paiza.template.js

const fn = value => {
  return value
}

// main function
;((stdin, stdout) => {
  // input
  const value = stdin('/etc/passwd').readStream()
  // call function
  const result = fn(value)
  // output
  stdout(result).toStream()
})(std().in, std().out)

function std () {
  const identity = value => value
  return {
    in: (file = '/dev/stdin') => {
      const split =
        (sep = ' ') =>
        string =>
          string.split(sep)
      const toArray = sep => fn => iter => Array.from(split(sep)(iter), fn)
      const stream = require('fs').readFileSync(file, 'utf-8').toString().trim()
      return {
        readCols: (fn = identity) => toArray(' ')(fn)(stream),
        readRows: (fn = identity) => toArray('\n')(fn)(stream),
        readStream: (fn = identity) => fn(stream),
        readMatrix: (fn = identity) =>
          toArray('\n')(identity)(stream).map(toArray(' ')(fn))
      }
    },
    out: value => {
      const _p = fn => value => console.log(fn(value))
      const join =
        (sep = '\n') =>
        array =>
          array.join(sep)
      return {
        toCols: () => _p(join(' '))(value),
        toRows: () => _p(join('\n'))(value),
        toJSON: () => _p(JSON.stringify)(value),
        toStream: () => _p(identity)(value),
        toMatrix: () => _p(join('\n'))(value.map(join(' ')))
      }
    }
  }
}