of call. And BTW, in the syntax of message-send above, both `target` and `(arg1, ...)` are optional. In Io, code like this: 1 is, in fact, a message send with `name` set to `"1"`; it's first sent to the current `this` object, and then bubbles up the inheritance chain to `Object`, which handles the message by returning a Number object with value of `1`.) The effect is really interesting: the language is incredibly expressive, with metaprogramming support rivaling Lisp (Io is also homoiconic), but with a very different set of metaphors/concepts it's built on. It could be more approachable for normal devs (than Lisps), as its syntax is arguably closer to the mainstream, and the OO metaphor is widely known (although not really understood in a way Smalltalk, Self or Io understand it). Anyway, being able to write functions which can decide whether they want, and how exactly, evaluate their arguments is a powerful technique. I think REBOL and Red are also able to do this, and I think TCL too. Factor would also count, probably. It's a shame it's not supported in more mainstream languages - may be hard to implement efficiently, or may not be that useful with non-homoiconic languages or something like that.