functioner/src/crypto.js

A node.js module containing a set of higher order functions

'use strict';

var crypto = {

  caesar: function(x) {
    if (x < 0) {
      x = x + 26;
    }
    return function(string) {
      var output = '';

      Array.from(string).forEach(char => {
        if (char.match(/[a-z]/i)) {
          var code = char.charCodeAt(0);

          if (code >= 65 && code <= 90) {
            char = String.fromCharCode(((code - 65 + x) % 26) + 65);
          } else if (code >= 97 && code <= 122) {
            char = String.fromCharCode(((code - 97 + x) % 26) + 97);
          }
        }

        output +=  char;
      });

      return output;
    };
  },

  compose: function() {
    var fns = Array.from(arguments);
    return function(val) {
      for (let i = fns.length - 1; i >= 0; i--) {
        val = fns[i](val);
      }
      return val;
    };
  },
  
  accessor: function(access) {
    return function(obj) {
      return obj[access];
    };
  },

  index: function(i) {
    return function(arr) {
      return arr[i];
    };
  },

  print: function(val) {
    console.log(val);
  }
};

module.exports = crypto;