state-management

import { create } from 'zustand'
import { persist } from 'zustand/middleware'

interface FilterState {
  search: string
  category: string | null

import SwiftUI

struct ContentView: View {
    @State private var username = ""
    @State private var isLoggedIn = false
    @StateObject private var viewModel = LoginViewModel()

/* Interactive pseudo-classes */
a:link { color: blue; }
a:visited { color: purple; }
a:hover { text-decoration: underline; }
a:active { color: red; }
a:focus { outline: 2px solid orange; }

import React, { createContext, useContext, useState, useEffect, ReactNode } from 'react'
import { User } from '@/types'
import api from '@/services/api'

interface AuthContextType {
  user: User | null

<nav id="main-navbar"
     data-turbo-permanent
     data-controller="navbar"
     data-navbar-menu-open-value="false"
     class="navbar">
  <div class="navbar-inner">

export class QueryCache {
  constructor() {
    this.entries = new Map();
  }

  getEntry(key) {

import { useReducer } from 'react'

interface FormState {
  values: Record<string, any>
  errors: Record<string, string>
  touched: Record<string, boolean>

import { useMemo } from "react";

export type SortDir = "asc" | "desc";
export interface SortConfig<T> {
  key: keyof T;
  dir: SortDir;

import React from 'react'
import ReactDOM from 'react-dom/client'
import { QueryClient, QueryClientProvider } from '@tanstack/react-query'
import { ReactQueryDevtools } from '@tanstack/react-query-devtools'
import App from './App'
import './index.css'

import { useEffect, useState } from "react";

export function useDebouncedValue(value, delay = 300) {
  const [debounced, setDebounced] = useState(value);

  useEffect(() => {

export const initialCart = { items: {} };

export function cartReducer(state, action) {
  switch (action.type) {
    case 'ADD_ITEM': {
      const { product, qty = 1 } = action;

export interface Todo {
  id: string;
  title: string;
  done: boolean;
  pending: boolean;
}