eyg_compile

EYG compiler that transpiles to JavaScript.

gleam add eyg_compiler

import eyg/compiler
import eyg/ir/tree as ir
import gleam/dict

pub fn main() {
  let source = ir.let_("x", ir.integer(5), ir.variable("x"))
  let refs = dict.new()
  compiler.to_js(source, refs)
  // let x$0 = 5;
  // x$0
}

Further documentation can be found at https://hexdocs.pm/eyg_compile.

Development

gleam run
gleam test

Notes

Compilation path follows two main resources.

• MinCaml
• Generalized Evidence Passing for Effect Handler
  • Long version (https://www.microsoft.com/en-us/research/uploads/prod/2021/03/multip-tr-v4.pdf)

The current implementation uses a js version of a monad, something is an instance of an Eff or not. If not is is assumed a value. This is similar to thinking of value or null being an Option.

This allows the transpiled JS to look as similar as possible to the original source. There is no lambda lifting or closure conversion and there is no global yielding variable. These are not necessary when relying on the dynamism of JS.

Such an implementation is ineffecient as it always bubbles the effect, there is no evidence passing. A future version could add the evidence vector and other optimisation, however:

• readability would be effected.
• performance should not be sort before measurement.
• A fast interpreter with flat AST may be faster and simpler.

It’s probably worth considering what compilation to tiny go or an arduino interpreter looks like.

• Is there a way to check for tail resumption if handler is passed as var and not AST? This is needed if trying to optimise away bubbling in the general case