Summary

This feature introduces a new String instance method to translate escape sequences to characters.

Problem

Raw String Literals do not interpret Unicode escapes (\unnnn) or escape sequences ( \n, \b, etc). A solution is required to handle scenarios when the developer wants multi-line strings and still have escapes translated.

Solution

Introduce a String instance method, unescape which translates escape sequences to characters.

Specification

    /**
     * Translates all Unicode escapes and escape sequences in this string into
     * characters represented by those escapes specified in sections 3.3 and
     * 3.10.6 of the <cite>The Java&trade; Language Specification</cite>.
     * <p>
     * Backslash escape sequences are translated as follows;
     * <table class="plain">
     *   <caption style="display:none">Escape sequences</caption>
     *   <thead>
     *   <tr>
     *     <th scope="col">Escape</th>
     *     <th scope="col">Name</th>
     *     <th scope="col">Unicode</th>
     *   </tr>
     *   </thead>
     *   <tr>
     *     <td>{@code \b}</td>
     *     <td>backspace</td>
     *     <td>U+0008</td>
     *   </tr>
     *   <tr>
     *     <td>{@code \t}</td>
     *     <td>horizontal tab</td>
     *     <td>U+0009</td>
     *   </tr>
     *   <tr>
     *     <td>{@code \n}</td>
     *     <td>line feed</td>
     *     <td>U+000A</td>
     *   </tr>
     *   <tr>
     *     <td>{@code \f}</td>
     *     <td>form feed</td>
     *     <td>U+000C</td>
     *   </tr>
     *   <tr>
     *     <td>{@code \r}</td>
     *     <td>carriage return</td>
     *     <td>U+000D</td>
     *   </tr>
     *   <tr>
     *     <td>{@code \"}</td>
     *     <td>double quote</td>
     *     <td>U+0022</td>
     *   </tr>
     *   <tr>
     *     <td>{@code \'}</td>
     *     <td>single quote</td>
     *     <td>U+0027</td>
     *   </tr>
     *   <tr>
     *     <td>{@code \\}</td>
     *     <td>backslash</td>
     *     <td>U+005C</td>
     *   </tr>
     * </table>
     * <p>
     * Octal escapes {@code \0 - \377} are translated to their code
     * point equivalents.
     * <p>
     * Each unicode escape in the form &#92;unnnn is translated to a
     * 16-bit 'char' value, which may then be translated as part
     * of backslash escape sequence. For example, "&#92;u005ct" becomes
     * "&#92;t", which then gets translated to tab (U+0009) character.
     *
     * @return String with all escapes translated.
     *
     * @throws IllegalArgumentException when the escape sequence does
     * not conform to JLS 3.3 or 3.10.6.
     *
     * @jls 3.3 Unicode escapes
     * @jls 3.10.6 Escape sequences
     *
     * @since 12
     *
     * @deprecated  Preview feature associated with Raw String Literals.
     */
    @Deprecated(forRemoval=true, since="12")
    public String unescape() {