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examples

README.md

Examples

This directory contains comprehensive examples demonstrating the usage of @mcabreradev/filter v5.1.0.

Running Examples

TypeScript Examples

To run the TypeScript examples with ts-node:

pnpm install -g ts-node
ts-node examples/operators-examples.ts

Compiled Examples

  1. Build the project:

    pnpm run build

  2. Compile the examples:

    tsc examples/operators-examples.ts --outDir examples/dist --esModuleInterop

  3. Run the compiled example:

    node examples/dist/operators-examples.js

Available Examples

array-or-syntax-examples.ts (v5.4.0+)

Comprehensive examples showcasing the new array OR syntax (syntactic sugar for $in):

  • Basic Array Syntax: Using arrays for OR logic on property values
  • Equivalence with $in: Demonstrating that array syntax equals explicit $in operator
  • AND + OR Combination: Combining array OR logic with other AND conditions
  • Multiple Array Properties: Using arrays on multiple properties independently
  • Wildcard Support: Using wildcards (%, _) within array values
  • Type Support: Examples with strings, numbers, booleans
  • Edge Cases: Empty arrays, single-element arrays
  • Complex Filtering: Multi-condition queries with array syntax
  • Real-World Use Cases: E-commerce, user management, analytics examples

autocomplete-demo.ts

Interactive examples demonstrating intelligent autocomplete for operators:

  • Type-Based Suggestions: TypeScript suggests only valid operators for each property type
  • Number Operators: Autocomplete for $gt, $gte, $lt, $lte, $eq, $ne
  • String Operators: Autocomplete for $startsWith, $endsWith, $contains, $regex, $match
  • Array Operators: Autocomplete for $in, $nin, $contains, $size
  • Boolean Operators: Autocomplete for $eq, $ne
  • Date Operators: Autocomplete for date comparison operators
  • Combined Examples: Multiple operators with intelligent suggestions

nested-autocomplete-demo.ts

Advanced examples showcasing autocomplete for deeply nested objects:

  • Multi-Level Nesting: Autocomplete works up to 4 levels deep
  • Level 2 Filtering: Filter by nested object properties (e.g., address.city)
  • Level 3 Filtering: Filter by deeply nested properties (e.g., address.coordinates.lat)
  • Level 4 Filtering: Filter by very deeply nested properties (e.g., settings.privacy.showEmail)
  • Complex Queries: Combine multiple nested levels in a single query
  • Logical Operators: Use $or, $and, $not with nested objects
  • Mixed Syntax: Combine direct values and operators at different levels
  • Real-World Examples: Practical use cases with nested data structures

operators-examples.ts

Comprehensive examples showcasing all v5.0.0 operators:

  • Comparison Operators: $gt, $gte, $lt, $lte, $eq, $ne
  • Array Operators: $in, $nin, $contains, $size
  • String Operators: $startsWith, $endsWith, $contains
  • Combined Operators: Multiple operators on same/different properties
  • Mixed Syntax: Operators combined with legacy v3.x syntax
  • Real-World Scenarios: E-commerce, inventory, and search use cases

lazy-evaluation-examples.ts (v5.1.0+)

Comprehensive examples showcasing lazy evaluation features:

  • Basic Lazy Filtering: Using filterLazy for on-demand processing
  • Early Exit Optimization: Using filterFirst to stop after N matches
  • Existence Checks: Using filterExists for fast boolean checks
  • Counting: Using filterCount without creating result arrays
  • Chunked Processing: Using filterChunked and filterLazyChunked for batch operations
  • Lazy Composition: Combining take, skip, map, and other utilities
  • Pagination: Building efficient pagination with lazy operations
  • Async Streams: Using filterLazyAsync for async iterables
  • Performance Comparison: Benchmarking lazy vs standard filtering
  • Memory Efficiency: Demonstrating memory savings with large datasets

memoization-examples.ts (v5.2.0+)

Comprehensive examples showcasing the multi-layer memoization strategy:

  • Basic Result Caching: Demonstrating 530x speedup with cached results
  • Predicate Caching: Reusing compiled predicates across different arrays
  • Regex Pattern Caching: Automatic caching of compiled regex patterns
  • Cache Statistics: Monitoring cache size and effectiveness
  • Complex Query Caching: Caching nested and complex expressions
  • Lazy + Cache Combination: Combining lazy evaluation with caching
  • Cache Management: Clearing caches and managing memory
  • Performance Comparison: Benchmarking with/without caching (100 iterations)

Example Output

Running operators-examples.ts will output filtered results for 20 different scenarios, demonstrating:

  1. Price range filtering
  2. Date-based filtering
  3. Category inclusion/exclusion
  4. Tag-based searching
  5. Name pattern matching
  6. Complex multi-condition queries
  7. Performance optimization patterns

