CONCEPT
character escape codes
DESCRIPTION
Character escape codes are used to represent some common
special characters that would be awkward or impossible to
enter in the source program directly. The escape characters
come in two varieties: 'character escapes', which can be
used to represent some particular formatting and special
characters, and 'numeric escapes', which allow a character to
be specified by its numeric encoding.
Escapes begin always with a backslash '\'. If the following
characters could not be treated as a valid escape the backslash
is merely ignored.
The following character escapes are available in LPC (the code
may differ from platform to platform):
\a Code 007 Bell
\b Code 008 Backspace
\e Code 027 Escape
\f Code 012 Formfeed
\n Code 010 Newline
\r Code 013 Carriage-Return
\t Code 009 Tabulator
\\ Code 092 Backslash itself
\' Code 039 Single quote
\" Code 034 Double quote
The single quote may appear without preceding backslash in character
constants, and the double quote may appear without a backslash in
string constants.
The numeric escapes could be used to express a character directly
by its code in binary, octal, decimal or hexadecimal notation.
\0b Beginning of binary notation
\0o Beginning of octal notation
\0x Beginning of hexadecimal notation
\x Beginning of hexadecimal notation
\u, \U Beginning of extended hexadecimal notation
A backslash followed by a digit ([0-9]) which does not map to one
of the above starts an escape in decimal notation.
A numeric escape terminates when N digits have been used up or
when the first character that is not a valid digit in that
notation is encountered. N is 2 for hexadeximals with \0x and \x,
3 for decimals and octals, 4 for hexadecimals with \u,
8 for binarys and for hexadecimals with \U.
If the specified code is greater than 255 a warning is issued and
the value modulo 256 is used (except for \u and \U).
EXAMPLES
Put a newline at the end of user output
"You enter.\n"
Alert the user
"Beeep.\a Wake up\n"
Put a double quote in a string
"You say \"hello\"\n"
Write the line from above
"\"You say \\\"hello\\\"\\n\""
Put a single quote in a string
"You say 'hello'\n"
Some forms to write "abcde"
"abcde"
"ab\99de" (with c's code being 99)
"ab\099de"
"ab\x63de" (99 = 0x63)
"ab\0x63de"
The following string consists of two characters
"\0111" (\011 and 1)
The following string consists of three characters
"\0o090" (\000 and 9 and 0)
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