// re-inventing the wheel:
export function deepEqual(a, b) {
  if (a === b) return true; // <- shallow equality and primitives
  if (typeof a !== 'object' || typeof b !== 'object' || a === null || b === null) {
    return false;
  }
  if (Array.isArray(a) && Array.isArray(b)) {
    if (a.length !== b.length) return false;
    for (let i = 0; i < a.length; i++) {
      if (!deepEqual(a[i], b[i])) return false;
    }
    return true;
  }
  const keysA = Object.keys(a);
  const keysB = Object.keys(b);
  if (keysA.length !== keysB.length) return false;
  for (let key of keysA) {
    if (!keysB.includes(key) || !deepEqual(a[key], b[key])) {
      return false;
    }
  }
  return true;
}

// zip two arrays
export function zip(a, b) {
  return a.map((k, i) => [k, b[i]]);
}

export class DefaultMap {
  constructor(defaultValue, ...rest) {
    this.defaultValue = defaultValue;
    this.m = new Map(rest);
  }
  getdefault(key, addToMapping=false) {
    return this.m.get(key) || (() => {
      const val = this.defaultValue(key);
      if (addToMapping)
        this.m.set(key, val);
      return val;
    })();
  }
  entries() {
    return this.m.entries();
  }
}


import { inspect } from 'node:util';
import { symbolFunction, symbolList, symbolProduct, symbolSum } from './structures/types.js';

export function pretty(obj) {
  return inspect(obj, {colors: true, depth: null});
}

export function prettyT(type) {
  if (type.typeVars) {
    return `∀${[...type.typeVars].map(prettyT).join(", ")}: ${prettyT(type.type)}`;
  }
  if (type.symbol === symbolFunction) {
    return `${prettyT(type.params[0])} -> ${prettyT(type.params[1])}`;
  }
  if (type.symbol === symbolList) {
    return `[${prettyT(type.params[0])}]`;
  }
  if (type.symbol === symbolProduct) {
    return `(${prettyT(type.params[0])}, ${prettyT(type.params[1])})`;
  }
  if (type.symbol === symbolSum) {
    return `(${prettyT(type.params[0])} | ${prettyT(type.params[1])})`;
  }
  if (type.params.length === 0) {
    return type.symbol.description;
  }
  return `${type.symbol.description}(${type.params.map(prettyT).join(", ")})`;
}