Memoization Examples

Basic Result Caching

import { filter } from '@mcabreradev/filter';

const products = [
  { id: 1, name: 'Laptop', price: 1200, category: 'Electronics' },
  { id: 2, name: 'Mouse', price: 25, category: 'Electronics' },
  { id: 3, name: 'Desk', price: 300, category: 'Furniture' },
];

console.time('first');
const electronics1 = filter(
  products,
  { category: 'Electronics' },
  { enableCache: true }
);
console.timeEnd('first');

console.time('cached');
const electronics2 = filter(
  products,
  { category: 'Electronics' },
  { enableCache: true }
);
console.timeEnd('cached');

Predicate Caching Across Arrays

import { filter } from '@mcabreradev/filter';

const users1 = [/* 5,000 users */];
const users2 = [/* 3,000 different users */];
const query = { age: { $gte: 18 }, active: true };

filter(users1, query, { enableCache: true });

filter(users2, query, { enableCache: true });

Regex Pattern Caching

import { filter } from '@mcabreradev/filter';

const users = [/* users */];
const customers = [/* customers */];
const admins = [/* admins */];

const emailPattern = { email: { $regex: '^[a-z]+@example\\.com$' } };

filter(users, emailPattern);

filter(customers, emailPattern);
filter(admins, emailPattern);

Cache Management

import { filter, clearFilterCache, getFilterCacheStats } from '@mcabreradev/filter';

const data = [/* large dataset */];

filter(data, { status: 'active' }, { enableCache: true });

const stats = getFilterCacheStats();
console.log('Predicates cached:', stats.predicateCacheSize);
console.log('Regex patterns cached:', stats.regexCacheSize);

clearFilterCache();

Real-World: E-commerce Dashboard

import { filter, clearFilterCache } from '@mcabreradev/filter';

interface Product {
  id: string;
  name: string;
  category: string;
  price: number;
  inStock: boolean;
  rating: number;
}

class ProductDashboard {
  private products: Product[];

  constructor(products: Product[]) {
    this.products = products;
  }

  getElectronics(): Product[] {
    return filter(
      this.products,
      { category: 'Electronics' },
      { enableCache: true }
    );
  }

  getAffordable(): Product[] {
    return filter(
      this.products,
      { price: { $lte: 100 }, inStock: true },
      { enableCache: true }
    );
  }

  getTopRated(): Product[] {
    return filter(
      this.products,
      { rating: { $gte: 4.5 } },
      { enableCache: true }
    );
  }

  refreshData(newProducts: Product[]): void {
    this.products = newProducts;
    clearFilterCache();
  }
}

const dashboard = new ProductDashboard(products);

dashboard.getElectronics();
dashboard.getAffordable();
dashboard.getTopRated();

dashboard.getElectronics();
dashboard.getAffordable();
dashboard.getTopRated();

Combining Caching with Lazy Evaluation

import { filterFirst, filter } from '@mcabreradev/filter';

const customers = [/* 1,000,000 customers */];

const highValueQuery = {
  totalPurchases: { $gte: 10000 },
  status: 'active',
  lastPurchase: { $gte: thirtyDaysAgo }
};

const top20 = filterFirst(
  customers,
  highValueQuery,
  20,
  { enableCache: true }
);

const top20Again = filterFirst(
  customers,
  highValueQuery,
  20,
  { enableCache: true }
);

Performance Monitoring

import { filter, getFilterCacheStats, clearFilterCache } from '@mcabreradev/filter';

class PerformanceMonitor {
  private queryCount = 0;
  private cacheHits = 0;

  query<T>(data: T[], expression: any): T[] {
    this.queryCount++;

    const startTime = performance.now();
    const result = filter(data, expression, { enableCache: true });
    const endTime = performance.now();

    if (endTime - startTime < 0.1) {
      this.cacheHits++;
    }

    return result;
  }

  getStats() {
    const cacheStats = getFilterCacheStats();
    return {
      totalQueries: this.queryCount,
      cacheHits: this.cacheHits,
      hitRate: (this.cacheHits / this.queryCount * 100).toFixed(2) + '%',
      predicateCacheSize: cacheStats.predicateCacheSize,
      regexCacheSize: cacheStats.regexCacheSize
    };
  }

  reset() {
    this.queryCount = 0;
    this.cacheHits = 0;
    clearFilterCache();
  }
}

const monitor = new PerformanceMonitor();

monitor.query(products, { category: 'Electronics' });
monitor.query(products, { category: 'Electronics' });
monitor.query(products, { price: { $gte: 100 } });

console.log(monitor.getStats());

Further Reading