Transform multi-argument functions into chained calls and combine small functions into pipelines.
curry functions.pipe helper to construct left-to-right processing streams matching natural reading orders.Currying chainsConverts multi-argument functions into sequential single-argument calls.
function add(a, b, c) {
return a + b + c;
}
const curryAdd = a => b => c => a + b + c;
curryAdd(1)(2)(3); // 6Call executionInvokes the original function only after all arguments are received.
const add5 = curryAdd(5);
add5(2)(3); // 10Arrow notationUses nested arrow functions to construct inline curried definitions.
const multiply = a => b => a * b;curry() implementationGathers arguments recursively until the count matches function arity.
function curry(fn) {
return function curried(...args) {
if (args.length >= fn.length) {
return fn.apply(this, args);
}
return (...next) => {
return curried.apply(this, [...args, ...next]);
};
};
}Function lengthResolves function arity dynamically using the fn.length property.
const sum = curry((a, b, c) => a + b + c);
sum(1)(2)(3); // 6
sum(1, 2)(3); // 6Arity configurationsSpecifies manual arity limits for functions with default parameters.
function curryN(fn, arity) {
return function collect(...args) {
return args.length >= arity
? fn(...args)
: (...more) => collect(...args, ...more);
};
}bind() methodBinds arguments up front using the built-in prototype bind method.
function mult(a, b) { return a * b; }
const double = mult.bind(null, 2);
double(5); // 10Custom partialBuilds a partial helper to bind arguments without bind context.
function partial(fn, ...fixed) {
return (...rest) => fn(...fixed, ...rest);
}
const greet = partial((g, n) => g + n, "Hi ");
greet("Ada"); // "Hi Ada!"compose() helperCombines functions executing right-to-left like mathematical equations.
const compose = (...fns) => x =>
fns.reduceRight((acc, f) => f(acc), x);
const shout = s => s.toUpperCase() + "!";
const format = compose(shout, s => s.trim());
format(" hi "); // "HI!"pipe() helperCombines functions executing left-to-right to match reading order.
const pipe = (...fns) => x =>
fns.reduce((acc, f) => f(acc), x);
const run = pipe(s => s.trim(), s => s.toUpperCase());
run(" hi "); // "HI"Curried validationPre-fills validation parameters to generate specialized rule checklists.
const minLength = curry((min, s) => s.length >= min);
const isValid = minLength(3);
isValid("ok"); // falseMiddleware executionThreads orders or values through sequential modifier function lists.
const processOrder = pipe(
applyDiscount,
addTax
);
processOrder(100);Currying transforms a function to accept one argument per call sequentially. Partial application binds multiple arguments immediately and returns a function waiting for the remaining parameters.
Inspect target function arity using the length property. Recursively gather arguments until they match or exceed that length, then invoke the underlying function.
Both helpers chain functions together. Compose executes functions from right to left. Pipe executes them from left to right, matching sequential reading order.
Currying enables specialized helper construction by pre-filling configuration values. This reduces duplicate parameters and allows seamless integration inside pipeline composition chains.
Curried calls instantiate closure environments and nested calls. The performance cost is usually negligible. Avoid currying inside critical performance paths like tight execution loops.
Order Processing Pipeline
Pairs a curried discount calculator with a left-to-right pipeline to process invoice figures.
const curry = fn => (...args) =>
args.length >= fn.length
? fn(...args)
: (...more) => curry(fn)(...args, ...more);
const applyDiscount = curry((rate, price) =>
price * (1 - rate)
);
const applyTenPercentOff = applyDiscount(0.1);
const addTax = price => price * 1.08;
const format = price => "$" + price.toFixed(2);
const pipe = (...fns) => x =>
fns.reduce((acc, fn) => fn(acc), x);
const processOrder = pipe(
applyTenPercentOff,
addTax,
format
);
console.log(processOrder(100)); // "$97.20"Pre-filling function parameters with currying yields simple unary steps that pipe links together smoothly.