add hw2

node_modules/lodash/truncate.js

@@ -0,0 +1,111 @@
+var baseToString = require('./_baseToString'),
+    castSlice = require('./_castSlice'),
+    hasUnicode = require('./_hasUnicode'),
+    isObject = require('./isObject'),
+    isRegExp = require('./isRegExp'),
+    stringSize = require('./_stringSize'),
+    stringToArray = require('./_stringToArray'),
+    toInteger = require('./toInteger'),
+    toString = require('./toString');
+
+/** Used as default options for `_.truncate`. */
+var DEFAULT_TRUNC_LENGTH = 30,
+    DEFAULT_TRUNC_OMISSION = '...';
+
+/** Used to match `RegExp` flags from their coerced string values. */
+var reFlags = /\w*$/;
+
+/**
+ * Truncates `string` if it's longer than the given maximum string length.
+ * The last characters of the truncated string are replaced with the omission
+ * string which defaults to "...".
+ *
+ * @static
+ * @memberOf _
+ * @since 4.0.0
+ * @category String
+ * @param {string} [string=''] The string to truncate.
+ * @param {Object} [options={}] The options object.
+ * @param {number} [options.length=30] The maximum string length.
+ * @param {string} [options.omission='...'] The string to indicate text is omitted.
+ * @param {RegExp|string} [options.separator] The separator pattern to truncate to.
+ * @returns {string} Returns the truncated string.
+ * @example
+ *
+ * _.truncate('hi-diddly-ho there, neighborino');
+ * // => 'hi-diddly-ho there, neighbo...'
+ *
+ * _.truncate('hi-diddly-ho there, neighborino', {
+ *   'length': 24,
+ *   'separator': ' '
+ * });
+ * // => 'hi-diddly-ho there,...'
+ *
+ * _.truncate('hi-diddly-ho there, neighborino', {
+ *   'length': 24,
+ *   'separator': /,? +/
+ * });
+ * // => 'hi-diddly-ho there...'
+ *
+ * _.truncate('hi-diddly-ho there, neighborino', {
+ *   'omission': ' [...]'
+ * });
+ * // => 'hi-diddly-ho there, neig [...]'
+ */
+function truncate(string, options) {
+  var length = DEFAULT_TRUNC_LENGTH,
+      omission = DEFAULT_TRUNC_OMISSION;
+
+  if (isObject(options)) {
+    var separator = 'separator' in options ? options.separator : separator;
+    length = 'length' in options ? toInteger(options.length) : length;
+    omission = 'omission' in options ? baseToString(options.omission) : omission;
+  }
+  string = toString(string);
+
+  var strLength = string.length;
+  if (hasUnicode(string)) {
+    var strSymbols = stringToArray(string);
+    strLength = strSymbols.length;
+  }
+  if (length >= strLength) {
+    return string;
+  }
+  var end = length - stringSize(omission);
+  if (end < 1) {
+    return omission;
+  }
+  var result = strSymbols
+    ? castSlice(strSymbols, 0, end).join('')
+    : string.slice(0, end);
+
+  if (separator === undefined) {
+    return result + omission;
+  }
+  if (strSymbols) {
+    end += (result.length - end);
+  }
+  if (isRegExp(separator)) {
+    if (string.slice(end).search(separator)) {
+      var match,
+          substring = result;
+
+      if (!separator.global) {
+        separator = RegExp(separator.source, toString(reFlags.exec(separator)) + 'g');
+      }
+      separator.lastIndex = 0;
+      while ((match = separator.exec(substring))) {
+        var newEnd = match.index;
+      }
+      result = result.slice(0, newEnd === undefined ? end : newEnd);
+    }
+  } else if (string.indexOf(baseToString(separator), end) != end) {
+    var index = result.lastIndexOf(separator);
+    if (index > -1) {
+      result = result.slice(0, index);
+    }
+  }
+  return result + omission;
+}
+
+module.exports = truncate;