@instructure/quiz-interactions/lib/util/combinatorics.js

A React UI component Library for quiz interaction types.

function _array_like_to_array(arr, len) {
    if (len == null || len > arr.length) len = arr.length;
    for(var i = 0, arr2 = new Array(len); i < len; i++)arr2[i] = arr[i];
    return arr2;
}
function _array_with_holes(arr) {
    if (Array.isArray(arr)) return arr;
}
function _array_without_holes(arr) {
    if (Array.isArray(arr)) return _array_like_to_array(arr);
}
function _iterable_to_array(iter) {
    if (typeof Symbol !== "undefined" && iter[Symbol.iterator] != null || iter["@@iterator"] != null) return Array.from(iter);
}
function _iterable_to_array_limit(arr, i) {
    var _i = arr == null ? null : typeof Symbol !== "undefined" && arr[Symbol.iterator] || arr["@@iterator"];
    if (_i == null) return;
    var _arr = [];
    var _n = true;
    var _d = false;
    var _s, _e;
    try {
        for(_i = _i.call(arr); !(_n = (_s = _i.next()).done); _n = true){
            _arr.push(_s.value);
            if (i && _arr.length === i) break;
        }
    } catch (err) {
        _d = true;
        _e = err;
    } finally{
        try {
            if (!_n && _i["return"] != null) _i["return"]();
        } finally{
            if (_d) throw _e;
        }
    }
    return _arr;
}
function _non_iterable_rest() {
    throw new TypeError("Invalid attempt to destructure non-iterable instance.\\nIn order to be iterable, non-array objects must have a [Symbol.iterator]() method.");
}
function _non_iterable_spread() {
    throw new TypeError("Invalid attempt to spread non-iterable instance.\\nIn order to be iterable, non-array objects must have a [Symbol.iterator]() method.");
}
function _sliced_to_array(arr, i) {
    return _array_with_holes(arr) || _iterable_to_array_limit(arr, i) || _unsupported_iterable_to_array(arr, i) || _non_iterable_rest();
}
function _to_consumable_array(arr) {
    return _array_without_holes(arr) || _iterable_to_array(arr) || _unsupported_iterable_to_array(arr) || _non_iterable_spread();
}
function _unsupported_iterable_to_array(o, minLen) {
    if (!o) return;
    if (typeof o === "string") return _array_like_to_array(o, minLen);
    var n = Object.prototype.toString.call(o).slice(8, -1);
    if (n === "Object" && o.constructor) n = o.constructor.name;
    if (n === "Map" || n === "Set") return Array.from(n);
    if (n === "Arguments" || /^(?:Ui|I)nt(?:8|16|32)(?:Clamped)?Array$/.test(n)) return _array_like_to_array(o, minLen);
}
import times from 'lodash/fp/times';
import concat from 'lodash/fp/concat';
import map from 'lodash/fp/map';
import reduce from 'lodash/fp/reduce';
import range from 'lodash/fp/range';
import flatten from 'lodash/fp/flatten';
export function identityMatrix(param, size) {
    var _param = _sliced_to_array(param, 2), tmp = _param[0], a = tmp === void 0 ? 1 : tmp, tmp1 = _param[1], b = tmp1 === void 0 ? 0 : tmp1;
    return map(function(row) {
        return times(function(n) {
            return n === row ? a : b;
        }, size);
    }, range(0, size));
}
// same concept as https://github.com/dankogai/js-combinatorics#cartesian-product
export function cartesianProduct() {
    for(var _len = arguments.length, arrays = new Array(_len), _key = 0; _key < _len; _key++){
        arrays[_key] = arguments[_key];
    }
    return reduce(function(a, b) {
        return flatten(map(function(x) {
            return map(function(y) {
                return concat(x, [
                    y
                ]);
            }, b);
        }, a));
    }, [
        []
    ], arrays);
}
// same concept as https://github.com/dankogai/js-combinatorics#base-n
export function baseNCombination(values, n) {
    if (n === 0) {
        return [];
    }
    if (n === 1) {
        return map(function(v) {
            return [
                v
            ];
        }, values);
    }
    var previous = baseNCombination(values, n - 1);
    return cartesianProduct(values, previous).map(function(param) {
        var _param = _sliced_to_array(param, 2), v = _param[0], p = _param[1];
        return [
            v
        ].concat(_to_consumable_array(p));
    });
}
// same concept as https://github.com/dankogai/js-combinatorics#combination
export function combination(array, size) {
    if (size === 0) {
        return [];
    }
    if (size === 1) {
        return map(function(v) {
            return [
                v
            ];
        }, array);
    }
    if (array.length === 1) {
        return [
            times(function() {
                return array[0];
            }, size)
        ];
    }
    if (array.length === 0) {
        return [];
    }
    return concat(map(function(v) {
        return [
            array[0]
        ].concat(_to_consumable_array(v));
    }, combination(array, size - 1)), combination(array.slice(1), size));
}