Move core and coreimpl from corelib/ to lib/core and lib/coreimpl.

corelib/src/string.dart

-// Copyright (c) 2011, the Dart project authors.  Please see the AUTHORS file
-// for details. All rights reserved. Use of this source code is governed by a
-// BSD-style license that can be found in the LICENSE file.
-
-/**
- * The String class represents character strings. Strings are
- * immutable. A string is represented by a list of 32-bit Unicode
- * scalar character codes accessible through the [charCodeAt] or the
- * [charCodes] method.
- */
-interface String
-    extends Comparable, Hashable, Pattern
-    default StringImplementation {
-  /**
-   * Allocates a new String for the specified [charCodes].
-   */
-  String.fromCharCodes(List<int> charCodes);
-
-  /**
-   * Gets the character (as [String]) at the given [index].
-   */
-  String operator [](int index);
-
-  /**
-   * Gets the scalar character code at the given [index].
-   */
-  int charCodeAt(int index);
-
-  /**
-   * The length of the string.
-   */
-  int get length();
-
-  /**
-   * Returns whether the two strings are equal. This method compares
-   * each individual scalar character codes of the strings.
-   */
-  bool operator ==(String other);
-
-  /**
-   * Returns whether this string ends with [other].
-   */
-  bool endsWith(String other);
-
-  /**
-   * Returns whether this string starts with [other].
-   */
-  bool startsWith(String other);
-
-  /**
-   * Returns the first location of [other] in this string starting at
-   * [start] (inclusive).
-   * Returns -1 if [other] could not be found.
-   */
-  int indexOf(String other, [int start]);
-
-  /**
-   * Returns the last location of [other] in this string, searching
-   * backward starting at [start] (inclusive).
-   * Returns -1 if [other] could not be found.
-   */
-  int lastIndexOf(String other, [int start]);
-
-  /**
-   * Returns whether this string is empty.
-   */
-  bool isEmpty();
-
-  /**
-   * Creates a new string by concatenating this string with [other].
-   */
-  String concat(String other);
-
-  /**
-   * Returns a substring of this string in the given range.
-   * [startIndex] is inclusive and [endIndex] is exclusive.
-   */
-  String substring(int startIndex, [int endIndex]);
-
-  /**
-   * Returns a new string where leading and trailing whitespaces of
-   * this string have been removed, or returns this string if it does
-   * not have leading and trailing whitespaces.
-   */
-  String trim();
-
-  /**
-   * Returns whether this string contains [other] starting
-   * at [startIndex] (inclusive).
-   */
-  bool contains(Pattern other, [int startIndex]);
-
-  /**
-   * Returns a new string where the first occurence of [from] in this string
-   * is replaced with [to].
-   */
-  String replaceFirst(Pattern from, String to);
-
-  /**
-   * Returns a new string where all occurences of [from] in this string
-   * are replaced with [to].
-   */
-  String replaceAll(Pattern from, String to);
-
-  /**
-   * Splits the string around matches of [pattern]. Returns
-   * a list of substrings.
-   */
-  List<String> split(Pattern pattern);
-
-  /**
-   * Returns a list of the characters of this string.
-   */
-  List<String> splitChars();
-
-  /**
-   * Returns a list of the scalar character codes of this string.
-   */
-  List<int> charCodes();
-
-  /**
-   * If this string is not already all lower case, returns a new string
-   * where all characters  are made lower case. Returns [:this:] otherwise.
-   */
-  String toLowerCase();
-
-  /**
-   * If this string is not already all uper case, returns a new string
-   * where all characters are made upper case. Returns [:this:] otherwise.
-   */
-  String toUpperCase();
-}