Escape Sequences
RWUString provides the
unescape() method that replaces hexadecimal character escapes with their corresponding Unicode characters. The recognized escape sequences are shown in
Table 1. The value of any other escape sequence is the value of the character that follows the backslash.
Table 1 – Recognized Escape Sequences
Escape Sequence | Unicode |
|---|
\uhhhh | 4 hexadecimal digits in the range [0-9A-Fa-f] |
\Uhhhhhhhh | 8 hexadecimal digits |
\xhh | 1 or 2 hexadecimal digits |
\ooo | 1, 2, or 3 octal digits in the range [0-7] |
\a | U+0007: alert (BEL) |
\b | U+0008: backspace (BS): |
\t | U+0009: horizontal tab (HT) |
\n | U+000A: newline/line feed (LF) |
\v | U+000B: vertical tab (VT) |
\f | U+000C: form feed (FF) |
\r | U+000D: carriage return (CR) |
\" | U+0022: double quote |
\' | U+0027: single quote |
\? | U+003F: question mark |
\\ | U+005C: backslash |
Note that when you create an
RWUString from a string literal containing an escaped character, you must use a double-backslash sequence to escape characters, as the C++ compiler itself treats the
\ character as special, denoting the beginning of an escape sequence embedded in the C++ source code. For example:
RWUToUnicodeConverter fromAscii("US-ASCII");
RWUString str("clich\\u00e9", fromAscii);
RWUFromUnicodeConverter toAscii("US-ASCII");
std::cout << str.toBytes(toAscii) << std::endl;
std::cout << str.unescape().toBytes(toAscii) << std::endl;
Results:
========
clich\u00e9
cliché
If an escape sequence is ill-formed,
unescape() throws an
RWConversionErr. (See this class entry in the SourcePro
C++ API Reference Guide.)
