StarSemigroupoid.js

const {
  curry, isNumber, pipeS, prop, safeLift, Star
} = require('../crocks')

const add = curry(
  (x, y) => x + y
)

const pull =
  x => Star(prop(x))

const safeAdd =
  x => Star(safeLift(isNumber, add(x)))

const data = {
  num: 56,
  string: '56'
}

const flow = (key, num) => pipeS(
  pull(key),
  safeAdd(num)
)

flow('num', 10).runWith(data)
// => Just 66

flow('string', 100).runWith(data)
// => Nothing