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FunctionalProgrammingadvanced

Compose vs pipe equivalence

📖 Usage Example
const compose = (...fns) => x => fns.reduceRight((v, f) => f(v), x);
const pipe = (...fns) => x => fns.reduce((v, f) => f(v), x);
// compose(g, h)(x) === pipe(h, g)(x)

compose(g, h) and pipe(h, g) produce the same result — they differ only in order.

Comparing Compose and Pipe

Compose and pipe do the same thing but in opposite orders. Their composed results should be equivalent when used correctly.

Challenge: Prove that compose(f, g)(x) equals pipe(g, f)(x) by implementing both and testing their equivalence.

💡 Hints (3)
  • • compose(f, g) reads right-to-left: apply g first, then f
  • • pipe(g, f) reads left-to-right: apply g first, then f
  • • They are mirrors of each other