add-type-support

name	add-type-support
description	Add support for a new type to unify and clone registries. Use when asked to support a new JavaScript type or custom class in deep6.

Add Type Support to deep6

Add support for a new type to the unification and cloning registries.

Steps

1. Identify the type — Determine what type needs support (built-in or custom class).

2. Read existing patterns — Check src/unify.js and src/traverse/clone.js for how similar types are handled.

3. Add unifier to src/unify.js:

   • Create a comparison function: (l, r, ls, rs, env) => boolean
   • Return true for match, false for failure
   • Push child values to ls/rs for recursive comparison
   • Add to registry: registry.push(Type, compareFunction)

4. Add cloner to src/traverse/clone.js:

   • Create a processor function: (val, context) => void
   • Push cloned value to context.stackOut
   • Add to registry: registry.push(Type, processorFunction)

5. Add tests in tests/tests.js:

   • Test equality with equal()
   • Test cloning with clone()
   • Test edge cases

6. Run tests: npm test

7. Update documentation:

   • Add to llms.txt and llms-full.txt
   • Update ARCHITECTURE.md if needed

Example: Adding Date Support

Unifier (src/unify.js):

registry.push(Date, (l, r) => l instanceof Date && r instanceof Date && l.getTime() == r.getTime());

Cloner (src/traverse/clone.js):

registry.push(Date, (val, context) => context.stackOut.push(new Date(val.getTime())));

Example: Adding Set Support

Unifier (src/unify.js):

const unifySet = (l, r, ls, rs, env) => {
  if (!(l instanceof Set) || !(r instanceof Set) || l.size != r.size) return false;
  for (const item of l) {
    if (!r.has(item)) return false;
  }
  return true;
};
registry.push(Set, unifySet);

Cloner (src/traverse/clone.js):

registry.push(Set, (val, context) => context.stackOut.push(new Set(val)));

Typed Arrays Pattern

For typed arrays, use a factory function:

const unifyTypedArrays = Type => (l, r, ls, rs, env) => {
  if (!(l instanceof Type) || !(r instanceof Type) || l.length != r.length) return false;
  for (let i = 0; i < l.length; ++i) {
    if (l[i] != r[i]) return false;
  }
  return true;
};

typeof Int8Array == 'function' && addType(Int8Array);

Custom Class Pattern

For custom classes, extend Unifier:

import {Unifier} from 'deep6/env.js';

class MyClassMatcher extends Unifier {
  unify(val, ls, rs, env) {
    if (!(val instanceof MyClass)) return false;
    // Compare properties
    ls.push(this.value);
    rs.push(val.value);
    return true;
  }
}

Conventions

• Keep comparison functions concise
• Handle edge cases (null, undefined, wrong type)
• Use instanceof for type checking
• Push child values to stacks for deep comparison
• Follow existing code style (2-space indent, semicolons required)