bluebird VS pika

0 upto n and 0 thru n. I think I saw it in Bluebird first and really liked it.

Instead of the classic visitor pattern, I found it easier to create a class that basically wraps a big switch statement that switches on an enum representing the kind of expression. You pass it an expression, and based on the enum returned by its kind() function you downcast the expression into the subclass you need. The code is here for reference. My AST code is here.

I am working some again on my Ada-like language bluebird. I am making another attempt to use MLIR as an intermediate IR between the AST and LLVM IR (I made a brief attempt a few months ago just to look into it).

I fworked some more towards adding pointers on my Ada-like programming language bluebird. I've finished adding pointer types and variables (as well as the operators for dereferencing/getting the address of objects), but I still need to add the ability to dereference and assign.

I started to experiment with using MLIR to write a high-level IR for my language bluebird, which will hopefully reduce the work of implementing features I want to add such as generics and ranges, as well as allowing me to eventually write some optimizations. I am also considering rewriting my AST as an MLIR dialect, since MLIR provides a bunch of type-checking/error printing/support infrastructure.

I continued implementing support for references (a restricted form of pointers) in my Ada-like language bluebird. I also am working on adding a cleanup pass between my parser/typechecker to handle stuff like type resolution of literals and constant folding.

I didn’t add too many new features to my Ada-like language bluebird this month because of lots of projects/school stuff.

Here is a link to my optimizer pass setup for reference. This is just a simple optimization pipeline (I think clang has a setup where optimization stages are re-run multiple times to take advantage of inlining making more optimizations possible).

I made some more progress on bluebird, my Ada-like language.

I continued to make progress on the compiler for my Ada-inspired language bluebird. I will have less time to spend on it as classes began earlier last month, but I still hope to continue working on it. Things are getting to the point where adding a new feature isn’t as difficult as it was when doing so often meant writing the supporting code from nothing.

I just switched Pika to using significant indentation. This is mostly because of how annoying line continuation is in a ML-style language (so f a b syntax) without significant indentation or required semicolons, but you can read more about the reasons for that decision in this section of the README.

Recently, I've been working on adding garbage collection to Pika. I've successfully written an Immix-based garbage collector that works with the LLVM GC support infrastructure, and I'm currently working on integrating the GC with Pika, or really Durin, the dependently-typed intermediate representation that Pika compiles to. Because types are passed around at runtime, objects of unknown type and size can be stored unboxed in polymorphic data structures; but that makes keeping track of type information for heap allocations somewhat harder, because type information needs to be allocated and constructed at runtime in some cases. It's an interesting design problem, because you want constructing type information to be fast; but the GC will run much more often, so maximizing tracing speed by avoiding e.g. indirection in type information is important; and you also want to construct as much type information as possible at compile time and embed it as constants.

I've been working on adding algebraic effects to Pika during the past month. It's turned out to be harder than I thought it would, but I'm almost done - performing and catching one effect at a time works, and the compilation strategy I'm using now (I reimplemented the whole thing after realizing the strategy I was using wouldn't actually work) should be enough to handle multiple effects at once and also effect polymorphism, I just have to get those working in the elaborator.

After taking a break from Pika, my dependently-typed ML for systems programming, during the month of January, I've started working on it again by getting recursion to work properly. I'm planning on starting to implement algebraic effects next, and an Immix-based garbage collector for boxed values after that. Here's what my current plan for algebraic effects looks like: