• additional types: bigint

• can serialize/deserialize without reading source code
  • no function serialization/deserialization

A DJS module parses into ast/module.f.mjs; the types in ast/types.ts carry the shape and its invariants.

Why a flat list of constants with index references, rather than a value tree: a DJS module denotes a graph, and import and const are how it names the shared parts. Deserializing has to preserve that sharing — two properties holding the same reference must yield the same object, not two equal copies — so the AST keeps the constants addressable and refers to them by index instead of inlining them. That is also what makes serialization a real choice: a value referenced more than once is emitted as a const and reused. See examples/input.f.mjs.

• use JS tokenizer
• identifiers {a:5}
• computed keys {["a"]:5}, the only spelling of a __proto__ key (spec: the __proto__ key)
• big int
• export default ...
• constants

  const a = [3]
  export default = { a: a, b: a }

  Serialization

  const _0=[3]
  export default {a:_0,b:_0}

• import

  import a from 'c.f.js'
  export default { a: a, b: a}

• short form

  const a = 5;
  export default { a }

Optional, for fun, syntax sugar:

• comments. Ignore them. Not an error.
• double/single quote strings

• using operator and functions

  const a = 2+2+Math.abs(5)
  export default { a: a }

• decidable functions?

  const f = a => b => a + b
  export default f(1)(2)