Advanced Lambda Concepts

Master powerful functional programming patterns and advanced optimizations in Lambda.

Monad Transformers

Stackable Effects

Combine error handling with state management using monad transformers: 


const StateMaybe = new StateTransformer(Maybe);

const safeCounter = StateMaybe.of(0)
    .map(state => state + 1); 

safeCounter.run(); 
// { state: 1, value: Maybe.Just(1) }

Functor Composition

Map Over Nested Structures

Array(Future(Maybe).of(5))
    .map(x => x * 2)
    .get(); // Returns 10 or null
Contravariant Functors

const validator = contramap(parseInt)
    .compose(String)
    .contramap(Date.parse);

📘 Applicative Functors

  • Parallel Validation: validateUser and validatePassword can be executed concurrently.
  • Non-Empty Results: Always returns an array of errors, even if none exist.
  • Type-safe Validation: Built-in type guards ensure only valid data is processed. 

const ValidationApplicative = Applicative.of(validate);
const validateForm = Applicative.liftA2(
    (credentials) => credentials, 
    ValidationApplicative("email", emailVal),
    ValidationApplicative("password", passwordVal)
);

🔍 Lens Combinators

Access Deep Nested Data

const userLens = lens(['profile', 'settings']);
const newUserValue = set(userLens, { theme: 'dark' }, state);
Immutable Updates

const updated = over(
    lensPath(['data', 'items']),
    item => ({ ...item, status: 'processed' }),
    original
);
Validation

const emailLens = lensProp('email');
const validateEmail = compose(
    view(emailLens),
    formatValidationResult
);

⚡ Performance Optimizations

Smart Memoization

Caches function results based on input types: 


const optimizedMap = memoizeWith(
    (fn, arr) => typeKey(fn) + hashArray(arr)
);
Tail Recursion Optimization

Prevents stack overflows in complex chains: 


const trReduce = (fn, acc, arr) => {
    if (arr.length === 0) return acc;
    return trReduce(fn, fn(acc, arr[0]), arr.slice(1));
};
Lazy Evaluation

Delay computation until necessary: 


const lazy = deferral(() => {
    const startTime = Date.now();
    while (Date.now() - startTime < 1000) {}
    return "Computed Value";
});
🔧 API Reference
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