mathjs/lib/cjs/function/matrix/subset.js

"use strict";

Object.defineProperty(exports, "__esModule", {
  value: true
});
exports.createSubset = void 0;

var _is = require("../../utils/is.js");

var _object = require("../../utils/object.js");

var _array = require("../../utils/array.js");

var _customs = require("../../utils/customs.js");

var _DimensionError = require("../../error/DimensionError.js");

var _factory = require("../../utils/factory.js");

var name = 'subset';
var dependencies = ['typed', 'matrix'];
var createSubset = /* #__PURE__ */(0, _factory.factory)(name, dependencies, function (_ref) {
  var typed = _ref.typed,
      matrix = _ref.matrix;

  /**
   * Get or set a subset of a matrix or string.
   *
   * Syntax:
   *     math.subset(value, index)                                // retrieve a subset
   *     math.subset(value, index, replacement [, defaultValue])  // replace a subset
   *
   * Examples:
   *
   *     // get a subset
   *     const d = [[1, 2], [3, 4]]
   *     math.subset(d, math.index(1, 0))        // returns 3
   *     math.subset(d, math.index([0, 1], 1))   // returns [[2], [4]]
   *
   *     // replace a subset
   *     const e = []
   *     const f = math.subset(e, math.index(0, [0, 2]), [5, 6])  // f = [[5, 6]]
   *     const g = math.subset(f, math.index(1, 1), 7, 0)         // g = [[5, 6], [0, 7]]
   *
   * See also:
   *
   *     size, resize, squeeze, index
   *
   * @param {Array | Matrix | string} matrix  An array, matrix, or string
   * @param {Index} index                     An index containing ranges for each
   *                                          dimension
   * @param {*} [replacement]                 An array, matrix, or scalar.
   *                                          If provided, the subset is replaced with replacement.
   *                                          If not provided, the subset is returned
   * @param {*} [defaultValue=undefined]      Default value, filled in on new entries when
   *                                          the matrix is resized. If not provided,
   *                                          math.matrix elements will be left undefined.
   * @return {Array | Matrix | string} Either the retrieved subset or the updated matrix.
   */
  return typed(name, {
    // get subset
    'Array, Index': function ArrayIndex(value, index) {
      var m = matrix(value);
      var subset = m.subset(index); // returns a Matrix

      return index.isScalar() ? subset : subset.valueOf(); // return an Array (like the input)
    },
    'Matrix, Index': function MatrixIndex(value, index) {
      return value.subset(index);
    },
    'Object, Index': _getObjectProperty,
    'string, Index': _getSubstring,
    // set subset
    'Array, Index, any': function ArrayIndexAny(value, index, replacement) {
      return matrix((0, _object.clone)(value)).subset(index, replacement, undefined).valueOf();
    },
    'Array, Index, any, any': function ArrayIndexAnyAny(value, index, replacement, defaultValue) {
      return matrix((0, _object.clone)(value)).subset(index, replacement, defaultValue).valueOf();
    },
    'Matrix, Index, any': function MatrixIndexAny(value, index, replacement) {
      return value.clone().subset(index, replacement);
    },
    'Matrix, Index, any, any': function MatrixIndexAnyAny(value, index, replacement, defaultValue) {
      return value.clone().subset(index, replacement, defaultValue);
    },
    'string, Index, string': _setSubstring,
    'string, Index, string, string': _setSubstring,
    'Object, Index, any': _setObjectProperty
  });
});
/**
 * Retrieve a subset of a string
 * @param {string} str            string from which to get a substring
 * @param {Index} index           An index containing ranges for each dimension
 * @returns {string} substring
 * @private
 */

exports.createSubset = createSubset;

function _getSubstring(str, index) {
  if (!(0, _is.isIndex)(index)) {
    // TODO: better error message
    throw new TypeError('Index expected');
  }

  if (index.size().length !== 1) {
    throw new _DimensionError.DimensionError(index.size().length, 1);
  } // validate whether the range is out of range


  var strLen = str.length;
  (0, _array.validateIndex)(index.min()[0], strLen);
  (0, _array.validateIndex)(index.max()[0], strLen);
  var range = index.dimension(0);
  var substr = '';
  range.forEach(function (v) {
    substr += str.charAt(v);
  });
  return substr;
}
/**
 * Replace a substring in a string
 * @param {string} str            string to be replaced
 * @param {Index} index           An index containing ranges for each dimension
 * @param {string} replacement    Replacement string
 * @param {string} [defaultValue] Default value to be uses when resizing
 *                                the string. is ' ' by default
 * @returns {string} result
 * @private
 */


function _setSubstring(str, index, replacement, defaultValue) {
  if (!index || index.isIndex !== true) {
    // TODO: better error message
    throw new TypeError('Index expected');
  }

  if (index.size().length !== 1) {
    throw new _DimensionError.DimensionError(index.size().length, 1);
  }

  if (defaultValue !== undefined) {
    if (typeof defaultValue !== 'string' || defaultValue.length !== 1) {
      throw new TypeError('Single character expected as defaultValue');
    }
  } else {
    defaultValue = ' ';
  }

  var range = index.dimension(0);
  var len = range.size()[0];

  if (len !== replacement.length) {
    throw new _DimensionError.DimensionError(range.size()[0], replacement.length);
  } // validate whether the range is out of range


  var strLen = str.length;
  (0, _array.validateIndex)(index.min()[0]);
  (0, _array.validateIndex)(index.max()[0]); // copy the string into an array with characters

  var chars = [];

  for (var i = 0; i < strLen; i++) {
    chars[i] = str.charAt(i);
  }

  range.forEach(function (v, i) {
    chars[v] = replacement.charAt(i[0]);
  }); // initialize undefined characters with a space

  if (chars.length > strLen) {
    for (var _i = strLen - 1, _len = chars.length; _i < _len; _i++) {
      if (!chars[_i]) {
        chars[_i] = defaultValue;
      }
    }
  }

  return chars.join('');
}
/**
 * Retrieve a property from an object
 * @param {Object} object
 * @param {Index} index
 * @return {*} Returns the value of the property
 * @private
 */


function _getObjectProperty(object, index) {
  if (index.size().length !== 1) {
    throw new _DimensionError.DimensionError(index.size(), 1);
  }

  var key = index.dimension(0);

  if (typeof key !== 'string') {
    throw new TypeError('String expected as index to retrieve an object property');
  }

  return (0, _customs.getSafeProperty)(object, key);
}
/**
 * Set a property on an object
 * @param {Object} object
 * @param {Index} index
 * @param {*} replacement
 * @return {*} Returns the updated object
 * @private
 */


function _setObjectProperty(object, index, replacement) {
  if (index.size().length !== 1) {
    throw new _DimensionError.DimensionError(index.size(), 1);
  }

  var key = index.dimension(0);

  if (typeof key !== 'string') {
    throw new TypeError('String expected as index to retrieve an object property');
  } // clone the object, and apply the property to the clone


  var updated = (0, _object.clone)(object);
  (0, _customs.setSafeProperty)(updated, key, replacement);
  return updated;
}