Virgil Alternatives

virgil reviews and mentions

• Garbage Collection for Systems Programmers
  7 projects | news.ycombinator.com | 30 Mar 2024

  For (2) Virgil has several features that allow you to layout memory with various levels of control. I assume you meaning "array of structs", and you can do that with arrays of tuples, which will naturally be flattened and normalized based on the target (i.e. will be array-of-structs on native targets). You can define byte-exact layouts[1] (mostly for interfacing with other software and parsing binary formats), unbox ADTs, and soon you can even control the exact encoding of ADTs.

  Virgil is GC'd.

  [1] https://github.com/titzer/virgil/blob/master/doc/tutorial/La...

• The Return of the Frame Pointers
  6 projects | news.ycombinator.com | 17 Mar 2024

  Virgil doesn't use frame pointers. If you don't have dynamic stack allocation, the frame of a given function has a fixed size can be found with a simple (binary-search) table lookup. Virgil's technique uses an additional page-indexed range that further restricts the lookup to be a few comparisons on average (O(log(# retpoints per page)). It combines the unwind info with stackmaps for GC. It takes very little space.

  The main driver is in (https://github.com/titzer/virgil/blob/master/rt/native/Nativ... the rest of the code in the directory implements the decoding of metadata.

  I think frame pointers only make sense if frames are dynamically-sized (i.e. have stack allocation of data). Otherwise it seems weird to me that a dynamic mechanism is used when a static mechanism would suffice; mostly because no one agreed on an ABI for the metadata encoding, or an unwind routine.

  I believe the 1-2% measurement number. That's in the same ballpark as pervasive checks for array bounds checks. It's weird that the odd debugging and profiling task gets special pleading for a 1% cost but adding a layer of security gets the finger. Very bizarre priorities.

• Whose baseline (compiler) is it anyway?
  1 project | news.ycombinator.com | 27 May 2023

  This paper is the first time I seen mention of the Virgil programming language, from the same author:

  https://github.com/titzer/virgil

• JEP 450: Compact Object Headers
  2 projects | news.ycombinator.com | 4 May 2023

  JavaScript handles the "no identity hash" with WeakMap and WeakSet, which are language built-ins. For Virgil, I chose to leave out identity hashes and don't really regret it. It keeps the language simple and the separation clear. HashMap (entirely library code, not a language wormhole) takes the hash function and equality function as arguments to the constructor.

  [1] https://github.com/titzer/virgil/blob/master/lib/util/Map.v3

  This is partly my style too; I try to avoid using maps for things unless they are really far flung, and the things that end up serving as keys in one place usually end up serving as keys in lots of other places too.

• Retrofitting null-safety onto Java at Meta
  4 projects | news.ycombinator.com | 22 Nov 2022

  Whoa, interesting. I didn't know Kotlin had all those constructs.

  In Virgil, a method on an object (or ADT) can declare its return type as "this". Then the method implicitly returns the receiver object. That trick is very useful to allow a chain of calls such as object.foo().bar().baz(). I find it readable and easy to explain:

  https://github.com/titzer/virgil/blob/master/doc/tutorial/Re...

• A Ruby program that generates itself (through a 128-language quine loop)
  9 projects | news.ycombinator.com | 6 Oct 2022

  I hadn't written one until ~30 mins ago [1]. I cheated and looked at a Java quine (not particularly elegant, but easy to see what is going on.), but I wrote one for Virgil. Just think string substitution; a string with a hole in it and you substitute a copy of the string, quoted into the hole. Just one substitution suffices.

  [1] https://github.com/titzer/virgil/blob/master/apps/Quine/Quin...

• Integer Conversions and Safe Comparisons in C++20
  1 project | news.ycombinator.com | 13 Sep 2022

  Virgil has a family of completely well-defined (i.e. no UB) fixed-size integer types with some hard-fought rules that I eventually got around to documenting here:

  https://github.com/titzer/virgil/blob/master/doc/tutorial/Fi...

  One of the key things is that values are never silently truncated (other than 2's-complement wrap-around) or values changed; only promotions. The only sane semantics for over-shifts (shifts larger than the size of the type) is to shift the bits out, like a window.

  The upshot of all that is that Virgil has a pretty sane semantics for fixed-size integers, IMHO.

• Show HN: We are trying to (finally) get tail-calls into the WebAssembly standard
  11 projects | news.ycombinator.com | 12 Jul 2022

  LLVM and other compilers that use SSA but target a stack machine can run a stackification phase. Even without reordering instructions, it seems to work well in practice.

  In Virgil I implemented this for both the JVM and Wasm. Here's the algorithm used for Wasm:

  https://github.com/titzer/virgil/blob/master/aeneas/src/mach...

• Hacker News top posts: Jul 2, 2022
  2 projects | /r/hackerdigest | 2 Jul 2022

  Virgil: A fast and lightweight programming language that compiles to WASM\ (54 comments)

• Virgil: A fast and lightweight programming language that compiles to WASM
  1 project | /r/hypeurls | 1 Jul 2022
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