env

This module defines the environment and variable-related objects. It is available like that:

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

The following objects are defined:

• EnvLike — the method contract every environment implementation satisfies (TypeScript-only type).
• EnvMap — the Map-stack implementation, the default used by unify() when no environment is passed; lives in deep6/env-map.js.
• Env — the proto-chain sibling implementation.
• Unifier — an interface for custom unifiers.
  • isUnifier(x) — returns a truthy value for objects based on Unifier.
• Variable — a class to create variable objects that can be used with any EnvLike environment.
  • isVariable(x) — returns a truthy value for objects based on Variable.
  • variable([name]) — creates a variable object.
• any (or _) — special object that matches anything.

Shared primitives (Unifier, Variable, _, any and their helpers) also live in deep6/env-shared.js. Both deep6/env.js and deep6/env-map.js re-export them, so existing import {…} from 'deep6/env.js' keeps working unchanged.