pegjs/lib/utils/arrays.js

"use strict";

/* Array utilities. */
let arrays = {
  range: function(start, stop) {
    let length = stop - start,
        result = new Array(length);

    for (let i = 0, j = start; i < length; i++, j++) {
      result[i] = j;
    }

    return result;
  },

  find: function(array, valueOrPredicate) {
    let length = array.length;

    if (typeof valueOrPredicate === "function") {
      for (let i = 0; i < length; i++) {
        if (valueOrPredicate(array[i])) {
          return array[i];
        }
      }
    } else {
      for (let i = 0; i < length; i++) {
        if (array[i] === valueOrPredicate) {
          return array[i];
        }
      }
    }
  },

  indexOf: function(array, valueOrPredicate) {
    let length = array.length;

    if (typeof valueOrPredicate === "function") {
      for (let i = 0; i < length; i++) {
        if (valueOrPredicate(array[i])) {
          return i;
        }
      }
    } else {
      for (let i = 0; i < length; i++) {
        if (array[i] === valueOrPredicate) {
          return i;
        }
      }
    }

    return -1;
  },

  contains: function(array, valueOrPredicate) {
    return arrays.indexOf(array, valueOrPredicate) !== -1;
  }
};

module.exports = arrays;