Postfix-ish javascript (single argument)
function pipe (A) { return (f) => { mutable count += 1 // (log when this function is evaluated) if (!f) return A return pipe(f(A)) } } // can be written briefly as f = A => g => g ? A : f(g(A)) // Usage: // pipe(object)(a => b)(b => c)...(y => z)() // returns z // useful for declarative programming pipelines
pipe('a') (a => a + 'b') (b => b + 'c') (c => c + 'd') ()
{ // function evaluations are immediate, so we don't have to worry about stack overflow mutable count = 0 const pipeline = pipe('a') (a => a + 'b') (b => b + 'c') (c => c + 'd') const prior_evaluations = mutable count mutable count = 0 const output = pipeline() const final_evaluations = mutable count return [prior_evaluations, final_evaluations] }
mutable count = 0