Tianzhen Lin (Tangent) tangentlin

tangentlin / credit-card-entry-declarative-processing.ts

Created March 31, 2024 01:29

	function validateAndFormatCard(number: string, type: string) {
	const cardType = creditCardTypes[type];
	if (!cardType) {
	throw new Error('Unsupported card type');
	}
	const isValid = cardType.validate(number);
	const formattedNumber = cardType.format(number);
	return {
	isValid,
	formattedNumber,

tangentlin / credit-card-entry-declarative.ts

Created March 31, 2024 01:27

	interface CreditCardType {
	name: string;
	logoUri: string;
	validate: (number: string) => boolean;
	format: (number: string) => string;
	}

	const creditCardTypes: Record<string, CreditCardType> = {
	visa: {
	name: "Visa",

tangentlin / credit-card-processing-declarative.ts

Created March 31, 2024 01:24

A contrived declarative approach of declarative programming

	interface PaymentMethod {
	process(amount: number): void;
	}

	const paymentMethods: Record<string, PaymentMethod> = {
	credit: {
	process(amount: number) {
	console.log(`Processing $${amount} via Credit Card`);
	// Credit card processing logic...
	}

tangentlin / credit-card-processing-imperative.ts

Created March 31, 2024 01:20

Imperative programming example

	function processPayment(amount: number, method: string) {
	switch (method) {
	case 'credit':
	// Process credit card payment
	break;
	case 'paypal':
	// Process PayPal payment
	break;
	case 'bank_transfer':
	// Process bank transfer